JP2006070000A - Preparation method of dimethyl naphthalenedicarboxylate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a preparation method of dimethyl naphthalenedicarboxylate. <P>SOLUTION: The preparation method of the dimethyl naphthalenedicarboxylate comprises (a) an alkenylation step wherein an alkenylated product is prepared from an aromatic hydrocarbon and dienes, (b) a cyclization and dehydrogenation step wherein the alkenylated product is cyclized to prepare dimethyltetralin which is subsequently dehydrogenated to prepare dimethylnaphthalene, (c) an isomerization step of the dimethylnaphthalene, (d) an oxidation step wherein the dimethylnaphthalene is oxidized to prepare naphthalenedicarboxylic acid and (e) an esterification step wherein the naphthalenedicarboxylic acid is esterified in the presence of methanol to prepare the dimethyl naphthalenedicarboxylate. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates generally to the synthesis of naphthalene compounds, and more particularly to a process for efficiently and industrially producing certain isomers of dimethyl naphthalenedicarboxylate and the use of these synthetic intermediates.

  The synthesis of dimethyl 2,6-naphthalenedicarboxylate (2,6-NDCM) typically involves several steps. In a typical synthesis, orthoxylene and butadiene are reacted over an alkali metal or other catalyst to give 5- (o-tolyl) -2-pentene (5-OTP). The 5-OTP is then cyclized over an acid catalyst to give 1,5-dimethyltetralin (1,5-DMT). 1,5-DMT is dehydrogenated over a noble metal or other dehydrogenation catalyst to give 1,5-dimethylnaphthalene (1,5-DMN) followed by isomerization to 2,6-dimethyl. Naphthalene (2,6-DMN) is produced (see, for example, Patent Documents 1 to 4).

  Once 2,6-DMN is produced, it is oxidized to produce 2,6-naphthalenedicarboxylic acid (2,6-NDCA), followed by esterification to produce 2,6-NDCM (eg, (See Patent Documents 5 to 6). Next, this 2,6-NDCM is polymerized in the presence of ethylene glycol, for example, to produce polyethylene naphthalate (PEN) useful as a monomer or comonomer in the above-mentioned applications (see, for example, Patent Document 7).

  Films made from 2,6-NDCM-based polymers exhibit strength and thermal properties superior to films and fibers made from other polymers such as polyethylene terephthalate (PET). Due to these enhanced properties, 2,6-NDCM based polymers are used in camera films and magnetic recording tapes as well as electrical and electronic components.

  The excellent physical strength of 2,6-NDCM polymers further makes these polymers useful for applications that require physical strength such as cords for automobile tires and motorcycle tires.

  2,6-NDCM-based polymers are characterized by low permeability of gases such as carbon dioxide, water vapor and oxygen. Because of this property called gas barrier, these polymers can be used in a wide range of food and beverage packaging applications films and containers.

Japanese Patent No. 2853720 Japanese Patent No. 2885260 Japanese Patent No. 2891272 Japanese Patent No. 3013867 Japanese Patent No. 3390169 Japanese Patent Publication No.49-174 Japanese Patent No. 2824716

However, as noted above, commercial scale 2,6-NDCM synthesis is a very complex and multi-step process when compared to other dicarboxylic acids used as polymer raw materials such as terephthalic acid. In addition, the unit price of 2,6-NDCM is high.
In addition, the 2,6-NDCM polymer has excellent physical strength, but at the same time has a characteristic of becoming hard, and thus has disadvantages such as poor processability and poor flexibility. For this reason, compared with PET etc., it is a cause that a use is not expanded widely generally. It is known that the gas barrier property is slightly inferior to other polymers having gas barrier properties such as vinyl alcohol-ethylene copolymer.

  An object of the present invention is to provide a method for clearing problems such as cost in conventional 2,6-NDCM production and quality of 2,6-NDCM polymer.

  In order to solve the above-mentioned problems, the present inventors have intensively studied. As a result, it was found that isomers of NDCM other than 2,6-can be produced by changing raw materials in an apparatus for producing 2,6-NDCM, without major changes on the apparatus. It has been found that these isomers can increase the economic viability of naphthalene monomers in many applications by replacing some or all of the 2,6-NDCM based materials. By selecting any one of toluene, para-xylene, meta-xylene, and ethylbenzene as the raw material aromatic hydrocarbon, and any one of butadiene and isoprene as the raw material diene, It was found that-, 1,4-, 1,6-, 1,7-, 2,3-, 2,7-NDCM can be produced. Further, it has been clarified that unprecedented flexibility and gas barrier properties are exhibited by using part or all of these NDCM isomers as polymerization raw materials for PET and 2,6-NDCM polymers. By switching and producing such a high value-added product group, the price of each isomer can be reduced synergistically, making it possible to produce a naphthalene monomer more efficiently and at a low cost. Reached.

That is, the present invention provides a manufacturing method comprising the following steps (a), (b), (c), (d) and (e), or (a), (b), (d) and (e). A method for producing dimethyl naphthalenedicarboxylate, comprising producing two or more isomers of dimethyl naphthalenedicarboxylate by changing a combination of aromatic hydrocarbons and dienes as raw materials using an operating production apparatus I will provide a.
In addition, the present invention provides aromatic carbonization by the following steps (a), (b), (c), (d) and (e), or (a), (b), (d) and (e). Production of isomers selected from 1,2-, 1,4-, 1,6-, 1,7-, 2,3- and 2,7-isomers using hydrogen and dienes as starting materials A method for producing dimethyl naphthalenedicarboxylate is provided.
(A) An alkenylation step for producing an alkenylated product from an aromatic hydrocarbon and a diene. (B) A ring for producing dimethylnaphthalene by producing dimethyltetralin by cyclization of the alkenylated product and then dehydrogenating dimethyltetralin. (C) Dimethylnaphthalene isomerization step (d) Dimethylnaphthalene is oxidized to produce naphthalene dicarboxylic acid (e) Naphthalene dicarboxylic acid is esterified in the presence of methanol to form naphthalene dicarboxylic acid Esterification process to produce dimethyl acid

  As is clear from the above examples, according to the present invention, 1,2-, 1,4-, 1,6-, 1,7-, 2,3-, 2,6-, 2,7-naphthalenedicarboxyl are used. Dimethyl acid can be produced efficiently at low cost.

  As described above, 2,6-NDCM is obtained from alkenylation, cyclization / dehydrogenation, isomerization (1,1) using ortho-xylene and 1,3-butadiene (hereinafter sometimes simply referred to as butadiene) as starting materials. 5-DMN to 2,6-DMN), obtained by oxidation and esterification. Further, 1,5-DMN obtained as an intermediate here is oxidized and esterified to obtain 1,5-NDCM.

  In the present invention, 1,2-, 1,4-, 1,6-, 1,7-, 2,3- and 2,7-NDCM (hereinafter sometimes referred to as specific isomers) are efficiently used. Can be manufactured. 1,4-, 1,6-, 1,7-, 2,3- or 2,7-NDCM can be obtained by changing the raw material from ortho-xylene to para-xylene, meta-xylene or ethylbenzene. It is done. Further, 1,2-NDCM can be obtained by changing ortho-xylene to toluene and butadiene to isoprene (2-methyl-1,3-butadiene). That is, these specific isomers can be produced together with 2,6-NDCM and 1,5-NDCM using a 2,6-NDCM production plant. In this invention, it operates by the manufacturing method which consists of the following (a), (b), (c), (d) and (e) or (a), (b), (d) and (e) processes. Selected from 1,2-, 1,4-, 1,5-, 1,6-, 1,7-, 2,3-, 2,6- and 2,7-forms using production equipment Two or more isomers of NDCM can be produced. The ability to produce products that excel in many applications without particularly large process step changes can synergistically reduce the fixed costs of the production plant and reduce the price of each product. Moreover, it is also possible to make each above-mentioned specific isomer using the apparatus which manufactured dormant 2,6-NDCM.

(A) Alkenylation step As the first step, alkenylation is performed. As the raw material aromatic hydrocarbon, one selected from toluene, ortho-xylene, para-xylene, meta-xylene and ethylbenzene is used, and when producing the specific isomer, from toluene, para-xylene, meta-xylene and ethylbenzene. What is chosen is used. As the starting dienes, conjugated dienes having 4 or 5 carbon atoms are used. Specifically, in the synthesis of 3-methyl-5-phenyl-2-pentene, which is an alkenylated precursor of 1,2-NDCM, toluene and isoprene are substituted for 1,4- and 2,3-NDCM precursors. In the synthesis of 5-phenyl-2-hexene, which is an alkenylated product of 1,6-NDM, ethylbenzene and butadiene are synthesized, and in the synthesis of 5-methatoryl-2-pentene, which is an alkenylated precursor of 1,6-NDCM, xylene and butadiene are synthesized. In the synthesis of 5-paratoluyl-2-pentene, which is an alkenylation product of precursors of 1,7- and 2,7-NDCM, paraxylene and butadiene are respectively selected as raw materials.

  A preferred method for carrying out this alkenylation reaction is 0.01-2 MPa at a temperature between about 90-200 ° C. in the presence of a stoichiometric excess of at least 5: 1 aromatic hydrocarbons versus dienes. The use of a mixture of potassium compound and sodium metal as catalyst with a residence time of about 0.1 to 10 hours at a pressure in between. The reaction is preferably quenched by the addition of water, alcohol or mixtures thereof, followed by separation of the alkenylate by means known in the art.

(B) Cyclization / dehydrogenation step As the second step, the alkenylated product is cyclized to prepare a dimethyltetralin intermediate, and then dehydrogenation is performed to synthesize dimethylnaphthalene. Cyclization reactions useful for this are well known and typically involve reacting the above alkenyl compound over a solid acid catalyst. Since higher selectivity is preferable, 0.01 to 0.5 times by weight of crystalline aluminosilicate is combined with one or more carriers selected from carbon, silicon oxide, titanium oxide, and zirconium oxide. A process using a catalyst is preferred. It is also possible to prepare dimethyltetralin by extracting a distillation fraction and, if necessary, performing crystallization or the like.

  The cyclization reaction is preferably performed at an elevated temperature between about 150-250 ° C. and a pressure of about 0.03-0.5 MPa. It is also possible to use a diluent in order to carry out the reaction in the gas phase. The diluent is not particularly limited as long as it is inert under the reaction conditions and can keep the reaction system in a gas phase, for example, gaseous substances such as nitrogen, carbon dioxide, hydrogen, argon, helium, or the like Examples thereof include saturated hydrocarbons such as propane, butane, pentane, hexane and heptane, alicyclic hydrocarbons such as cyclopentane and cyclohexane, and aromatic hydrocarbons such as benzene, toluene and xylene. Water should be removed from the reaction mixture.

Dehydrogenation of the dimethyltetralin intermediate can be accomplished, for example, by using any solid dehydrogenation catalyst that has a lifetime that is commercially tolerable under the dehydrogenation conditions used. Typically, the catalyst is a noble metal on activated carbon or an alumina support and contains up to about 15 wt% noble metal, based on the total weight of the catalyst. When carried out in the presence of a catalyst comprising platinum and potassium on a zinc aluminate spinel support, the life of the catalyst is improved.
Suitable temperature and pressure process conditions for carrying out the dehydrogenation reaction with these and other catalysts are substantially the same as those described above for the cyclization reaction. As the noble metal, platinum and / or palladium is preferably used.

  Normally, there is only one major isomer in the process so far, but only when a combination of metaxylene and butadiene is selected as a raw material, the two isomers of 1,6-dimethyltetralin and 1,8-dimethyltetralin are selected. A mixture is synthesized. However, when the above-described dehydrogenation process is performed, only 1,6-dimethyltetralin is dehydrogenated to 1,6-DMN. Therefore, a mixture of 1,8-dimethyltetralin and 1,6-DMN is obtained as a reaction product. Due to this difference in reactivity, DMN isomers are usually very difficult to separate by distillation or the like because their boiling points are close to each other. However, these two compounds can be easily separated, and thus have high purity. 1,6-DMN can be obtained.

  The above process synthesizes 1,2-DMN from toluene and isoprene, 1,4-DMN from ethylbenzene and butadiene, 1,6-DMN from metaxylene and butadiene, and 1,7-DMN from paraxylene and butadiene. Is done. When the corresponding dimethyl ester derived from DMN is necessary, it is usually sent as it is or after performing known purification such as crystallization and distillation, and then sent to the oxidation step.

(C) Isomerization step When 2,3-DMN and 2,7-DMN are required, a step of isomerizing 1,4-DMN and 1,7-DMN, respectively, is performed. As a typical isomerization step, a solid catalyst containing alumina and / or silica is used as a catalyst, and preferably a mordenite composed of a substantially hydrogen type having a silica to alumina molar ratio of 100 or more is used in the liquid phase. To isomerize. The isomerization temperature is preferably 270 ° C. or lower. In the case of 1,4-DMN after the isomerization reaction, a mixture of 1,3-, 1,4-, 2,3-isomers is obtained. Using these solvents, solvents such as saturated hydrocarbons such as propane, butane, pentane, hexane and heptane, alicyclic hydrocarbons such as cyclopentane and cyclohexane, and aromatic hydrocarbons such as benzene, toluene and xylene are used. By performing crystallization, only 2,3-DMN having the highest melting point can be taken out with high purity. Similarly, 1,7-DMN becomes a mixture of 1,7-isomer and 2,7-isomer after isomerization, but only 2,7-DMN having a high melting point can be obtained by crystallization with high purity.
The mother liquor containing the mixture of isomers after crystallization is sent again to the isomerization step and recycled.

(D) Oxidation Step NDCA is typically conducted at a reaction temperature of about 100-260 ° C. in the presence of a molecular oxygen source, a solvent containing a monocarboxylic acid and water, a catalyst containing cobalt, manganese and bromine components. And produced by liquid phase oxidation of DMN. The ratio of catalyst component to solvent to feedstock is experienced at reaction temperature and pressure conditions selected to minimize the formation of undesirable reaction products and to minimize the presence of residual catalytic metals in the NDCA product. Can be determined. The reaction is preferably carried out in a monocarboxylic acid solvent such as acetic acid or a mixture of acetic acid and water. Here, the solvent: DMN ratio is about 2: 1 to 25: 1, the manganese: cobalt ratio is about 10: 1 to 0.1: 20, and the bromine: manganese and cobalt ratio is about 0.3: 1 to 1.5: 1 and the total amount of cobalt and manganese is up to 1 wt% of the selected solvent.
By this oxidation step, the corresponding isomeric NDCA can be obtained from DMN. Here, in order to obtain a highly pure NDCA isomer, it is preferable that the isomer purity of DMN is high.

  Prior to esterification to NDCM, it is preferred to purify the NDCA prepared in the manner described above by one or more purification steps in order to improve the purity and yield of the final NDCM product. Suitable purification methods include recrystallization, solvent washing and / or distillation.

(E) Esterification Step Esterification of NDCA to NDCM typically involves the use of an acid catalyst such as sulfuric acid or paratoluenesulfonic acid, and a mixture of methanol and NDCA at a pressure of about 0.1 to 4 MPa. Below, it is achieved by heating to a temperature between about 65-200 ° C. with a residence time on the order of 20-300 minutes. Preferred temperature and pressure conditions are between 0.3 and 1.5 MPa at about 90-150 ° C. The temperature and pressure should be selected such that a portion of the methanol is maintained in the liquid phase while this esterification reaction occurs. Alternatively, a mixture of methanol, NDCA, and NDCM acting as a substantial solvent can be used at a pressure of about 40-100 atmospheres with a residence time on the order of 20-300 minutes between about 200-300 ° C. It is also achieved by heating to temperature.

  As with NDCA feedstocks, purification of the esterification product (NDCM) is preferred prior to use as a monomer in the production of resins such as polyester, such purification typically involves solvent washing of the reaction mixture, It can be achieved by recrystallization and / or vacuum distillation.

  In the apparatus for producing 2,6-NDCM by the above-described method, 1,2-, 1,4-, 1,6-, 1,7-, 2,3--2 can be freely changed by changing raw materials. , 7-, each of the high purity NDCM isomers can be produced. Moreover, intermediates such as DMN and NDCA can be freely taken out if necessary.

  1,2-, 1,4-, 1,6-, 1,7-, 2,3- or 2,7-isomers of NDCM (specific isomers), or intermediates in these production methods Polymers such as polyamide and polyester having at least one naphthalene dicarboxyl moiety and / or naphthalene carboxylate moiety derived from each of these isomers using each isomer of NDCA obtained as a monomer (dicarboxylic acid component) Has unprecedented physical properties.

  Further, dicarboxylic acid components other than these isomers include succinic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, adipic acid, sebacic acid, undecanedioic acid, dodecanedioic acid and other aliphatic dicarboxylic acids, isophthalic acid, etc. Aromatic acids, terephthalic acid, 1,3-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 4,4′-biphenyldicarboxylic acid, 3,4′-biphenyldicarboxylic acid, etc. Dicarboxylic acids and their derivatives can also be copolymerized. Furthermore, monocarboxylic acids such as benzoic acid, propionic acid and butyric acid, polycarboxylic acids such as trimellitic acid and pyromellitic acid, trimellitic anhydride, pyromellitic anhydride, etc. Can be used.

  The diamine components that constitute the polyamide together with these isomers include tetramethylene diamine, pentamethylene diamine, 2-methylpentane diamine, hexamethylene diamine, heptamethylene diamine, octamethylene diamine, nonamethylene diamine, decamethylene diamine, dodeca diamine. Aliphatic diamines such as methylenediamine, 2,2,4-trimethyl-hexamethylenediamine, 2,4,4-trimethylhexamethylenediamine, 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) ) Cyclohexane, 1,3-diaminocyclohexane, 1,4-diaminocyclohexane, bis (4-aminocyclohexyl) methane, 2,2-bis (4-aminocyclohexyl) propane, bis (aminomethyl) decalin, Alicyclic diamines such as bis (aminomethyl) tricyclodecane, bis (4-aminophenyl) ether, orthophenylenediamine, metaphenylenediamine, paraphenylenediamine, metaxylylenediamine, paraxylylenediamine, bis (aminomethyl) ) Diamines having an aromatic ring such as naphthalene. Furthermore, lactams such as caprolactam, valerolactam, laurolactam, and undecalactam, and aminocarboxylic acids such as 11-aminoundecanoic acid and 12-aminododecanoic acid may be used.

  Examples of the diol component constituting the polyester include aliphatic diols such as ethylene glycol, 1,3-propylene diol, 1,4-butanediol, 1,4-cyclohexanedimethanol, 1,6-hexanediol, Examples thereof include aromatic diols such as 4-benzenedimethanol, 1,3-benzenedimethanol, and 2,6-naphthalenediethanol, and ester-forming derivatives thereof. Furthermore, monoalcohols such as butyl alcohol, hexyl alcohol and octyl alcohol, and polyhydric alcohols such as trimethylolpropane, glycerin and pentaerythritol can be used within the range not impairing the object of the present invention.

  Fibers, films, and molded articles containing the polymer of the present invention have unprecedented characteristics. For example, flexibility, gas barrier properties, processability, and the like are improved as compared with a polymer having only 2,6-NDCM as a naphthalene dicarboxylate moiety. For example, when polymerizing with ethylene glycol, a part or all of 2,6-NDCM is 1,2-, 1,4-, 1,6-, 1,7-, 2,3-, 2,7-NDCM. When replaced by any of the isomers, an amorphous density higher than 2,6-PEN is exhibited. This high density correlates with excellent barrier properties, which means that it is a preferred material for packaging applications, i.e. where good barrier properties are important to maintain the quality of the packaged material. . At the same time, the glass transition point and melting point are lowered, which means that it is particularly useful for the production of molded products. Other uses include a wide range of uses such as polyester modifiers, epoxy resin curing agents, raw materials for medicines and agricultural chemicals, and raw materials for lubricating oils.

Next, the present invention will be specifically described by the following examples. However, the present invention is not limited by these examples.
The yield of the target product in each example was calculated from the results of gas chromatography analysis of the reaction product.

<Reference Example (Production of 2,6-NDCM)>
A process for producing 2,6-NDCM from orthoxylene and butadiene will be described with reference to the drawings. The correspondence between each process and the drawing is as follows (the same applies to the following examples).
Fig. 1: (a) Alkenylation step Fig. 2: (b) Cyclization / dehydrogenation step Fig. 3: (c) Isomerization step Fig. 4: (d) Oxidation step Fig. 5: (e) Esterification step

(A) 30 parts of zirconium oxide powder was added to an aqueous solution containing 5 parts of alkenylated potassium hydroxide and impregnated with stirring at 50 ° C. for 1 hour. Water was distilled off at 70 ° C. under reduced pressure, dried at 115 ° C. overnight, and further calcined at 500 ° C. in air. 10 parts of the catalyst thus obtained was supplied to the alkenylation reactor 3 and stirred at 180 ° C. in a nitrogen atmosphere. After adding 0.5 parts of sodium metal, the mixture was stirred at that temperature for 60 minutes. 1000 parts of orthoxylene were fed to the alkenylation reactor 3 and heated to 140 ° C. While vigorously stirring, 70 parts of 1,3-butadiene was introduced in 1 hour to carry out a batch reaction. After completion of the reaction, the reaction mixture was cooled, transferred to the catalyst decomposition tank 5 from the flow path 4, and 50 parts of 10% aqueous sulfuric acid solution was supplied from the flow path 6 while stirring. The yield per ortho-xylene reacted with 5-OTP was 82%. After the upper layer is transferred to the intermediate tank 8 through the flow path 7, it is transferred to the 23 kPa low boiling cut tower 10 at 63 parts / hr. The low boiling point was distilled off in the flow path 11. The low boiling point could be reused for the alkenylation reaction. The column bottom liquid is extracted through the flow path 12, and the high boiling point is 2 parts / hr. While being extracted, 10 parts / hr. Of 5-OTP is transferred from the flow path 15 to the intermediate tank 16. Extracted.

(B) Cyclization / dehydrogenation step 500 parts of pure water was added to 15 parts of Tosoh H-type mordenite, 270 parts of silica, and 21 parts of alumina sol having an alumina content of 70% by weight as a binder, and the mixture was well mixed and stirred at room temperature. Then, after shaping | molding using an extruder, it dried at 110 degreeC and baked at 350 degreeC for 3 hours, and prepared the catalyst. The cyclization reactor 18 was charged with this catalyst, the reaction temperature was 170 ° C. under normal pressure, and 10 parts / hr. And at a rate of 250 parts nitrogen / min. The cyclization reaction was carried out. The molar ratio of the diluent to the raw material was 11. After the cyclization reaction, the dehydrogenation reactor 20 filled with 40 parts of 1% platinum / activated carbon catalyst (manufactured by NE Chemcat) was continuously supplied from the flow path 19. The reaction temperature was 280 ° C. As a diluting solvent, heptane is 20 parts / hr. The dehydrogenation reaction was carried out while supplying them simultaneously. After the reaction, the solvent was supplied from the flow path 21 to the solvent recovery tower 22 decompressed to 19 kPa, and heptane was recovered from the flow path 23. After heptane recovery, the low boiling point is supplied from the flow path 24 to the low boiling high boiling cut tower 25 which has been depressurized to 13 kPa. The high boiling point is 0.3 parts / hr. Then, 9.4 parts of 98% pure 1,5-DMN was extracted from the middle stage of the tower through the flow path 28 to the intermediate tank 29.

(C) Isomerization process 100 parts of H-type mordenite (manufactured by Tosoh) having a SiO ₂ / Al ₂ O ₃ ratio of 203 and 20 parts of alumina sol (alumina 70 wt% produced by catalytic conversion) were added to pure water and well kneaded. After drying at 110 ° C., the mixture was calcined at 500 ° C. for 2 hours in the air, and crushed to collect particles having a particle size of 1.0 to 2.0 mm as a catalyst. 20 parts of this catalyst was charged into the isomerization reactor 31. 1,5-DMN in the intermediate tank 29 from the flow path 30 and 9.4 parts / hr. From the lower part of the isomerization reactor. The isomerization reaction was carried out at 255 ° C. under normal pressure. The reaction product solution is supplied from the flow path 32 to the crystallization tank 33 and diluted with heptane 5 parts / hr. In addition, 2,6-DMN was precipitated by being cooled to 25 ° C. in the crystallization tank 33. The slurry liquid was supplied to the solid-liquid separator 35 through the flow path 34, and filtered and rinsed. The separated mother liquor contained 6 parts of a mixture of DMN isomers. The flow path 36 can be recycled to the solvent recovery tower 22. The crystal after rinsing was heated and dissolved from the flow path 37 and then supplied to the low boiling cut tower 38 decompressed to 19 kPa. One part of low boiling point is extracted by the flow path 39, and 2,6-DMN having a purity of 99% is extracted from the flow path 40 by 3 parts / hr. Was extracted and supplied to the intermediate tank 41.

(D) Oxidation step Titanium oxidation reactor 45 equipped with a gas discharge pipe with a reflux condenser, a gas introduction pipe, and a stirrer was charged with 3 parts / hr. Was supplied by the flow path 42. At the same time, the flow path 43 was used to add 36 parts / hr. Of 95% aqueous acetic acid having a Br ion concentration of 1600 ppm, a manganese concentration of 2500 ppm, and a cobalt concentration of 400 ppm. Supplied. The amount of air supplied from the channel 44 was adjusted so that the oxygen concentration of the Off gas in the channel 46 was 1 to 5%. The reaction pressure was 1.8 MPa, and the temperature was 200 ° C. A part of the return of the reflux was extracted from the channel 47, and a part of the oxidation reaction water was continuously extracted. The reaction solution was continuously withdrawn into the intermediate tank 49 at normal pressure through the channel 48 so that the amount of solution in the oxidation reactor was constant at 70 parts. The oxidation reaction liquid was supplied from the flow path 50 by the solid-liquid separator 51, and the separated cake was supplied from the flow path 52 to the dryer 54 to recover acetic acid. Part or all of the separated mother liquor obtained from the flow path 53 can be recycled to the oxidation reactor 45 by adjusting the catalyst concentration and water concentration.
The dried crystals are 97% 2,6-NDCA, 3.6 parts / hr. Thus, the intermediate silo 56 is continuously filled from the flow path 55.

(E) Esterification Step From the intermediate silo 56, 36 parts of crystals were supplied to the esterification reactor 58 through the flow path 57, and 360 parts of methanol and 3.6 parts of sulfuric acid were simultaneously supplied. The esterification reactor was heated to 130 ° C. and 1.3 MPa, and the pressure was increased for 3 hours. The batch reaction was performed with stirring. The yield of 2,6-NDCM was 99.8%. After completion of the reaction, the reaction solution was transferred to the crystallization tank 61 through the channel 60 and cooled to 30 ° C. to precipitate a solid. The obtained slurry was fed at 36 parts / hr. To the solid-liquid separator 63. The separated cake was supplied to the dryer 66 through the flow path 64 to recover the attached methanol. The separation mother liquor in the channel 65 was discarded after the methanol was recovered. The dried crystals were 3.8 parts / hr. Was supplied to a distillation column 68 which was dissolved and depressurized to 2 kPa through a channel 67. In the distillation tower 68, the high boiling point is 0.2 parts / hr. While extracting, 2,6-NDCM was extracted from the channel 70. 2,6-NDCM in the flow path 70 was added to the dissolution tank 71 at 10 parts / hr. At the same time supplied. In the dissolution tank 71, 2,6-NDCM was completely dissolved under conditions of normal pressure and 130 ° C. This solution was supplied to the crystallization tank 73 through the flow path 72, cooled to 30 ° C., and 2,6-NDCM was crystallized. The slurry liquid after crystallization was supplied to the solid-liquid separator 75 from the flow path 74, separated and rinsed, and then supplied to the dryer 78 from the flow path 76 to recover metaxylene. The separated mother liquor obtained from the flow path 77 was recycled to the distillation column 68 after recovering meta-xylene. The dried 2,6-NDCM was supplied to the distillation column 80 which was dissolved and depressurized to 2 kPa from the flow path 79. High boiling point from the channel 81 is 0.05 parts / hr. Extracted. This high boiling point could be recycled to the distillation column 68. From the flow channel 82, 3.5 parts / hr. Extracted 9,6-NDCM with a purity of 99.5%.

<Example 1 (Production of 1,4-NDCM)>
The same apparatus was used according to the reference example except that the raw material was changed from orthoxylene to ethylbenzene.

(A) The catalyst treated in the same manner as in the alkenylation reference example and 2000 parts of ethylbenzene were supplied to the alkenylation reactor 3 and heated to 130 ° C. While vigorously stirring, 100 parts of 1,3-butadiene was introduced in 1 hour to carry out a batch reaction. After completion of the reaction, the reaction mixture was cooled, transferred to the catalyst decomposition tank 5 from the flow path 4, and 50 parts of 10% aqueous sulfuric acid solution was supplied from the flow path 6 while stirring. The yield per ethylbenzene reacted with 5-phenyl-2-hexene was 55%. After the upper layer is transferred to the intermediate tank 8 through the flow path 7, it is supplied to the 23 kPa low boiling cut tower 10 at 130 parts / hr. The low boiling point was distilled off in the flow path 11. The low boiling point could be reused for the alkenylation reaction. The column bottom liquid is extracted through the flow path 12, and the high boiling point is 8 parts / hr. While extracting, 10 parts / hr. Of 5-phenyl-2-hexene is transferred from the flow path 15 to the intermediate tank 16. Extracted.

(B) Cyclization / dehydrogenation step The same catalyst as in the Reference Example was charged into the cyclization reactor 18, and under normal pressure, the reaction temperature was 170 ° C, and 5-phenyl-2-hexene was added from the intermediate tank 16 to 10 parts / hr. And at a rate of 250 parts nitrogen / min. The cyclization reaction was carried out. The molar ratio of the diluent to the raw material was 11. After the cyclization reaction, the dehydrogenation reactor 20 filled with 40 parts of 1% platinum / activated carbon catalyst (manufactured by NE Chemcat) was continuously supplied from the flow path 19. The reaction temperature was 280 ° C. As a diluting solvent, heptane is 20 parts / hr. The dehydrogenation reaction was carried out while simultaneously supplying the same. After the reaction, the solvent was supplied from the flow path 21 to the solvent recovery tower 22 decompressed to 19 kPa, and heptane was recovered from the flow path 23. After heptane recovery, the low boiling point is supplied from the flow path 24 to the low boiling high boiling cut tower 25 which has been depressurized to 13 kPa. The high boiling point is 0.3 parts / hr. 9.4 parts of 1,4-DMN having a purity of 98% were extracted from the middle stage of the tower from the flow path 28 and extracted to the intermediate tank 41 by omitting the isomerization step.

(D) Oxidation step To a titanium oxidation reactor 45 equipped with a gas discharge pipe with a reflux condenser, a gas introduction pipe, and a stirrer, 1,4-DMN was added from an intermediate tank 41 to 3 parts / hr. Was supplied by the flow path 42. At the same time, the flow path 43 was used to add 36 parts / hr. Of 95% aqueous acetic acid having a Br ion concentration of 1600 ppm, a manganese concentration of 500 ppm, and a cobalt concentration of 400 ppm. Supplied. The amount of air supplied from the channel 44 was adjusted so that the oxygen concentration of the Off gas in the channel 46 was 1 to 5%. The reaction pressure was 1 MPa and the temperature was 170 ° C. A part of the return of the reflux was extracted from the channel 47, and a part of the oxidation reaction water was continuously extracted. The reaction solution was continuously withdrawn into the intermediate tank 49 at normal pressure through the channel 48 so that the amount of solution in the oxidation reactor was constant at 70 parts. The oxidation reaction liquid was supplied from the flow path 50 by the solid-liquid separator 51, and the separated cake was supplied from the flow path 52 to the dryer 54 to recover acetic acid. Part or all of the separated mother liquor obtained from the flow path 53 can be recycled to the oxidation reactor 45 by adjusting the catalyst concentration and water concentration.
The dried crystals are 95% 1,4-NDCA and 2.5 parts / hr. Thus, the intermediate silo 56 is continuously filled from the flow path 55.

(E) Esterification Step From the intermediate silo 56, 36 parts of crystals were supplied to the esterification reactor 58 through the flow path 57, and simultaneously 70 parts of methanol and 3.6 parts of sulfuric acid were supplied. The esterification reactor was heated to 130 ° C. and 1.3 MPa, the pressure was increased, and 2 hr. The batch reaction was performed with stirring. The yield of 1,4-NDCM was 99.8%. After completion of the reaction, the reaction solution was transferred to the crystallization tank 61 through the channel 60 and cooled to 30 ° C. to precipitate a solid. The obtained slurry was passed through the flow path 62 at 10 parts / hr. To the solid-liquid separator 63. The separated cake was supplied to the dryer 66 through the flow path 64 to recover the attached methanol. The separation mother liquor in the channel 65 was discarded after the methanol was recovered. The dried crystals were 3.8 parts / hr. Was supplied to a distillation column 68 which was dissolved and depressurized to 2 kPa through a channel 67. In the distillation tower 68, the high boiling point is 0.2 parts / hr. 1,4-NDCM was extracted from the flow path 70. 1,4-NDCM of the flow path 70 is added to the dissolution tank 71 at 10 parts / hr. Of toluene. It was supplied at the same time. In the dissolution tank 71, 1,4-NDCM was completely dissolved under conditions of normal pressure and 100 ° C. This solution was supplied to the crystallization tank 73 through the flow path 72 and cooled to a temperature of 0 ° C. to crystallize 1,4-NDCM. The slurry liquid after crystallization was supplied from the flow path 74 to the solid-liquid separator 75, the cake was separated and rinsed, and then supplied to the dryer 78 from the flow path 76 to collect toluene. The separated mother liquor obtained from the flow path 77 was recycled to the distillation column 68 after toluene was recovered. The dried 1,4-NDCM was supplied to the distillation column 80 which was melted and reduced in pressure to 2 kPa from the flow path 79. High boiling point from the channel 81 is 0.05 parts / hr. Extracted. This high boiling point could be recycled to the distillation column 68. From the flow channel 82, 2.8 parts / hr. Extracted 1,4-NDCM having a purity of 99.5%.

<Example 2 (Production of 2,3-NDCM)>
The same procedure as in Example 1 was performed until the cyclization / dehydrogenation step.

(C) Isomerization process The catalyst 20 parts similar to the reference example was charged into the isomerization reactor 31. 1,4-DMN in the intermediate tank 29 from the flow path 30 and 9.4 parts / hr. From the lower part of the isomerization reactor. The isomerization reaction was carried out at 255 ° C. under normal pressure. The reaction product solution is supplied from the flow path 32 to the crystallization tank 33 and diluted with heptane 5 parts / hr. In addition, 2,3-DMN was precipitated by being cooled to 25 ° C. in the crystallization tank 33. The slurry liquid was supplied to the solid-liquid separator 35 through the flow path 34, and filtered and rinsed. The separated mother liquor contained 7 parts of a mixture of DMN isomers. The flow path 36 can be recycled to the solvent recovery tower 22. The crystal after rinsing was heated and dissolved from the flow path 37 and then supplied to the low boiling cut tower 38 decompressed to 19 kPa. One part of low boiling point is extracted by the flow path 39, and 2,3-DMN having a purity of 99% is extracted from the flow path 40 by 2 parts / hr. Was extracted and supplied to the intermediate tank 41.

(D) Oxidation step To a titanium oxidation reactor 45 equipped with a gas discharge pipe with a reflux condenser, a gas introduction pipe, and a stirrer, 2,3-DMN from the intermediate tank 41 is 3 parts / hr. Was supplied by the flow path 42. At the same time, the flow path 43 was used to add 36 parts / hr. Of 90% aqueous acetic acid having a Br ion concentration of 1600 ppm, a manganese concentration of 500 ppm, and a cobalt concentration of 1000 ppm. Supplied with. The amount of air supplied from the channel 44 was adjusted so that the oxygen concentration of the Off gas in the channel 46 was 1 to 5%. The reaction pressure was 1.0 MPa and the temperature was 170 ° C. A part of the return of the reflux was extracted from the channel 47, and a part of the oxidation reaction water was continuously extracted. The reaction solution was continuously withdrawn into the intermediate tank 49 at normal pressure through the channel 48 so that the amount of solution in the oxidation reactor was constant at 70 parts. The oxidation reaction liquid was supplied from the flow path 50 by the solid-liquid separator 51, and the separated cake was supplied from the flow path 52 to the dryer 54 to recover acetic acid. Part or all of the separated mother liquor obtained from the flow path 53 can be recycled to the oxidation reactor 45 by adjusting the catalyst concentration and water concentration.
The dried crystals are 95% 2,3-NDCA, 2.4 parts / hr. Thus, the intermediate silo 56 is continuously filled from the flow path 55.

(E) Esterification Step From the intermediate silo 56, 36 parts of crystals were supplied to the esterification reactor 58 through the flow path 57, and simultaneously 70 parts of methanol and 3.6 parts of sulfuric acid were supplied. The esterification reactor was heated to 130 ° C. and 1.3 MPa, the pressure was increased, and 2 hr. The batch reaction was performed with stirring. The yield of 2,3-NDCM was 99.8%. After completion of the reaction, the reaction solution was transferred to the crystallization tank 61 through the channel 60 and cooled to 30 ° C. to precipitate a solid. The obtained slurry was passed through the flow path 62 at 10 parts / hr. To the solid-liquid separator 63. The separated cake was supplied to the dryer 66 through the flow path 64 to recover the attached methanol. The separation mother liquor in the channel 65 was discarded after the methanol was recovered. The dried crystals were 3.8 parts / hr. Was supplied to a distillation column 68 which was dissolved and depressurized to 2 kPa through a channel 67. In the distillation tower 68, the high boiling point is 0.2 parts / hr. 2,3-NDCM was extracted from the flow path 70. 2,3-NDCM of the flow path 70 is added to the dissolution tank 71 at a rate of 10 parts toluene / hr. At the same time supplied. In the dissolution tank 71, 2,3-NDCM was completely dissolved under conditions of normal pressure and 100 ° C. This solution was supplied to the crystallization tank 73 through the flow path 72, cooled to 0 ° C., and 2,3-NDCM was crystallized. The slurry liquid after crystallization was supplied from the flow path 74 to the solid-liquid separator 75, the cake was separated and rinsed, and then supplied to the dryer 78 from the flow path 76 to collect toluene. The separated mother liquor obtained from the flow path 77 was recycled to the distillation column 68 after toluene was recovered. The dried 2,3-NDCM was supplied to the distillation column 80 which was melted and reduced in pressure to 2 kPa from the flow path 79. High boiling point from the channel 81 is 0.05 parts / hr. Extracted. This high boiling point could be recycled to the distillation column 68. From the flow channel 82, 2.8 parts / hr. Extracted 2,3-NDCM having a purity of 99.5%.

<Example 3 (Production of 1,7-NDCM)>
The same apparatus was used according to the reference example except that the raw material ortho-xylene was changed to para-xylene.

(A) 10 parts of the same catalyst as in the alkenylation reference example was supplied to the alkenylation reactor 3, stirred at 180 ° C. in a nitrogen atmosphere, 0.5 parts of sodium metal was added thereto, and then at that temperature for 60 minutes. Stir. 1000 parts of para-xylene were fed to the alkenylation reactor 3 and heated to 140 ° C. While vigorously stirring, 70 parts of 1,3-butadiene was introduced in 1 hour to carry out a batch reaction. After completion of the reaction, the reaction mixture was cooled, transferred to the catalyst decomposition tank 5 from the flow path 4, and 50 parts of 10% aqueous sulfuric acid solution was supplied from the flow path 6 while stirring. The yield of para-xylene reacted with 5-paratoluyl-2-pentene was 82%. After the upper layer is transferred to the intermediate tank 8 through the flow path 7, it is transferred to the 23 kPa low boiling cut tower 10 at 63 parts / hr. The low boiling point was distilled off in the flow path 11. The low boiling point could be reused for the alkenylation reaction. The column bottom liquid is extracted through the flow path 12, and the high boiling point is 2 parts / hr. 10-hr / hr. Of 5-paratoluyl-2-pentene from the flow path 15 to the intermediate tank 16. Extracted.

(B) Cyclization / dehydrogenation step The same catalyst as in the reference example was charged into the cyclization reactor 18, and under normal pressure, the reaction temperature was 170 ° C, and 5-paratoluyl-2-pentene was added from the intermediate tank 16 to 10 parts / hr. And at a rate of 250 parts nitrogen / min. The cyclization reaction was carried out. The molar ratio of the diluent to the raw material was 11. After the cyclization reaction, the dehydrogenation reactor 20 filled with 40 parts of 1% platinum / activated carbon catalyst (manufactured by NE Chemcat) was continuously supplied from the flow path 19. The reaction temperature was 280 ° C. As a diluting solvent, heptane is 20 parts / hr. The dehydrogenation reaction was carried out while supplying them simultaneously. After the reaction, the solvent was supplied from the flow path 21 to the solvent recovery tower 22 decompressed to 19 kPa, and heptane was recovered from the flow path 23. After heptane recovery, the low boiling point is supplied from the flow path 24 to the low boiling high boiling cut tower 25 which has been depressurized to 13 kPa. The high boiling point is 0.3 parts / hr. And 9.4 parts of 98% pure 1,7-DMN were extracted from the middle stage of the tower through the flow path 28 to the intermediate tank 41.

(D) Oxidation step To a titanium oxidation reactor 45 equipped with a gas discharge pipe with a reflux condenser, a gas introduction pipe, and a stirrer, 1,7-DMN from an intermediate tank 41 is 3 parts / hr. Was supplied by the flow path 42. At the same time, the flow path 43 was used to add 95 parts hydrous acetic acid having a Br ion concentration of 1600 ppm, a manganese concentration of 2000 ppm, and a cobalt concentration of 800 ppm to 36 parts / hr. Supplied. The amount of air supplied from the channel 44 was adjusted so that the oxygen concentration of the Off gas in the channel 46 was 1 to 5%. The reaction pressure was 1.8 MPa, and the temperature was 200 ° C. A part of the return of the reflux was extracted from the channel 47, and a part of the oxidation reaction water was continuously extracted. The reaction solution was continuously withdrawn into the intermediate tank 49 at normal pressure through the channel 48 so that the amount of solution in the oxidation reactor was constant at 70 parts. The oxidation reaction liquid was supplied from the flow path 50 by the solid-liquid separator 51, and the separated cake was supplied from the flow path 52 to the dryer 54 to recover acetic acid. Part or all of the separated mother liquor obtained from the flow path 53 can be recycled to the oxidation reactor 45 by adjusting the catalyst concentration and water concentration.
The dried crystals are 97% 1,7-NDCA, 3.2 parts / hr. Thus, the intermediate silo 56 is continuously filled from the flow path 55.

(E) Esterification Step From the intermediate silo 56, 36 parts of crystals were supplied to the esterification reactor 58 through the flow path 57, and 360 parts of methanol and 3.6 parts of sulfuric acid were simultaneously supplied. The esterification reactor was heated to 130 ° C. and 1.3 MPa, and the pressure was increased for 3 hours. The batch reaction was performed with stirring. The yield of 1,7-NDCM was 99.8%. After completion of the reaction, the reaction solution was transferred to the crystallization tank 61 through the channel 60 and cooled to 30 ° C. to precipitate a solid. The obtained slurry was fed at 36 parts / hr. To the solid-liquid separator 63. The separated cake was supplied to the dryer 66 through the flow path 64 to recover the attached methanol. The separation mother liquor in the channel 65 was discarded after the methanol was recovered. The dried crystals were 3.8 parts / hr. Was supplied to a distillation column 68 which was dissolved and depressurized to 2 kPa through a channel 67. In the distillation tower 68, the high boiling point is 0.2 parts / hr. 1,7-NDCM was extracted from the flow path 70. 1,7-NDCM in the flow path 70 was added to the dissolution tank 71 at 10 parts / hr. At the same time supplied. In the dissolution tank 71, 1,7-NDCM was completely dissolved under conditions of normal pressure and 130 ° C. This solution was supplied to the crystallization tank 73 through the flow path 72 and cooled to a temperature of 30 ° C. to crystallize 1,7-NDCM. The slurry liquid after crystallization was supplied to the solid-liquid separator 75 from the flow path 74, separated and rinsed, and then supplied to the dryer 78 from the flow path 76 to recover metaxylene. The separated mother liquor obtained from the flow path 77 was recycled to the distillation column 68 after recovering meta-xylene. The dried 1,7-NDCM was supplied to the distillation tower 80 which was dissolved and reduced in pressure to 2 kPa from the flow path 79. High boiling point from the channel 81 is 0.05 parts / hr. Extracted. This high boiling point could be recycled to the distillation column 68. From the flow channel 82, 3.5 parts / hr. Extracted 1,7-NDCM having a purity of 99.5%.

<Example 4 (Production of 2,7-NDCM)>
The same procedures as in Example 3 were performed until the cyclization / dehydrogenation step.

(C) Isomerization process The catalyst 20 parts similar to the reference example was charged into the isomerization reactor 31. 1,7-DMN in the intermediate tank 29 from the flow path 30 and 9.4 parts / hr. From the lower part of the isomerization reactor. The isomerization reaction was carried out at 255 ° C. under normal pressure. The reaction product solution is supplied from the flow path 32 to the crystallization tank 33 and diluted with heptane 5 parts / hr. Then, 2,7-DMN was precipitated by cooling to 25 ° C. in the crystallization tank 33. The slurry liquid was supplied to the solid-liquid separator 35 through the flow path 34, and filtered and rinsed. The separated mother liquor contained 6.5 parts of a mixture of DMN isomers. The flow path 36 can be recycled to the solvent recovery tower 22. The crystal after rinsing was heated and dissolved from the flow path 37 and then supplied to the low boiling cut tower 38 decompressed to 19 kPa. One part of low boiling point is extracted by the flow path 39, and 2,7-DMN having a purity of 99% is extracted from the flow path 40 by 2.5 parts / hr. Was extracted and supplied to the intermediate tank 41.

(D) Oxidation step To a titanium oxidation reactor 45 equipped with a gas discharge pipe with a reflux condenser, a gas introduction pipe, and a stirrer, 2,7-DMN was added 3 parts / hr. Was supplied by the flow path 42. At the same time, the flow path 43 was used to add 36 parts / hr. Of 95% aqueous acetic acid having a Br ion concentration of 1600 ppm, a manganese concentration of 500 ppm, and a cobalt concentration of 2000 ppm. Supplied. The amount of air supplied from the channel 44 was adjusted so that the oxygen concentration of the Off gas in the channel 46 was 1 to 5%. The reaction pressure was 1.8 MPa, and the temperature was 200 ° C. A part of the return of the reflux was extracted from the channel 47, and a part of the oxidation reaction water was continuously extracted. The reaction solution was continuously withdrawn into the intermediate tank 49 at normal pressure through the channel 48 so that the amount of solution in the oxidation reactor was constant at 70 parts. The oxidation reaction liquid was supplied from the flow path 50 by the solid-liquid separator 51, and the separated cake was supplied from the flow path 52 to the dryer 54 to recover acetic acid. Part or all of the separated mother liquor obtained from the flow path 53 can be recycled to the oxidation reactor 45 by adjusting the catalyst concentration and water concentration.
The dried crystals are 97% 2,7-NDCA, 3.2 parts / hr. Thus, the intermediate silo 56 is continuously filled from the flow path 55.

(E) Esterification Step From the intermediate silo 56, 36 parts of crystals were supplied to the esterification reactor 58 through the flow path 57, and 360 parts of methanol and 3.6 parts of sulfuric acid were simultaneously supplied. The esterification reactor was heated to 130 ° C. and 1.3 MPa, and the pressure was increased for 3 hours. The batch reaction was performed with stirring. The yield of 2,7-NDCM was 99.8%. After completion of the reaction, the reaction solution was transferred to the crystallization tank 61 through the channel 60 and cooled to 30 ° C. to precipitate a solid. The obtained slurry was fed at 36 parts / hr. To the solid-liquid separator 63. The separated cake was supplied to the dryer 66 through the flow path 64 to recover the attached methanol. The separation mother liquor in the channel 65 was discarded after the methanol was recovered. The dried crystals were 3.8 parts / hr. Was supplied to a distillation column 68 which was dissolved and depressurized to 2 kPa through a channel 67. In the distillation tower 68, the high boiling point is 0.2 parts / hr. 2,7-NDCM was extracted from the flow path 70. 2,7-NDCM in the flow path 70 is added to the dissolution tank 71 at 10 parts / hr. At the same time supplied. In the dissolution tank 71, 2,7-NDCM was completely dissolved under conditions of normal pressure and 130 ° C. This solution was supplied to the crystallization tank 73 through the channel 72 and cooled to a temperature of 30 ° C. to crystallize 2,7-NDCM. The slurry liquid after crystallization was supplied to the solid-liquid separator 75 from the flow path 74, separated and rinsed, and then supplied to the dryer 78 from the flow path 76 to recover metaxylene. The separated mother liquor obtained from the flow path 77 was recycled to the distillation column 68 after recovering meta-xylene. The dried 2,7-NDCM was supplied to the distillation column 80 which was dissolved and reduced in pressure to 2 kPa from the flow path 79. High boiling point from the channel 81 is 0.05 parts / hr. Extracted. This high boiling point could be recycled to the distillation column 68. From the flow channel 82, 3.5 parts / hr. Extracted 99.5% pure 2,7-NDCM.

<Example 5 (Production of 1,2-NDCM)>
The same apparatus was used according to the reference example except that the raw material was changed from orthoxylene to toluene and butadiene to isoprene.

(A) The catalyst treated in the same manner as in the alkenylation reference example and 1200 parts of toluene were supplied to the alkenylation reactor 3 and heated to 130 ° C. While vigorously stirring, 80 parts of isoprene were introduced in 1 hour to carry out a batch reaction. After completion of the reaction, the reaction mixture was cooled, transferred to the catalyst decomposition tank 5 from the flow path 4, and 50 parts of 10% aqueous sulfuric acid solution was supplied from the flow path 6 while stirring. The yield per ethylbenzene reacted with 3-methyl-5-phenyl-2-pentene was 70%. After the upper layer was transferred to the intermediate tank 8 by the flow path 7, it was transferred to the low-boiling cut tower 10 of 23 kPa at 100 parts / hr. The low boiling point was distilled off in the flow path 11. The low boiling point could be reused for the alkenylation reaction. The liquid at the bottom of the column is extracted through the flow path 12, and the high boiling point is 4 parts / hr. While being extracted, 3-methyl-5-phenyl-2-pentene was transferred from the flow path 15 to the intermediate tank 16 at 10 parts / hr. Extracted.

(B) Cyclization / dehydrogenation step The same catalyst as in the reference example was charged into the cyclization reactor 18, and under normal pressure, the reaction temperature was 170 ° C, and 10 parts of 3-methyl-5-phenyl-2-pentene was added from the intermediate tank 16. / Hr. And at a rate of 250 parts nitrogen / min. The cyclization reaction was carried out. The molar ratio of the diluent to the raw material was 11. After the cyclization reaction, the dehydrogenation reactor 20 filled with 40 parts of 1% platinum / activated carbon catalyst (manufactured by NE Chemcat) was continuously supplied from the flow path 19. The reaction temperature was 280 ° C. As a diluting solvent, heptane is 20 parts / hr. The dehydrogenation reaction was carried out while simultaneously supplying the same. After the reaction, the solvent was supplied from the flow path 21 to the solvent recovery tower 22 decompressed to 19 kPa, and heptane was recovered from the flow path 23. After heptane recovery, the low boiling point is supplied from the flow path 24 to the low boiling high boiling cut tower 25 which has been depressurized to 13 kPa. The high boiling point is 0.3 parts / hr. Then, 9.4 parts of 1,2-DMN having a purity of 98% were extracted from the middle stage of the column from the flow path 28, and extracted to the intermediate tank 41 by omitting the isomerization step.

(D) Oxidation step To a titanium oxidation reactor 45 equipped with a gas discharge pipe with a reflux condenser, a gas introduction pipe, and a stirrer, 1,2-DMN from the intermediate tank 41 is 3 parts / hr. Was supplied by the flow path 42. At the same time, the flow path 43 was used to add 36 parts / hr. Of 90% aqueous acetic acid having a Br ion concentration of 1600 ppm, a manganese concentration of 500 ppm, and a cobalt concentration of 1000 ppm. Supplied. The amount of air supplied from the channel 44 was adjusted so that the oxygen concentration of the Off gas in the channel 46 was 1 to 5%. The reaction pressure was 1 MPa and the temperature was 170 ° C. A part of the return of the reflux was extracted from the channel 47, and a part of the oxidation reaction water was continuously extracted. The reaction solution was continuously withdrawn into the intermediate tank 49 at normal pressure through the channel 48 so that the amount of solution in the oxidation reactor was constant at 70 parts. The oxidation reaction liquid was supplied from the flow path 50 by the solid-liquid separator 51, and the separated cake was supplied from the flow path 52 to the dryer 54 to recover acetic acid. Part or all of the separated mother liquor obtained from the flow path 53 can be recycled to the oxidation reactor 45 by adjusting the catalyst concentration and water concentration.
The dried crystals are 95% 1,2-NDCA, 2.5 parts / hr. Thus, the intermediate silo 56 is continuously filled from the flow path 55.

(E) Esterification Step From the intermediate silo 56, 36 parts of crystals were supplied to the esterification reactor 58 through the flow path 57, and simultaneously 70 parts of methanol and 3.6 parts of sulfuric acid were supplied. The temperature of the esterification reactor was increased to 130 ° C. and 1.3 MPa, and the pressure was increased. The batch reaction was performed with stirring. The yield of 1,2-NDCM was 99.8%. After completion of the reaction, the reaction solution was transferred to the crystallization tank 61 through the channel 60 and cooled to 30 ° C. to precipitate a solid. The obtained slurry was passed through the flow path 62 at 10 parts / hr. To the solid-liquid separator 63. The separated cake was supplied to the dryer 66 through the flow path 64 to recover the attached methanol. The separation mother liquor in the channel 65 was discarded after the methanol was recovered. The dried crystals were 3.8 parts / hr. Was supplied to a distillation column 68 which was dissolved and depressurized to 2 kPa through a channel 67. In the distillation tower 68, the high boiling point is 0.2 parts / hr. 1,2-NDCM was extracted from the flow path 70. 1,2-NDCM of the flow path 70 is added to the dissolution tank 71 at 10 parts / hr. Of toluene. At the same time supplied. In the dissolution tank 71, 1,2-NDCM was completely dissolved under conditions of normal pressure and 100 ° C. This solution was supplied to the crystallization tank 73 through the channel 72 and cooled to a temperature of 0 ° C. to crystallize 1,2-NDCM. The slurry liquid after crystallization was supplied from the flow path 74 to the solid-liquid separator 75, the cake was separated and rinsed, and then supplied to the dryer 78 from the flow path 76 to collect toluene. The separated mother liquor obtained from the flow path 77 was recycled to the distillation column 68 after toluene was recovered. The dried 1,2-NDCM was supplied to the distillation column 80 which was melted and reduced in pressure to 2 kPa from the flow path 79. High boiling point from the channel 81 is 0.05 parts / hr. Extracted. This high boiling point could be recycled to the distillation column 68. From the flow channel 82, 2.8 parts / hr. Extracted 99.5% pure 1,2-NDCM.

<Example 6 (Production of 1,6-NDCM)>
The same apparatus was used according to the reference example except that the raw material ortho-xylene was changed to meta-xylene.

(A) 10 parts of the same catalyst as in the alkenylation reference example was supplied to the alkenylation reactor 3, stirred at 180 ° C. in a nitrogen atmosphere, 0.5 parts of sodium metal was added thereto, and then at that temperature for 60 minutes. Stir. 1000 parts of metaxylene were fed to the alkenylation reactor 3 and heated to 140 ° C. While stirring vigorously, 70 parts of 1,3-butadiene was added for 1 hr. Introduced in to batch reaction. After completion of the reaction, the reaction mixture was cooled, transferred to the catalyst decomposition tank 5 from the flow path 4, and 50 parts of 10% aqueous sulfuric acid solution was supplied from the flow path 6 while stirring. The yield per meta-xylene reacted with 5-metatoluyl-2-pentene was 81%. After the upper layer is transferred to the intermediate tank 8 through the flow path 7, it is transferred to the 23 kPa low boiling cut tower 10 at 63 parts / hr. The low boiling point was distilled off in the flow path 11. The low boiling point could be reused for the alkenylation reaction. The column bottom liquid is extracted through the flow path 12, and the high boiling point is 2 parts / hr. The 5-metatoluyl-2-pentene was extracted from the flow path 15 into the intermediate tank 16 at 10 parts / h. Extracted.

(B) Cyclization / dehydrogenation step The same catalyst as in the reference example was charged into the cyclization reactor 18, and under normal pressure, the reaction temperature was 170 ° C, and 5-metatoluyl-2-pentene was added from the intermediate tank 16 to 10 parts / hr. And at a rate of 250 parts nitrogen / min. The cyclization reaction was carried out. The molar ratio of the diluent to the raw material was 11. After the cyclization reaction, the dehydrogenation reactor 20 filled with 40 parts of 1% platinum / activated carbon catalyst (manufactured by NE Chemcat) was continuously supplied from the flow path 19. The reaction temperature was 280 ° C. As a diluting solvent, heptane is 20 parts / hr. The dehydrogenation reaction was carried out while simultaneously supplying the same. After the reaction, the solvent was supplied from the flow path 21 to the solvent recovery tower 22 decompressed to 19 kPa, and heptane was recovered from the flow path 23. After heptane recovery, the low boiling point is supplied from the flow path 24 to the low boiling high boiling cut tower 25 which has been depressurized to 13 kPa. The high boiling point is 5.3 parts / hr. Then, 1,6-DMN having a purity of 95% was extracted from the middle stage of the column into the intermediate tank 41 by 4.5 parts from the flow path 28.

(D) Oxidation step To a titanium oxidation reactor 45 equipped with a gas discharge pipe with a reflux condenser, a gas introduction pipe, and a stirrer, 1,6-DMN was added 3 parts / hr. Was supplied by the flow path 42. At the same time, the flow path 43 was used to add 36 parts / hr. Of 95% aqueous acetic acid having a Br ion concentration of 1600 ppm, a manganese concentration of 2500 ppm, and a cobalt concentration of 400 ppm. Supplied. The amount of air supplied from the channel 44 was adjusted so that the oxygen concentration of the Off gas in the channel 46 was 1 to 5%. The reaction pressure was 1.8 MPa, and the temperature was 200 ° C. A part of the return of the reflux was extracted from the channel 47, and a part of the oxidation reaction water was continuously extracted. The reaction solution was continuously withdrawn into the intermediate tank 49 at normal pressure through the channel 48 so that the amount of solution in the oxidation reactor was constant at 70 parts. The oxidation reaction liquid was supplied from the flow path 50 by the solid-liquid separator 51, and the separated cake was supplied from the flow path 52 to the dryer 54 to recover acetic acid. Part or all of the separated mother liquor obtained from the flow path 53 can be recycled to the oxidation reactor 45 by adjusting the catalyst concentration and water concentration.
The dried crystals are 97% 1,6-NDCA, 2.7 parts / hr. Thus, the intermediate silo 56 is continuously filled from the flow path 55.

(E) Esterification Step From the intermediate silo 56, 36 parts of crystals were supplied to the esterification reactor 58 through the flow path 57, and 360 parts of methanol and 3.6 parts of sulfuric acid were simultaneously supplied. The esterification reactor was heated to 130 ° C. and 1.3 MPa, and the pressure was increased for 3 hours. The batch reaction was performed with stirring. The yield of 1,6-NDCM was 99.8%. After completion of the reaction, the reaction solution was transferred to the crystallization tank 61 through the channel 60 and cooled to 30 ° C. to precipitate a solid. The obtained slurry was fed at 36 parts / hr. To the solid-liquid separator 63. The separated cake was supplied to the dryer 66 through the flow path 64 to recover the attached methanol. The separation mother liquor in the channel 65 was discarded after the methanol was recovered. The dried crystals were 3.8 parts / hr. Was supplied to a distillation column 68 which was dissolved and depressurized to 2 kPa through a channel 67. In the distillation tower 68, the high boiling point is 0.2 parts / hr. 1,6-NDCM was extracted from the flow path 70. 1,6-NDCM in the flow path 70 was added to the dissolution tank 71 at 10 parts / hr. At the same time supplied. In the dissolution tank 71, 1,6-NDCM was completely dissolved under conditions of normal pressure and 130 ° C. This solution was supplied to the crystallization tank 73 through the flow path 72 and cooled to a temperature of 30 ° C. to crystallize 1,6-NDCM. The slurry liquid after crystallization was supplied to the solid-liquid separator 75 from the flow path 74, separated and rinsed, and then supplied to the dryer 78 from the flow path 76 to recover metaxylene. The separated mother liquor obtained from the flow path 77 was recycled to the distillation column 68 after recovering meta-xylene. The dried 1,6-NDCM was supplied to the distillation column 80 which was dissolved and reduced in pressure to 2 kPa from the flow path 79. High boiling point from the channel 81 is 0.05 parts / hr. Extracted. This high boiling point could be recycled to the distillation column 68. From the flow channel 82, 3.5 parts / hr. Extracted 1,6-NDCM having a purity of 99.5%.

(A) Example of process flow of alkenylation step. (B) Example of process flow of cyclization / dehydrogenation step. (C) Example of process flow of isomerization step. (D) Example of process flow of oxidation process. (E) Example of process flow of esterification step.

Explanation of symbols

3: Alkenylation reactor 5: Catalyst decomposition tank 8: Intermediate tank 10: Low boiling cut tower 13: High boiling cut tower 16: Intermediate tank 18: Cyclization reactor 20: Dehydrogenation reactor 22: Solvent recovery tower 25: Low boiling high boiling cut tower 29: Intermediate tank 31: Isomerization reactor 33: Crystallization tank 35: Solid-liquid separator 38: Low boiling cut tower 41: Intermediate tank 45: Oxidation reactor 49: Solid-liquid separator 51: Intermediate tank 54: Dryer 56: Intermediate silo 58: Esterification reactor 61: Crystallization tank 63: Solid-liquid separator 66: Dryer 68: Distillation tower 71: Dissolution tank 73: Crystallization tank 75: Solid-liquid separator 78 : Dryer 80: Distillation tower

Claims (25)

Using a manufacturing apparatus that operates according to a manufacturing method comprising the following steps (a), (b), (c), (d) and (e), or (a), (b), (d) and (e) A method for producing dimethyl naphthalenedicarboxylate, comprising producing two or more isomers of dimethyl naphthalenedicarboxylate by changing the combination of the aromatic hydrocarbon and the diene as raw materials.
(A) An alkenylation step for producing an alkenylated product from an aromatic hydrocarbon and a diene. (B) A ring for producing dimethylnaphthalene by producing dimethyltetralin by cyclization of the alkenylated product and then dehydrogenating dimethyltetralin. (C) Dimethylnaphthalene isomerization step (d) Dimethylnaphthalene is oxidized to produce naphthalene dicarboxylic acid (e) Naphthalene dicarboxylic acid is esterified in the presence of methanol to form naphthalene dicarboxylic acid Esterification process to produce dimethyl acid The isomers of dimethyl naphthalenedicarboxylate are from 1,2-, 1,4-, 1,5-, 1,6-, 1,7-, 2,3-, 2,6- and 2,7-isomers. The method for producing dimethyl naphthalenedicarboxylate according to claim 1, which is selected. The isomer of dimethyl naphthalenedicarboxylate is at least one selected from 1,2-, 1,4-, 1,6-, 1,7-, 2,3- and 2,7-isomers. A process for producing dimethyl naphthalenedicarboxylate according to 1. The method for producing dimethyl naphthalenedicarboxylate according to claim 1, wherein the aromatic hydrocarbon as a raw material is selected from toluene, ortho-xylene, para-xylene, meta-xylene and ethylbenzene. The method for producing dimethyl naphthalenedicarboxylate according to claim 1, wherein the starting diene is selected from 1,3-butadiene and isoprene. The method for producing dimethyl naphthalenedicarboxylate according to claim 1, wherein the production apparatus is an apparatus for producing dimethyl 2,6-naphthalenedicarboxylate. Aromatic hydrocarbons and dienes are started by the following steps (a), (b), (c), (d) and (e), or (a), (b), (d) and (e) Dimethyl naphthalenedicarboxylate characterized by producing an isomer selected from 1,2-, 1,4-, 1,6-, 1,7-, 2,3- and 2,7-isomers as a raw material Manufacturing method.
(A) An alkenylation step for producing an alkenylated product from an aromatic hydrocarbon and a diene. (B) A ring for producing dimethylnaphthalene by producing dimethyltetralin by cyclization of the alkenylated product and then dehydrogenating dimethyltetralin. (C) Dimethylnaphthalene isomerization step (d) Dimethylnaphthalene is oxidized to produce naphthalene dicarboxylic acid (e) Naphthalene dicarboxylic acid is esterified in the presence of methanol to form naphthalene dicarboxylic acid Esterification process to produce dimethyl acid The method for producing dimethyl naphthalenedicarboxylate according to claim 7, wherein 1,4-isomer and / or 2,3-isomer is produced using ethylbenzene and 1,3-butadiene as starting materials. The method for producing dimethyl naphthalenedicarboxylate according to claim 7, wherein 1,7-isomer and / or 2,7-isomer is produced using paraxylene and 1,3-butadiene as starting materials. The process for producing dimethyl naphthalenedicarboxylate according to claim 7, wherein 1,2-isomers are produced using toluene and isoprene as starting materials. The method for producing dimethyl naphthalenedicarboxylate according to claim 7, wherein 1,6-isomer is produced using meta-xylene and 1,3-butadiene as starting materials. (B) In the cyclization / dehydrogenation step, among the 1,6- and 1,8-dimethyltetralin mixtures produced by cyclization, only the 1,6-isomer was dehydrogenated to give 1,6-dimethylnaphthalene. The method for producing dimethyl naphthalenedicarboxylate according to claim 11, which is then subjected to (d) an oxidation step after being separated from other components by distillation. The method for producing dimethyl naphthalenedicarboxylate according to any one of claims 1 to 12, wherein in the (a) alkenylation step, metal potassium and / or a mixture of potassium compound and metal sodium and / or sodium compound is used as a catalyst. The method for producing dimethyl naphthalenedicarboxylate according to any one of claims 1 to 13, wherein in the (b) cyclization / dehydrogenation step, the alkenyl compound is cyclized using a solid acid catalyst as a catalyst. (B) In the cyclization / dehydrogenation step, the dehydrogenation reaction is performed in the presence of a supported noble metal catalyst at a temperature of about 150 to 250 ° C. and a pressure of about 0.03 to 0.5 MPa. The manufacturing method of dimethyl naphthalenedicarboxylate in any one of -14. (C) The method for producing dimethyl naphthalenedicarboxylate according to any one of claims 1 to 15, wherein a solid catalyst containing alumina and / or silica is used in the isomerization step. (D) The dimethyl naphthalenedicarboxylate according to any one of claims 1 to 16, wherein the oxidation step is liquid phase oxidation performed in the presence of a catalyst containing cobalt, manganese and bromine in the presence of a solvent containing a monocarboxylic acid. Manufacturing method. (E) the esterification step is carried out by heating a mixture of methanol and naphthalenedicarboxylic acid at a pressure between about 0.1 and 1.5 MPa to a temperature between about 60 and 200 ° C., and The method for producing dimethyl naphthalenedicarboxylate according to any one of claims 1 to 17, wherein the pressure is selected so as to maintain at least a part of methanol in a liquid phase. (B) The method for producing dimethyl naphthalenedicarboxylate according to any one of claims 1 to 18, comprising a step of recrystallizing dimethylnaphthalene produced in the cyclization / dehydrogenation step. The method for producing dimethyl naphthalenedicarboxylate according to any one of claims 1 to 19, further comprising a step of distilling and purifying dimethyltetralin to a purity of at least 95 wt% before dehydrogenation in the cyclization / dehydrogenation step. . The method for producing dimethyl naphthalenedicarboxylate according to any one of claims 1 to 20, wherein crystallization is carried out after isomerization, and only dimethylnaphthalene having the highest melting point in the existing isomers is crystallized. At least dimethyl naphthalene dicarboxylate obtained by the production method according to claim 1 and / or naphthalene dicarboxylate and / or naphthalene carboxylate derived from naphthalene dicarboxylic acid obtained as an intermediate in the production method One polymer. 23. A fiber comprising the polymer of claim 22. 23. A film comprising the polymer of claim 22. A molded article comprising the polymer according to claim 22.

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