JP2006083080A - Method for producing hydrogenated aromatic polycarboxylic acid - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a hydrogenated aromatic polycarboxylic acid, by which the highly pure hydrogenated aromatic polycarboxylic acid can profitably be produced in a high yield, and to provide the hydrogenated aromatic polycarboxylic acid substantially not containing an aromatic polycarboxylic acid of raw material. <P>SOLUTION: This method for producing the hydrogenated aromatic polycarboxylic acid, comprising subjecting the aromatic polycarboxylic acid to a nucleus hydrogenation reaction in the presence of a reaction solvent and a nucleus hydrogenation catalyst, is characterized in that the catalyst is a rhodium-γ-alumina-carrying catalyst obtained by carrying a rhodium metal on a γ-alumina carrier; the specific area of the carrier is 50 to 450 m<SP>2</SP>/g; and the amount of the rhodium metal in the catalyst is 0.25 to 0.5 pt. wt. per 100 pts. wt. of the aromatic polycarboxylic acid. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for producing a hydrogenated aromatic polycarboxylic acid by subjecting an aromatic ring of an aromatic polycarboxylic acid to a nuclear hydrogenation reaction, and a hydrogenated aromatic polycarboxylic acid obtained by the production method. More specifically, the present invention relates to a production method capable of industrially obtaining a high purity hydrogenated aromatic polycarboxylic acid with a high yield.

  Hydrogenated aromatic polycarboxylic acids are frequently used as raw materials for functional polyimides and functional epoxy resins. In recent years, as the functions of these resins have increased, high purity hydrogenated aromatic polycarboxylic acids have been demanded. In particular, for applications that require a high degree of transparency, there has been a strong demand for reducing the residual amount of aromatic rings in the hydrogenated aromatic polycarboxylic acid as much as possible.

  As a method for obtaining a high purity hydrogenated aromatic polycarboxylic acid, (i) a method of nuclear hydrogenating an aromatic polycarboxylic acid (see Non-Patent Document 1 and Patent Document 1), (ii) an aromatic polycarboxylic acid A method for nuclear hydrogenation of an aromatic ring via an ester derivative (see Patent Document 2 and Patent Document 3) has been proposed.

  Non-Patent Document 1 describes (i) pyromellitic acid at a hydrogen pressure of 2.7 atm and 60 ° C. in the presence of a catalyst (rhodium metal used amount: 2 wt% relative to raw material) with 5% rhodium metal supported on a carbon support. (Ii) 60-70 ° C. in the presence of a catalyst having 5% rhodium metal supported on an alumina support (amount of rhodium metal used; 2.4 wt% or 0.6 wt% relative to raw material) Describes a method for nuclear hydrogenation of phthalic acid, isophthalic acid or terephthalic acid.

  However, in any of the above methods, the amount of the catalyst used is large, and the conversion rate and selectivity of the aromatic polycarboxylic acid are not always sufficient, so that the raw material aromatic polycarboxylic acid tends to remain.

  Patent Document 1 discloses a method in which an aromatic carboxylic acid is subjected to a nuclear hydrogenation reaction in the presence of a catalyst containing a rhodium metal and / or a palladium metal. A method for producing a hydrogenated aromatic polycarboxylic acid of 10 to 10 parts by weight has been proposed. Specifically, a production method using a 5% by weight carbon-supported rhodium catalyst is described.

  However, this production method tends to increase the production cost, such as requiring a large amount of catalyst in the initial stage or reactivating the catalyst activity by activation treatment for each reaction. Moreover, since there was a tendency that a small amount of unreacted aromatic carboxylic acid remained, it could not be said that the quality was always satisfactory for applications requiring high transparency.

  Patent Document 2 and Patent Document 3 describe a method of nuclear hydrogenating an aromatic ring via an ester derivative of an aromatic polycarboxylic acid.

  However, since the production method is a method in which an aromatic polycarboxylic acid is once converted into an ester derivative and the aromatic ring is nuclear hydrogenated, the entire production process tends to be long and the reaction apparatus tends to be complicated. For this reason, manufacturing costs tend to increase.

“The Journal of Organic Chemistry”, 1966, Vol. 31, p. 3438-3439 JP 2003-286222 A JP-A-8-325196 JP-A-8-325201

  An object of the present invention is to provide a method for producing a high-purity hydrogenated aromatic polycarboxylic acid in an industrially advantageous manner in a high yield, and a hydrogenated aroma that is substantially free from the starting aromatic polycarboxylic acid. Is to provide a group polycarboxylic acid.

  As a result of intensive studies in order to solve the above-mentioned problems, the present inventors have obtained the following knowledge.

(1) The aromatic polycarboxylic acid as a raw material is substantially reduced by nuclear hydrogenation reaction of the aromatic polycarboxylic acid in the presence of a catalyst having rhodium metal supported on a specific support having a specific surface area in a specific range. Obtaining a high-purity hydrogenated aromatic polycarboxylic acid that does not contain,
(2) The desired effect can be obtained with a small amount of the catalyst,
(3) A high conversion rate and selectivity can be maintained even if the catalyst is repeatedly subjected to a nuclear hydrogenation reaction without activation.
The present invention has been completed based on such findings.

  That is, the present invention provides the following inventions.

(Item 1) In a method for producing a hydrogenated aromatic polycarboxylic acid by subjecting an aromatic polycarboxylic acid to a nuclear hydrogenation reaction in the presence of a catalyst and a reaction solvent, the catalyst carries a rhodium metal on a γ-alumina support. The rhodium-γ-alumina-supported catalyst obtained above has a specific surface area of 50 to 450 m ² / g, and the amount of rhodium metal in the catalyst is 100 parts by weight of aromatic polycarboxylic acid. A method for producing a hydrogenated aromatic polycarboxylic acid, wherein the proportion is 0.25 part by weight or more and less than 0.5 part by weight.

(Item 2) The method for producing a hydrogenated aromatic polycarboxylic acid according to Item 1, wherein the catalyst is a catalyst activated with hydrogen.

(Item 3) The method for producing a hydrogenated aromatic polycarboxylic acid according to Item 1 or 2, wherein the reaction solvent is water.

(Item 4) The method for producing a hydrogenated aromatic polycarboxylic acid according to any one of Items 1 to 3, wherein the reaction temperature of the nuclear hydrogenation reaction is 40 to 90 ° C.

(Item 5) The method for producing a hydrogenated aromatic polycarboxylic acid according to any one of Items 1 to 4, wherein the hydrogen partial pressure of the nuclear hydrogenation reaction is 2 to 20 MPa.

(Item 6) The hydrogenation according to any one of Items 1 to 5, wherein the substrate concentration of the aromatic polycarboxylic acid is 5 to 40% by weight based on the total weight of the aromatic polycarboxylic acid and the reaction solvent. A method for producing an aromatic polycarboxylic acid.

(Item 7) The method for producing a hydrogenated aromatic polycarboxylic acid according to any one of Items 1 to 6, wherein the aromatic polycarboxylic acid is pyromellitic acid, trimellitic acid or trimesic acid.

(Item 8) A hydrogenated aromatic polycarboxylic acid obtained by the production method according to any one of Items 1 to 7, wherein the content of the raw material aromatic polycarboxylic acid is 0.05% by weight or less.

According to the present invention, high-purity hydrogenated aromatic polycarboxylic acid can be industrially advantageously produced in high yield.
In addition, the hydrogenated aromatic polycarboxylic acid obtained by the production method of the present invention has a very small amount of aromatic polycarboxylic acid as a raw material or substantially does not contain it, so that it has transparency and solvent solubility. It is useful as a monomer raw material for functional polyimide and polyester, and as a raw material for a curing agent for functional epoxy resin having transparency.

  The aromatic polycarboxylic acid according to the present invention is not particularly limited as long as it is a compound having two or more, preferably three or more carboxyl groups on the aromatic ring, and known aromatic polycarboxylic acids can be used.

  Specifically, phthalic acid, isophthalic acid, terephthalic acid, 1,2-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid, 2,6- Naphthalenedicarboxylic acid, 9,10-anthracene dicarboxylic acid, 4,4′-benzophenone dicarboxylic acid, 2,2′-biphenyl dicarboxylic acid, 3,3′-biphenyl dicarboxylic acid, 4,4′-biphenyl dicarboxylic acid, 3, Aromatic dicarboxylic acids such as 3′-biphenyl ether dicarboxylic acid, 4,4′-biphenyl ether dicarboxylic acid, 4,4′-binaphthyl dicarboxylic acid,

Aromatic tricarboxylic acids such as hemimellitic acid, trimellitic acid, trimesic acid, 1,2,4-naphthalenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid,

Merophanic acid, planitic acid, pyromellitic acid, 3,3 ′, 4,4′-benzophenone tetracarboxylic acid, 2,2 ′, 3,3′-benzophenone tetracarboxylic acid, 2,3,3 ′, 4′- Benzophenone tetracarboxylic acid, 3,3 ′, 4,4′-biphenyltetracarboxylic acid, 2,2 ′, 3,3′-biphenyltetracarboxylic acid, 2,3,3 ′, 4′-biphenyltetracarboxylic acid, 4,4′-oxydiphthalic acid, 3,3 ′, 4,4′-diphenylmethanetetracarboxylic acid, 1,4,5,8-naphthalenetetracarboxylic acid, 1,2,5,6-naphthalenetetracarboxylic acid, 2 , 3,6,7-naphthalenetetracarboxylic acid, aromatic tetracarboxylic acid such as anthracenetetracarboxylic acid,

Examples include aromatic pentacarboxylic acids such as benzenepentacarboxylic acid and aromatic hexacarboxylic acids such as benzenehexacarboxylic acid. These can be used alone or in appropriate combination of two or more.

  Of these, aromatic polycarboxylic acids having 3 or more carboxyl groups are preferred.

  Specifically, pyromellitic acid, trimellitic acid, trimesic acid, 2,3,6,7-naphthalenetetracarboxylic acid, 3,3 ′, 4,4′-biphenyltetracarboxylic acid are preferable, pyromellitic acid, Trimellitic acid and trimesic acid are more preferable. These can be used alone or in appropriate combination of two or more.

The catalyst according to the present invention is a catalyst in which a rhodium metal is supported on a γ-alumina carrier having a specific surface area of 50 to 450 m ² / g, preferably 80 to 350 m ² / g, more preferably 80 to 250 m ² / g ( Hereinafter, it is referred to as a rhodium-γ-alumina supported catalyst.
By selecting γ crystal form alumina as the support and setting the specific surface area within the above range, it is not necessary to carry out the activation treatment of the catalyst for each reaction, and a significant improvement in the catalyst activity is recognized.

  The amount of rhodium metal supported on the γ-alumina carrier is preferably 1 to 10% by weight, more preferably 2 to 5% by weight, based on the total weight of the γ-alumina carrier and rhodium metal.

  The amount of the rhodium metal used in the nuclear hydrogenation reaction according to the present invention is 0.25 parts by weight with respect to 100 parts by weight of the aromatic polycarboxylic acid based on the rhodium metal content in the rhodium-γ-alumina supported catalyst. The ratio is less than 0.5 parts by weight, preferably 0.25 to 0.4 parts by weight. If the amount is less than 0.25 parts by weight, the nuclear hydrogenation reaction may not proceed sufficiently, and if the amount is 0.5 parts by weight or more, it is difficult to obtain an effect commensurate with the amount, resulting in an increase in production cost. .

  The method for preparing the catalyst is not particularly limited as long as the effects of the present invention are not impaired, and examples thereof include an impregnation method, a precipitation method, and an ion exchange method (for example, “Catalyst Society”, “Catalyst Design”, Catalyst Lecture 5, p39-P45, Kodansha Scientific (1985)).

The rhodium-γ-alumina supported catalyst according to the present invention has an advantage that even if it is repeatedly used for the nuclear hydrogenation reaction of an aromatic polycarboxylic acid, the decrease in the catalytic activity is small.
For example, when a nuclear hydrogenation reaction is performed in batch mode, depending on the reaction conditions, it is not necessary to perform activation treatment for each reaction, and even if the nuclear hydrogenation reaction is continuously performed, The decrease is very small or no substantial decrease is observed. Such advantages greatly contribute to the reduction of production costs.

  The rhodium-γ-alumina-supported catalyst according to the present invention can be used for the nuclear hydrogenation reaction as it is, but by reducing and activating in advance with hydrogen, the catalytic activity can be effectively expressed, This is effective in reducing the reaction time of the nuclear hydrogenation reaction.

  As the catalyst activation treatment conditions, the following treatment conditions are recommended.

  Usually, the activation treatment is performed in the presence of hydrogen and a treatment solvent. The treatment solvent is preferably the same type as the reaction solvent used in the nuclear hydrogenation reaction according to the present invention described later, and water is particularly preferred. The hydrogen partial pressure is preferably 0.5 to 5 MPa, and particularly preferably 0.5 to 2 MPa. The treatment temperature is preferably 40 to 90 ° C, particularly preferably 50 to 70 ° C. The treatment time is usually 0.5 to 2 hours depending on the treatment conditions.

The nuclear hydrogenation reaction according to the present invention is performed in the presence of a reaction solvent. The reaction solvent may be any solvent that can dissolve or uniformly disperse or suspend the aromatic polycarboxylic acid.
Moreover, this reaction solvent needs to have appropriate solubility with respect to the said hydrogenated aromatic polycarboxylic acid.

  Examples of the reaction solvent include ether compounds such as ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, and triethylene glycol dimethyl ether, and water. These can be used alone or in appropriate combination of two or more.

Among the reaction solvents, water is particularly preferable. The water is preferably ion exchange water or distilled water.
In addition, when the hydrogenated aromatic polycarboxylic acid according to the present invention is used in the electric / electronic field, it is preferable to use water having as little content as possible of metal components such as sodium, potassium, calcium, magnesium, and iron. .

By selecting water as the reaction solvent
(I) Since the aromatic polycarboxylic acid is easily dissolved in water, the nuclear hydrogenation reaction is likely to proceed.
(Ii) Since the obtained hydrogenated aromatic polycarboxylic acid is easily dissolved in water, separation from the catalyst is easy.
(Iii) After separating the catalyst, the filtrate is concentrated or cooled to crystallize the hydrogenated aromatic polycarboxylic acid, and the liquid is separated into solid and liquid by filtration, centrifugation, etc. It is easy to obtain a hydrogenated aromatic polycarboxylic acid of
Advantages such as are obtained.

The substrate concentration of the aromatic polycarboxylic acid in the nuclear hydrogenation reaction according to the present invention is preferably 5 to 40% by weight with respect to the total weight of the aromatic polycarboxylic acid and the reaction solvent.
The substrate concentration is preferably such that most of the target hydrogenated aromatic polycarboxylic acid dissolves at the reaction temperature of the nuclear hydrogenation reaction.

  The reaction temperature of the nuclear hydrogenation reaction according to the present invention is preferably 40 to 90 ° C, particularly preferably 50 to 70 ° C. A significant improvement in reaction activity is observed within this reaction temperature range.

  The hydrogen partial pressure of the nuclear hydrogenation reaction according to the present invention is preferably 2 to 20 MPa, and particularly preferably 3 to 10 MPa. When the hydrogen partial pressure is less than 2 MPa, it is difficult to obtain a desired conversion rate, and the object of the present invention may not be achieved. When the hydrogen partial pressure exceeds 20 MPa, it is difficult to obtain an effect commensurate with it.

  The reaction time of the nuclear hydrogenation reaction according to the present invention depends on the reaction conditions such as substrate concentration, catalyst amount, hydrogen partial pressure, reaction temperature, reactor shape, stirrer shape, stirring speed, etc. It is about time.

  The reactor used for the nuclear hydrogenation reaction according to the present invention is as follows: (i) the reactor is an acid-resistant material, (ii) a pressure-resistant structure, and (iii) a catalyst and an aromatic polycarboxylic acid are sufficiently mixed The reaction apparatus is not particularly limited as long as it is equipped with a stirrer that can be used, and a known reaction apparatus can also be used. For example, a vertical or horizontal autoclave made of SUS316L can be used.

  The procedure for the nuclear hydrogenation reaction according to the present invention is not particularly limited as long as the effects of the present invention are not impaired.

  For example, a predetermined amount of a predetermined raw material, reaction solvent, and catalyst are charged into a reaction apparatus, and the inside of the system is replaced with an inert gas. Next, a procedure for substituting with hydrogen and performing a nuclear hydrogenation reaction under predetermined reaction conditions (hydrogen partial pressure, reaction temperature, reaction time, stirring speed, etc.) is exemplified.

  Alternatively, a procedure may be used in which a catalyst and a reaction solvent are charged into a reactor, the catalyst is activated according to the above-described processing conditions, and then a raw material is charged.

  As a post-treatment method after completion of the reaction, for example, (1) after completion of the reaction, the catalyst is filtered off at a temperature comparable to the reaction temperature. The filtrate is cooled to room temperature and crystallized. After crystallization, filtration, and the filtrate is dried under reduced pressure (for example, 10 KPa or less, 60 to 110 ° C., 3 to 20 hours) to obtain the target hydrogenated aromatic polycarboxylic acid,

(2) The reaction solvent is distilled off from the filtrate under reduced pressure and concentrated. After concentration, the precipitated solid is filtered off. Next, a method of obtaining the target hydrogenated aromatic polycarboxylic acid by drying the filtrate under reduced pressure is exemplified.

  In addition, when a relatively large amount of hydrogenated aromatic polycarboxylic acid is precipitated after the completion of the nuclear hydrogenation reaction, a procedure such as increasing the filtration temperature or adding a reaction solvent may be added, and the system thickens during crystallization. In this case, a procedure such as adding a reaction solvent in advance after completion of the reaction may be added.

  The catalyst separated by filtration can be repeatedly used for the nuclear hydrogenation reaction.

Thus, according to the method for producing a hydrogenated aromatic polycarboxylic acid of the present invention, a high-purity hydrogenated aromatic polycarboxylic acid can be produced by a simple process and an industrially advantageous method.
Note that the content of the aromatic polycarboxylic acid of the raw material described above is extremely small or substantially not contained is below the lower limit of detection of the aromatic polycarboxylic acid of the raw material in the gas chromatography method. Means.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated in detail, this invention is not limited to these Examples.

[Composition analysis by gas chromatography]
Composition analysis was performed by gas chromatography (hereinafter referred to as GLC method).
<Pretreatment>
The sample was dissolved in diethylene glycol dimethyl ether to a solid concentration of 6% by weight. Next, the solution was methyl esterified with diazomethane to prepare a sample for GLC. The injection volume is 0.8 μL.
<GLC analysis conditions>
GLC analyzer; GC-17A (manufactured by Shimadzu Corporation)
Capillary column; CBP-10-25M-0.25 (manufactured by Shimadzu Corporation)
Injection temperature: 250 ° C
Detector temperature: 250 ° C
Column temperature: 140 to 240 ° C., temperature rising rate: 4 ° C./min carrier gas; helium carrier gas pressure; 130 KPa
Detector; FID

[Conversion rate calculation method]
From the peak area ratio A (%) corresponding to the starting aromatic polycarboxylic acid obtained from the GLC composition analysis, the conversion rate was calculated using the formula (1).
Conversion rate (%) = (100−A) (1)

[Selection rate calculation method]
From the conversion C (%) and the peak area ratio B (%) corresponding to the target hydrogenated aromatic polycarboxylic acid, the selectivity was calculated using the formula (2).
Selectivity (%) = (B / C) × 100 (2)

[Reaction yield and purity]
The peak area ratio B (%) corresponding to the target hydrogenated aromatic polycarboxylic acid was defined as the reaction yield (%) in the case of the reaction intermediate, and the purity (area%) in the case of the dried product.

[yield]
From the weight E (g) of the dried product obtained by hydrogenation, crystallization, and drying, based on the charged weight D (g) of the aromatic polycarboxylic acid of the raw material, the yield is calculated using the formula (3). Calculated.
Yield (% by weight) = (E / D) × 100 (3)

[Example 1]
A 500 mL autoclave made of SUS316-L equipped with a stirrer, a thermometer, a pressure gauge, and an introduction tube was mixed with 20 g of pyromellitic acid, 80 g of ion-exchanged water, and 5 wt% rhodium having a specific surface area of 150 m ² / g of the carrier. 1.6 g of γ-alumina-supported catalyst (manufactured by N-Chemcat) (0.4 parts by weight as rhodium metal) was charged, and the system was replaced twice with nitrogen gas and then five times with hydrogen gas while stirring. . After the replacement, the temperature was raised while maintaining a hydrogen partial pressure of 5 MPa, and a nuclear hydrogenation reaction was carried out at a reaction temperature of 60 ° C. for 1.5 hours.
The reaction solution was extracted from the autoclave, and the catalyst was suction filtered (filter paper; No. 5C) to obtain a colorless and transparent filtrate. The filtrate (reaction crude) was analyzed by GLC method. The analysis results (pyromellitic acid conversion, selectivity of 1,2,4,5-cyclohexanetetracarboxylic acid and reaction yield) are shown in Table 2.
Next, the reaction solvent was distilled off from the above filtrate under reduced pressure (oil bath temperature; 105 ° C.) and concentrated to 50% by weight. Next, after cooling to room temperature, the precipitated solid was subjected to suction filtration, and the filtrate was washed with a small amount of cold water. The obtained solid was dried under reduced pressure at 90 ° C. and 0.7 KPa for 10 hours to obtain 14.3 g (yield 71.5 wt%) of 1,2,4,5-cyclohexanetetracarboxylic acid. The results of GLC analysis of the dried product are shown in Table 2.
Table 1 shows the reaction conditions for the nuclear hydrogenation reaction of Example 1 and Examples 2 to 17 and Comparative Examples 1 to 4 described later.

[Example 2]
The same procedure as in Example 1 was conducted, except that 1.6 g of the rhodium-γ-alumina supported catalyst was changed to 1.2 g and the reaction time was changed to 1.5 hours.
The reaction crude was analyzed by the GLC method in the same manner as in Example 1, and the results are shown in Table 2.
Further, post-treatment was performed in the same manner as in Example 1 to obtain 14.2 g (yield 71 wt%) of 1,2,4,5-cyclohexanetetracarboxylic acid. The results of GLC analysis of the dried product are shown in Table 2.

[Example 3]
The rhodium-γ-alumina-supported catalyst separated by filtration in Example 2 was immediately charged into the autoclave together with 20 g of pyromellitic acid and 80 g of ion-exchanged water, and a nuclear hydrogenation reaction was carried out in the same manner as in Example 2. Thereafter, the same operation was repeated four times to conduct a catalyst recycling experiment.
The reaction crude obtained by the fifth catalyst recycling was analyzed by the GLC method in the same manner as in Example 1, and the results are shown in Table 2. From the analysis results, almost no decrease in the activity of the catalyst was observed.
The reaction crude was post-treated in the same manner as in Example 1 to obtain 14.1 g (yield 70.5% by weight) of 1,2,4,5-cyclohexanetetracarboxylic acid. The results of GLC analysis of the dried product are shown in Table 2.

[Example 4]
Other than changing 20 g of pyromellitic acid to 30 g, 80 g of ion-exchanged water, 90 g of 5 wt% rhodium-γ-alumina supported catalyst to 1.8 g, and changing the reaction time from 2 hours to 2.5 hours, The same operation as in Example 2 was performed.
The reaction crude was analyzed by the GLC method in the same manner as in Example 1, and the results are shown in Table 2.
Further, post-treatment was performed in the same manner as in Example 1 to obtain 21.3 g of 1,2,4,5-cyclohexanetetracarboxylic acid (yield 71 wt%). The results of GLC analysis of the dried product are shown in Table 2.

[Example 5]
The rhodium-γ-alumina supported catalyst separated by filtration in Example 4 was immediately charged into the autoclave together with 30 g of pyromellitic acid and 90 g of ion-exchanged water, and a nuclear hydrogenation reaction was carried out in the same manner as in Example 4. Thereafter, the same operation was repeated four times to conduct a catalyst recycling experiment.
The reaction crude obtained by the fifth catalyst recycling was analyzed by the GLC method in the same manner as in Example 1, and the results are shown in Table 2. From the analysis results, almost no decrease in the activity of the catalyst was observed.
Further, the reaction crude was subjected to post-treatment in the same manner as in Example 1 to obtain 21.3 g of 1,2,4,5-cyclohexanetetracarboxylic acid (yield 71 wt%). The results of GLC analysis of the dried product are shown in Table 2.

[Example 6]
The reaction was carried out in the same manner as in Example 2 except that ion-exchanged water was replaced with distilled water, the reaction temperature was changed from 60 ° C. to 50 ° C., and the reaction time was changed from 2 hours to 2.5 hours.
The reaction crude was analyzed by the GLC method in the same manner as in Example 1, and the results are shown in Table 2. Further, post-treatment was performed in the same manner as in Example 1 to obtain 14.2 g (yield 71 wt%) of 1,2,4,5-cyclohexanetetracarboxylic acid. The results of GLC analysis of the dried product are shown in Table 2.

[Example 7]
The same procedure as in Example 2 was performed, except that the specific surface area 150 m ² / g of the carrier of the rhodium-γ-alumina supported catalyst was changed to 100 m ² / g.
The reaction crude was analyzed by the GLC method in the same manner as in Example 1, and the results are shown in Table 2. Further, post-treatment was carried out in the same manner as in Example 1 to obtain 14.0 g (yield 70% by weight) of 1,2,4,5-cyclohexanetetracarboxylic acid. The results of GLC analysis of the dried product are shown in Table 2.

[Example 8]
The same procedure as in Example 2 was conducted, except that the specific surface area 150 m ² / g of the carrier of the rhodium-γ-alumina supported catalyst was changed to 300 m ² / g.
The reaction crude was analyzed by the GLC method in the same manner as in Example 1, and the results are shown in Table 2. Further, post-treatment was performed in the same manner as in Example 1 to obtain 13.9 g (yield 69.5% by weight) of 1,2,4,5-cyclohexanetetracarboxylic acid. The results of GLC analysis of the dried product are shown in Table 2.

[Example 9]
First, 1.2 g of a rhodium-γ-alumina supported catalyst and 80 g of water were put into the autoclave, and the system was replaced twice with nitrogen gas and then five times with hydrogen gas. After the replacement, the catalyst was activated by reduction with a hydrogen partial pressure of 5 MPa, a treatment temperature of 60 ° C., and a treatment time of 1 hour. Next, 20 g of pyromellitic acid was added, and a nuclear hydrogenation reaction was performed at a hydrogen partial pressure of 5 MPa and a reaction temperature of 60 ° C. for 1.5 hours.
The reaction crude was analyzed by the GLC method in the same manner as in Example 1, and the results are shown in Table 2. As a result, the reaction time was shortened.
Further, post-treatment was performed in the same manner as in Example 1 to obtain 14.1 g (yield: 70.5% by weight) of 1,2,4,5-cyclohexanetetracarboxylic acid. The results of GLC analysis of the dried product are shown in Table 2.

[Example 10]
The same procedure as in Example 2 was performed except that 20 g of pyromellitic acid was replaced with 20 g of trimellitic acid and the reaction time was changed from 2 hours to 2.5 hours.
The reaction crude was analyzed by the GLC method in the same manner as in Example 1, and the analysis results (conversion rate of trimellitic acid, selectivity of 1,2,4-cyclohexanetricarboxylic acid and reaction yield) are shown in Table 2. .
Further, post-treatment was performed in the same manner as in Example 1 to obtain 14.0 g of 1,2,4-cyclohexanetricarboxylic acid (yield 70% by weight). The results of GLC analysis of the dried product are shown in Table 2.

[Example 11]
The rhodium-γ-alumina supported catalyst separated by filtration in Example 10 was immediately charged into the autoclave together with 20 g of pyromellitic acid and 80 g of ion-exchanged water, and a nuclear hydrogenation reaction was carried out in the same manner as in Example 10. Thereafter, the same operation was repeated four times to conduct a catalyst recycling experiment.
The reaction crude obtained by the fifth catalyst recycling was analyzed by the GLC method in the same manner as in Example 1, and the results are shown in Table 2. From the analysis results, almost no decrease in the activity of the catalyst was observed.
Further, the reaction crude was subjected to post-treatment in the same manner as in Example 1 to obtain 14.1 g (yield 70.5% by weight) of 1,2,4-cyclohexanetricarboxylic acid. The results of GLC analysis of the dried product are shown in Table 2.

[Example 12]
The same procedure as in Example 10 was performed except that the specific surface area 150 m ² / g of the carrier of the rhodium-γ-alumina supported catalyst was changed to 100 m ² / g.
The reaction crude was analyzed by the GLC method in the same manner as in Example 1, and the results are shown in Table 2.
Further, post-treatment was performed in the same manner as in Example 1 to obtain 13.9 g (yield: 69.5% by weight) of 1,2,4-cyclohexanetricarboxylic acid. The results of GLC analysis of the dried product are shown in Table 2.

[Example 13]
The same procedure as in Example 10 was performed, except that the specific surface area of 150 m ² / g of the rhodium-γ-alumina supported catalyst support was changed to 300 m ² / g.
The reaction crude was analyzed by the GLC method in the same manner as in Example 1, and the results are shown in Table 2.
Further, post-treatment was performed in the same manner as in Example 1 to obtain 13.8 g of 1,2,4-cyclohexanetricarboxylic acid (yield 69 wt%). The results of GLC analysis of the dried product are shown in Table 2.
[Example 14]
The same procedure as in Example 2 was performed except that 20 g of pyromellitic acid was replaced with 20 g of trimesic acid and the reaction time was changed from 2 hours to 1 hour.
The reaction crude was analyzed by the GLC method in the same manner as in Example 1. The analysis results (conversion rate of trimesic acid, selectivity of 1,3,5-cyclohexanetricarboxylic acid and reaction yield) are shown in Table 2.
Further, post-treatment was performed in the same manner as in Example 1 to obtain 14.3 g (yield 71 wt%) of 1,3,5-cyclohexanetricarboxylic acid. The results of GLC analysis of the dried product are shown in Table 2.

[Example 15]
The rhodium-γ-alumina supported catalyst separated by filtration in Example 14 was immediately charged into the autoclave together with 20 g of pyromellitic acid and 80 g of ion-exchanged water, and a nuclear hydrogenation reaction was carried out in the same manner as in Example 14. Thereafter, the same operation was repeated four times to conduct a catalyst recycling experiment.
The reaction crude obtained by the fifth catalyst recycling was analyzed by the GLC method in the same manner as in Example 1, and the results are shown in Table 2. From the analysis results, almost no decrease in the activity of the catalyst was observed.
Further, the reaction crude was subjected to post-treatment in the same manner as in Example 1 to obtain 14.1 g (yield 70.5% by weight) of 1,3,5-cyclohexanetricarboxylic acid. The results of GLC analysis of the dried product are shown in Table 2.

[Example 16]
The same procedure as in Example 14 was performed, except that the specific surface area of 150 m ² / g of the carrier of the rhodium-γ-alumina supported catalyst was changed to 100 m ² / g.
The reaction crude was analyzed by the GLC method in the same manner as in Example 1, and the results are shown in Table 2.
Further, post-treatment was performed in the same manner as in Example 1 to obtain 14.0 g of 1,3,5-cyclohexanetricarboxylic acid (yield 70 wt%). The results of GLC analysis of the dried product are shown in Table 2.

[Example 17]
The same procedure as in Example 14 was performed, except that the specific surface area of 150 m ² / g of the carrier of the rhodium-γ-alumina supported catalyst was changed to 300 m ² / g.
The reaction crude was analyzed by the GLC method in the same manner as in Example 1, and the results are shown in Table 2.
Further, post-treatment was performed in the same manner as in Example 1 to obtain 14.0 g of 1,3,5-cyclohexanetricarboxylic acid (yield 70 wt%). The results of GLC analysis of the dried product are shown in Table 2.

[Comparative Example 1]
A rhodium-γ-alumina supported catalyst having a specific surface area of 150 m ² / g is a catalyst in which a rhodium metal is supported on a carbon support having a specific surface area of 794 m ² / g (hereinafter referred to as a rhodium-carbon supported catalyst; manufactured by N.I. Catcat). The procedure was the same as in Example 1 except that was replaced.
The reaction crude was analyzed by the GLC method in the same manner as in Example 1, and the results are shown in Table 2.
Further, post-treatment was performed in the same manner as in Example 1 to obtain 13.4 g of 1,2,4,5-cyclohexanetetracarboxylic acid (yield: 67% by weight). The results of GLC analysis of the dried product are shown in Table 2.

[Comparative Example 2]
The same procedure as in Comparative Example 1 was conducted except that 1.6 g of the rhodium-carbon supported catalyst was changed to 2.0 g and the reaction time was changed from 1.5 hours to 2 hours.
The reaction crude was analyzed by the GLC method in the same manner as in Example 1, and the results are shown in Table 2.
Further, post-treatment was performed in the same manner as in Example 1 to obtain 13.6 g of 1,2,4,5-cyclohexanetetracarboxylic acid (yield: 68% by weight). The results of GLC analysis of the dried product are shown in Table 2.

[Comparative Example 3]
The rhodium-carbon supported catalyst separated by filtration in Comparative Example 2 was immediately charged into the autoclave together with 20 g of pyromellitic acid and 80 g of ion-exchanged water, and a nuclear hydrogenation reaction was carried out in the same manner as in Comparative Example 2.
The reaction crude was analyzed by the GLC method in the same manner as in Example 1, and the results are shown in Table 2. From the analysis results, a decrease in the activity of the catalyst was observed despite one reuse.
Further, post-treatment was performed in the same manner as in Example 1 to obtain 13.5 g of 1,2,4,5-cyclohexanetetracarboxylic acid (yield 67.5 wt%). The results of GLC analysis of the dried product are shown in Table 2.

[Comparative Example 4]
Example 2 except that the rhodium-γ-alumina supported catalyst having a specific surface area of 150 m ² / g was replaced with a catalyst (manufactured by N.I. Chemcat) having a rhodium metal supported on a titania support having a specific surface area of 101 m ² / g. As well as.
The reaction crude was analyzed by the GLC method in the same manner as in Example 1, and the results are shown in Table 2.
Further, post-treatment was performed in the same manner as in Example 1 to obtain 12.9 g (yield 64.5% by weight) of 1,2,4,5-cyclohexanetetracarboxylic acid. The results of GLC analysis of the dried product are shown in Table 2.

By the production method of the present invention, a hydrogenated aromatic polycarboxylic acid having a high yield and high purity can be industrially obtained.
In addition, the hydrogenated aromatic polycarboxylic acid obtained by the production method of the present invention requires very high transparency because the raw material aromatic polycarboxylic acid is a trace amount or does not substantially contain. It is useful as a raw material for high-functional polyimide and high-functional epoxy resin.

Claims (8)

Rhodium obtained by supporting a rhodium metal on a γ-alumina support in a process for producing a hydrogenated aromatic polycarboxylic acid by nuclear hydrogenation reaction of an aromatic polycarboxylic acid in the presence of a catalyst and a reaction solvent -Γ-alumina supported catalyst, wherein the support has a specific surface area of 50 to 450 m ² / g, and the amount of rhodium metal in the catalyst is 0.25 weight with respect to 100 parts by weight of the aromatic polycarboxylic acid. A method for producing a hydrogenated aromatic polycarboxylic acid, characterized in that the proportion is at least 0.5 parts by weight.   The method for producing a hydrogenated aromatic polycarboxylic acid according to claim 1, wherein the catalyst is a catalyst activated with hydrogen.   The method for producing a hydrogenated aromatic polycarboxylic acid according to claim 1 or 2, wherein the reaction solvent is water.   The method for producing a hydrogenated aromatic polycarboxylic acid according to any one of claims 1 to 3, wherein the reaction temperature of the nuclear hydrogenation reaction is 40 to 90 ° C.   The method for producing a hydrogenated aromatic polycarboxylic acid according to any one of claims 1 to 4, wherein the hydrogen partial pressure of the nuclear hydrogenation reaction is 2 to 20 MPa.   The hydrogenated aromatic polycarboxylic acid according to any one of claims 1 to 5, wherein the substrate concentration of the aromatic polycarboxylic acid is 5 to 40% by weight based on the total weight of the aromatic polycarboxylic acid and the reaction solvent. Acid production method.   The method for producing a hydrogenated aromatic polycarboxylic acid according to any one of claims 1 to 6, wherein the aromatic polycarboxylic acid is pyromellitic acid, trimellitic acid or trimesic acid. A hydrogenated aromatic polycarboxylic acid obtained by the production method according to claim 1, wherein the content of the raw material aromatic polycarboxylic acid is 0.05% by weight or less.