JP2006045166A - Method for producing alicyclic polyvalent carboxylic acid and acid anhydride thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for industrially and advantageously producing the corresponding alicyclic polyvalent carboxylic acid and an acid anhydride thereof by hydrogenating aromatic polyvalent carboxylic acids (an aromatic polyvalent carboxylic acid or an acid anhydride thereof). <P>SOLUTION: The aromatic polyvalent carboxylic acid or the acid anhydride thereof is reacted with an aliphatic alcohol in the presence of a noble metal catalyst having a hydrogenating catalytic ability such as a ruthenium catalyst to afford an ester compound. The aromatic ring is subsequently hydrogenated in the presence of the catalyst. A solid acid catalyst such as an ion exchange resin catalyst is then made to exist to carry out hydrolysis. Thereby, the alicyclic polyvalent carboxylic acid is obtained. The resultant alicyclic polyvalent carboxylic acid is further cyclodehydrated to afford the alicyclic polyvalent carboxylic acid anhydride. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an alicyclic polycarboxylic acid from an aromatic polycarboxylic acid or an acid anhydride thereof (hereinafter referred to as aromatic polycarboxylic acid) and an acid anhydride thereof (hereinafter referred to as an alicyclic polycarboxylic acid). ) Manufacturing method. The alicyclic polycarboxylic acids are useful as raw materials for polyimides having properties such as transparency, heat discoloration, and solvent solubility.

Japanese Patent Publication No. 36-522 U.S. Pat. No. 3,520,921 US Pat. No. 5,412,108 JP 2002-020346 A JP 2002-193873 A JP 2003-286222 A JP-A-7-082221 U.S. Pat. No. 2,828,335 Japanese Patent Laid-Open No. 1-096147 JP 7-215912 A JP-A-8-325201 JP-A-8-325196 Japanese Patent Application Laid-Open No. 2004-026723 Journal of Organic Chemistry, 1966, 31, P. 3438

  As a manufacturing method of alicyclic polyhydric carboxylic acids, the method of hydrogenating the aromatic ring of aromatic polyhydric carboxylic acids (for example, patent documents 1-7, nonpatent literature 1), aromatic polyvalent carboxylate salt A method for hydrogenating an aromatic ring (for example, Patent Document 8) and a method for hydrogenating an aromatic ring of an aromatic polyvalent carboxylic acid ester (for example, Patent Documents 9 to 11) are known.

  In Patent Document 11, an aromatic polyvalent carboxylic acid ester having a different degree of esterification is produced by heating an aromatic polyvalent carboxylic acid and an aliphatic alcohol in the absence of a catalyst when producing an alicyclic polyvalent carboxylic acid ester. A method is disclosed in which a mixture is obtained (esterification step) and then heated in the presence of a noble metal hydrogenation catalyst and an aliphatic alcohol to perform nuclear hydrogenation (hydrogenation step). Although this method does not require the isolation of an aromatic ester and has the advantage that both esterification and hydrogenation steps can be carried out in the same reactor, the operation of adding a noble metal hydrogenation catalyst after the esterification step And industrially has some problems. For example, at temperatures recommended in the esterification step or hydrogenation step (180 to 230 ° C. in the former and 100 to 150 ° C. in the latter), all of methanol, ethanol, and 1-propanol that are particularly preferred as aliphatic alcohols As a method of adding a catalyst in a state where the vapor pressure exceeds atmospheric pressure, a method of pressurizing a catalyst suspended in a solvent can be mentioned. Equipment is required. On the other hand, a method is also conceivable in which a catalyst is introduced from a manhole after the temperature of the aliphatic alcohol has fallen below the allowable upper limit, but the time required for temperature reduction and reheating directly leads to a decrease in productivity and energy. There is also a problem with efficiency.

  Patent Documents 12 and 13 disclose hydrolysis and purification methods for alicyclic polycarboxylic esters, but improvements in esterification and nuclear hydrogenation processes and hydrolysis processes are desired. .

  An advantageous method for industrially producing an alicyclic polycarboxylic acid or an acid anhydride thereof is provided.

  In the present invention, an aromatic polycarboxylic acid or an acid anhydride thereof and an aliphatic alcohol are reacted in the presence of a noble metal catalyst having a hydrogenation catalytic ability to form an ester compound, and then an aromatic ring in the presence of the noble metal catalyst. Is a method for producing an alicyclic polyvalent carboxylic acid characterized by hydrogenating and then hydrolyzing.

  In the method for producing the alicyclic polycarboxylic acid, further satisfying any one or more of the following requirements provides a more preferred production method. 1) The reaction temperature when making an ester compound is 100 to 220 ° C., 2) the noble metal catalyst is a ruthenium catalyst, and 3) the step of making the ester compound and the step of hydrogenating the aromatic ring are the same. Performing in a reactor, 4) Hydrolysis is performed in the presence of a solid acid catalyst, or 5) The solid acid catalyst is an ion exchange resin. In addition, the present invention is a method for producing an alicyclic polycarboxylic acid anhydride, characterized by dehydrating and ring-closing the alicyclic polycarboxylic acid produced by any of the methods described above.

  The aromatic polyvalent carboxylic acid used as a raw material in the present invention is an aromatic polyvalent carboxylic acid or an acid anhydride thereof. Such aromatic polyvalent carboxylic acids include phthalic acid, 1,2,4-benzenetricarboxylic acid, 3-methylphthalic acid, 4-methylphthalic acid, 3,4,5,6-tetramethylphthalic acid, 5-methyl Examples include benzene-1,2,4-tricarboxylic acid, 6-methylbenzene-1,2,4-tricarboxylic acid, 3-methylbenzene-1,2,4-tricarboxylic acid, and anhydrides thereof. Biphenyl-3,3 ', 4,4'-tetracarboxylic acid, diphenyl ether-3,3', 4,4'-tetracarboxylic acid, benzophenone-3,3 ', 4,4'-tetracarboxylic acid, Diphenylmethane-3,3 ', 4,4'-tetracarboxylic acid, ethylidene-4,4'-bis (1,2-benzenedicarboxylic acid), propylidene-4,4'-bis (1,2-benzenedicarboxylic acid) ), 1,2,3,4-benzenetetracarboxylic acid, 1,2,4,5-benzenetetracarboxylic acid, 3-methylbenzene-1,2,4,5-tetracarboxylic acid, 3,6-dimethyl Examples thereof include benzene-1,2,4,5-tetracarboxylic acid and dianhydrides thereof. Further examples include benzenepentacarboxylic acid, benzenehexacarboxylic acid, and their dianhydrides or dianhydrides.

  The aliphatic alcohol used as another raw material includes a linear, branched or cyclic aliphatic alcohol having 1 to 6 carbon atoms. Specifically, methanol, ethanol, 1-propanol, 2 -Propanol, isobutanol, amyl alcohol, cyclohexanol and the like are exemplified, among which methanol and ethanol are preferable.

  The amount of the aliphatic alcohol used may be an amount equal to or higher than the stoichiometric amount required for esterifying the aromatic polyvalent carboxylic acids, but the aliphatic alcohol also acts as a solvent, so use it in excess. Is desirable. Preferably, it is 1 to 100 times the stoichiometry, more preferably 2 to 50 times.

  The catalyst used in the present invention is a noble metal catalyst having hydrogenation catalytic ability. This catalyst also acts as a catalyst for the esterification reaction. Examples of the noble metal catalyst include a catalyst in which a noble metal such as ruthenium or palladium is supported on a carrier that is usually used for preparing a hydrogenation catalyst. Particularly preferred are ruthenium-based catalysts. Examples of the carrier include activated carbon, alumina, silica, silica alumina, zirconium oxide, titanium oxide and the like. The supported amount of the noble metal is 0.1 to 10% by weight, preferably 1 to 5% in terms of noble metal. The form of the catalyst is appropriately selected from powder form, granular form and the like. The amount of the catalyst applied varies depending on the reaction conditions and the amount of noble metal supported, but is preferably 0.5 to 20% by weight, more preferably 1 to 5% by weight with respect to the aromatic polyvalent carboxylic acids.

  The reaction for synthesizing the ester compound is performed using an aromatic polyvalent carboxylic acid and an aliphatic alcohol in the presence of a noble metal catalyst. The esterification reaction temperature is in the range of 100 to 280 ° C, preferably 150 to 230 ° C. The reaction time is 0.1 to 10 hours, preferably 0.5 to 5 hours. Examples of the esterification reaction atmosphere gas include nitrogen, hydrogen, and the like, but hydrogen is preferable because it does not require a change in the atmosphere gas when the subsequent hydrogenation reaction is performed.

  When hydrogen is used as the esterification reaction atmosphere gas, a hydrogenation reaction occurs simultaneously with the esterification reaction, but the hydrogenation reaction does not sufficiently occur unless additional hydrogen consumed in the reaction is replenished. In the present invention, the hydrogenation reaction rate at the end of the esterification reaction is limited to 20% or less of the theoretical value.

  After completion of the esterification reaction, the aromatic ring is hydrogenated (nuclear hydrogenation) in the presence of the noble metal catalyst without removing the noble metal catalyst. Esterification in the presence of a noble metal catalyst having hydrogenation catalytic ability not only promotes esterification, but also requires removal of the catalyst and isolation of the ester to perform the next nuclear hydrogenation reaction. Therefore, there is an advantage that both steps can be performed in the same reactor.

  After completion of the esterification reaction, hydrogen is charged and a hydrogenation reaction is performed. In this case, a noble metal catalyst may be added if necessary, but the reaction operation becomes complicated. Therefore, the amount of the catalyst used in the hydrogenation reaction is preferably in the same range as the amount used in the esterification reaction. As the solvent for the hydrogenation reaction, it is advantageous to use the aliphatic alcohol used in the esterification reaction as it is.

  The hydrogen pressure is in the range of 0.1 to 20 MPa, preferably 0.5 to 10 MPa. When hydrogen is consumed during the reaction, the above pressure is additionally maintained, and when hydrogen consumption is not observed, the hydrogenation reaction is terminated. The hydrogenation reaction temperature is in the range of 60 to 170 ° C, preferably 100 to 150 ° C. The reaction time is usually about 0.5 to 20 hours.

  After completion of the reaction, the catalyst is recovered by filtration, and a hydrogenated ester (alicyclic polycarboxylic acid ester) is recovered from the filtrate containing the product. From the hydrogenated ester, the solvent and the ester are separated by distillation or the like, and the ester is hydrolyzed to obtain the desired alicyclic polycarboxylic acid. The recovered catalyst can be reused as it is or after being regenerated if necessary.

  As a method for hydrolyzing the alicyclic polyvalent carboxylic acid ester, a known method as described in Patent Document 12 can be adopted, but the alicyclic polyvalent carboxylic acid obtained by hydrolysis is highly soluble in water. For example, when a water-soluble acid is used as the catalyst, it is difficult to separate the catalyst from the catalyst. Therefore, a method in the presence of a solid acid catalyst is preferable. Examples of the solid acid catalyst include, but are not limited to, ion exchange resins, silica, alumina, silica-alumina, and zeolite. Hydrolysis is preferably carried out in the presence of an acid catalyst and excess water at a temperature not lower than the boiling point of the aliphatic alcohol produced by hydrolysis of the ester. In this case, the aliphatic alcohol produced by hydrolysis is not reacted during the reaction. It is preferable to take it out, and when the distillation of the aliphatic alcohol is no longer observed, the hydrolysis is terminated. In addition, when an aliphatic alcohol azeotropes with water, water is added if necessary.

  After completion of the hydrolysis reaction, a solid such as a catalyst is separated by filtration if necessary, and further separated from water by distillation or the like to obtain the desired alicyclic polycarboxylic acid. The alicyclic polyvalent carboxylic acid is purified by means such as recrystallization as necessary.

  When aiming at an alicyclic polycarboxylic acid anhydride, the alicyclic polycarboxylic acid obtained as described above is dehydrated to obtain an acid anhydride by a conventional method. As a method of dehydrating to acid anhydride, there is a method of reacting alicyclic polycarboxylic acid and acetic anhydride under reflux conditions.

According to the production method of the present invention, alicyclic polycarboxylic acids can be obtained with high productivity without requiring complicated operations.

An electromagnetic stirring autoclave with an internal volume of 200 ml was charged with 30.0 g of pyromellitic anhydride, 70.0 g of methanol, and 2.0 g of 5% Ru-carbon powder catalyst (manufactured by N.E. After replacing the system with hydrogen gas, esterification was carried out at 190 ° C. for 1 hour.
Next, the temperature was lowered to 130 ° C., and hydrogenation was performed while introducing hydrogen gas and maintaining the internal pressure at 4 MPa-G. The time required for the hydrogen absorption to stop was 5 hours, and the hydrogen absorption amount was 101.2% of the theoretical hydrogen absorption amount.

  The catalyst was filtered off, and then 40.0 g of cyclomethyl-1,2,4,5-tetracarboxylic acid tetramethyl ester obtained by distilling off methanol was added to a dropping funnel, a distillation tube, a thermometer and a stirrer. Place in a four-necked flask equipped with 25.0 g of ion exchange resin (Rohm and Haas, Amberlite 31), Nisseki Hysol SAS-296 (manufactured by Nippon Petrochemical Co., Ltd., high boiling aromatic hydrocarbon) 45.0 g and 45.0 g of distilled water were added and hydrolysis was performed at 100 ° C. Distilled water in an amount that compensates for the distilled water was added dropwise (about 10 ml / h), and the concentration of methanol in the distilled water was analyzed by gas chromatography to monitor the hydrolysis process. Methanol in the distilled water almost disappeared 24 hours after the start of hydrolysis. After adding 50 g of distilled water and cooling to 60 ° C., the ion exchange resin was filtered off, and water was distilled off from the filtrate to precipitate crystals. The crystals obtained by filtration were dried under reduced pressure at 80 ° C. and 5 mmHg to obtain 32.2 g of a white solid.

  10.0 g of white solid of cyclohexane-1,2,4,5-tetracarboxylic acid obtained above and 120 g of acetic anhydride were charged into a three-necked flask equipped with a condenser, a thermometer and a stirrer at 150 ° C. In an oil bath for 1 hour. Next, filtration was performed while hot, 175 g of toluene was added to the filtrate, and the mixture was cooled to room temperature to precipitate crystals. The crystals obtained by filtration were washed with toluene and dried under reduced pressure at 80 ° C. and 5 mmHg to obtain 6.0 g of white crystals. As a result of analysis by gas chromatography, the purity of cyclohexane-1,2,4,5-tetracarboxylic dianhydride was 99.2%. The yield of cyclohexane-1,2,4,5-tetracarboxylic dianhydride was 64.4% by weight (62.7 mol%) based on pyromellitic anhydride.

Comparative Example 1
An electromagnetic stirring autoclave with an internal volume of 200 ml was charged with 30 g of pyromellitic anhydride and 70 g of methanol, and the inside of the system was replaced with nitrogen gas, followed by esterification at 190 ° C. for 1 hour. Once cooled to room temperature, the autoclave was opened, 2.0 g of 5% Ru-carbon powder catalyst (manufactured by N.E. Chemcat Co., Ltd., 50 wt% water-containing product) was added, and the system was replaced with hydrogen gas. The hydrogenation was performed while introducing hydrogen gas and maintaining the internal pressure at 4 MPa-G. The time required for the hydrogen absorption to stop was 10 hours, and the hydrogen absorption amount was 95.0% of the theoretical hydrogen absorption amount.

Claims (7)

  An aromatic polycarboxylic acid or an acid anhydride thereof and an aliphatic alcohol are reacted in the presence of a noble metal catalyst having a hydrogenation catalytic ability to form an ester compound, and subsequently an aromatic ring is hydrogenated in the presence of the noble metal catalyst, Next, a method for producing an alicyclic polyvalent carboxylic acid, which is hydrolyzed.   The method for producing an alicyclic polyvalent carboxylic acid according to claim 1, wherein the reaction temperature when the ester compound is used is 100 to 220 ° C.   3. The method for producing an alicyclic polycarboxylic acid according to claim 1, wherein the noble metal catalyst is a ruthenium catalyst.   The method for producing an alicyclic polyvalent carboxylic acid according to any one of claims 1 to 3, wherein the step of forming an ester compound and the step of hydrogenating an aromatic ring are performed in the same reactor.   The method for producing an alicyclic polycarboxylic acid according to any one of claims 1 to 4, wherein the hydrolysis is performed in the presence of a solid acid catalyst.   The method for producing an alicyclic polycarboxylic acid according to claim 5, wherein the solid acid catalyst is an ion exchange resin.   A method for producing an alicyclic polycarboxylic acid anhydride, characterized in that the alicyclic polycarboxylic acid produced by the method according to claim 1 is dehydrated and closed.