JPH03223233A - Production of naphthalene carboxylic acid ester - Google Patents

Abstract

PURPOSE:To obtain the subject ester compound in high purity from a substituted naphthalene through naphthalene carboxylic acid thereof by recovering a heavy metal catalyst used in the production of subject ester compound with high yield after the esterification from the filtered solution and/or the washed solution as a carbonate. CONSTITUTION:Substituted naphthalene is oxidized by molecular oxygen in a solvent containing a lower aliphatic monocarboxylic acid and in the presence of a noble metal catalyst to obtain a crude naphthalene carboxylic acid containing the noble metal catalyst. Next, a resultant crude naphthalene carboxylic acid is esterified in an alkylalcohol and in the presence of an esterification catalyst and a resultant reaction product is filtered, a resultant filtered solution and/or resultant esterified substance is washed at least with >=1 kinds among water, an aqueous solution of acid or alkylalcohol, then a compound generating carbonate ion is added to the resultant washed solution or the concentrated solution thereof to convert dissolved heavy metal catalyst to an insoluble carbonate and is recovered in a high yield to make possible to use circularly for industrially advantageous production of the subject compound useful as a raw material for photographic agent or dye, etc., in high purity.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention is directed to producing naphthalene carboxylic acid by oxidizing substituted naphthalene with molecular oxygen in a solvent containing a lower aliphatic monocarboxylic acid in the presence of a heavy metal catalyst. rNCA below
,) is subjected to an esterification reaction, and the heavy metal catalyst is recovered as a carbonate from the filtrate obtained by filtering the esterification reaction product and/or the washing solution of the esterified product.Production of naphthalene carboxylic acid ester Regarding the method.

[Prior Art] NCA, such as naphthoic acid, is used as a raw material for photographic drugs and dyes, and naphthalene dicarboxylic acids, especially 2.6 monomer, are used for films and textile products with excellent heat resistance, mechanical strength, and dimensional stability. It is used as a raw material for polyethylene naphthalate, polyester, polyamide, etc. used in the production of

Furthermore, naphthalenetricarboxylic acid and naphthalenetetracarboxylic acid are seen as promising raw materials for highly functional resins and the like.

Conventionally, many proposals have been made as methods for manufacturing NCA. For example, a method of oxidizing alkylnaphthalenes and acylnaphthalenes with a molecular oxygen-containing gas in a solvent containing a lower aliphatic monocarboxylic acid such as acetic acid in the presence of a catalyst consisting of heavy metals consisting of cobalt and manganese and bromine (Tokuko Showa) 48-43893, JP 56-21017, JP 59-13495, JP 49-4
2654, JP-A-60-89445, JP-A-60-89446), or a method in which the oxidation reaction is carried out using a heavy metal consisting of cobalt and cerium and bromine as a catalyst (JP-A-62212344). etc. are known.

NCA obtained by the above method is sometimes used as it is for various purposes, but in many cases NCA is subjected to an esterification reaction and the obtained NCA ester is used.

As a method for esterifying NCA, NCA is subjected to a predetermined reaction using a predetermined amount of methyl alcohol in the presence of one or more catalysts selected from the group consisting of sulfuric acid, hydrochloric acid, and sulfonic acid. A method of carrying out an esterification reaction at temperature and under pressure (Japanese Patent Publication No. 174-1983),
Many proposals have been made, including a method in which NCA is brought into contact with an NCA ester or an NCA esterification intermediate at a predetermined temperature and then supplied to an esterification reaction vessel (Japanese Unexamined Patent Publication No. 76056/1983).

However, in order to produce the NCA ester on an industrial scale at low cost and in high yield, it is very important to recover and recycle the heavy metal catalyst during NCA production.

Furthermore, if the heavy metal catalyst from NCA production remains in the NCA ester, it will have a negative effect on the final product, such as a film or fiber, so it is necessary to efficiently separate the heavy metal catalyst from the NCA or NCA ester.

The method for recovering cobalt and manganese, which are the heavy metal catalysts used in the production of NCA, is as follows: In the production of terephthalic acid by liquid phase oxidation of p-xylene, the solvent is recovered from the filtrate from which the terephthalic acid produced is separated, and then the residual Method of recovering carbonate from carbonate
339, Japanese Patent Application Laid-open No. 47-34088), oxidation reaction by-products that are harmful to the oxidation reaction, which are recovered at the same time as the cobalt and manganese used, are oxidized again with molecular oxygen to remove them. How to restore activity (
JP 49-106986 A), 2,6-diitubropylnaphthalene or its oxidized intermediate, cobalt,
Crude 2,6-naphthalene dicarboxylic acid obtained by oxidation with molecular oxygen in the presence of a catalyst consisting of manganese and bromine is brought into contact with an aqueous mineral acid solution to elute the catalytic metal, and then alkali carbonate or alkali bicarbonate is added to this. A method for recovering metal catalysts as carbonates or bicarbonates by adding
-212345), or the crude crystals of aromatic carboxylic acid obtained by oxidizing the aromatic compound with molecular oxygen-containing gas in the presence of a heavy metal-containing catalyst in a lower aliphatic carboxylic acid solvent are washed with water. Alternatively, in addition to purification by recrystallization, a compound that generates carbonate ions is added to the washing liquid or recrystallization mother liquor, and the dissolved heavy metal catalyst is recovered as a water-insoluble carbonate (Japanese Patent Application Laid-Open No. 1121237).
Many other proposals have been made.

However, the recovery of the heavy metal catalysts described above is limited to crude N
Carbonate is recovered from the filtrate from which CA is separated, the washing solution from which crude NCA is washed or recrystallized, or the mother liquor.

[Problems to be Solved] The present invention uses a heavy metal catalyst during NCA production to cause an esterification reaction of NCA, and a filtrate obtained by filtering crude NCA ester from the obtained esterification reaction recovery product and/or a crude NCA ester. The object of the present invention is to provide a production method that eliminates the need for washing or recrystallization of crude NCA and obtains highly pure NCA ester by recovering it from the washed washing solution.

[Means for Solving the Problems] As a result of research on methods for recovering heavy metal catalysts used in NCA production and purifying NCA esters, the present inventors conducted an esterification reaction with NCA separated from a reaction solution after an oxidation reaction. The inventors have discovered that by washing the obtained crude NCA ester with water or an aqueous acid solution, if necessary, the heavy metal catalyst can be easily removed and recovered, and the purity of the NCA ester can be improved, and the present invention has been achieved.

That is, in the present invention, substituted naphthalene is treated in a solvent containing a lower aliphatic monocarboxylic acid in the presence of a heavy metal catalyst,
Crude NC containing heavy metal catalyst obtained by oxidation with molecular oxygen
A is esterified in an alkyl alcohol in the presence of an esterification catalyst, and then a filtrate obtained by filtering the esterification reaction recovered as necessary and/or an esterified product is mixed with water or an acid aqueous solution. or a cleaning solution obtained by washing with at least one kind of alkyl alcohol, or a concentrate thereof, a compound that generates carbonate ions is added, and the dissolved heavy metal catalyst is recovered as an insoluble carbonate. This is a method for producing NCA ester.

In this invention, the substituted naphthalene used as a raw material includes all isomers having one or more alkyl groups such as methyl, ethyl, and isopropyl groups, or acyl groups such as acetyl and formyl groups as substituents. can do.

Further, as the lower aliphatic monocarboxylic acid used as a solvent during NCA production, acetic acid, propionic acid, acetic acid, etc. can be used, but acetic acid is preferable. These can be used as they are, but they can also be mixed with oxidation-stable water or a hydrocarbon solvent such as chlorobenzene or bromobenzene.

As molecular oxygen, air, oxygen, or a mixture of oxygen and an inert gas can be used, but it is preferable to use air as it is.

Heavy metal catalysts include cobalt, manganese, nickel,
Any compound such as cerium, copper, iron or zinc that can be dissolved in an oxidizing solvent is sufficient, and lower fatty acid salts such as acetate are particularly preferred.

As the catalyst used for the esterification reaction of NCA, sulfuric acid, hydrochloric acid, phosphoric acid, toluenesulfonic acid, titanate esters such as tetraisopropyl titanate, metal sulfates such as bismuth sulfate, etc. can be used.

As the alkyl alcohol used for the esterification reaction of crude NCA or for washing the crude NCA ester, at least one of methyl alcohol, ethyl alcohol, propyl alcohol, butyl alcohol, or isomers thereof can be used.

Compounds that generate carbonate ions used for recovery of heavy metal catalysts from the filtrate obtained by filtration of the esterification reaction product and/or the washing liquid of the crude NCA ester include sodium carbonate, potassium carbonate, ammonium carbonate, and hydrogen carbonate. At least one of sodium and potassium hydrogen carbonate can be used.

The oxidation reaction conditions and the esterification reaction conditions may be those commonly used and are not particularly limited, but the reaction temperature during the esterification reaction is preferably 160°C or lower.

After the oxidation reaction, the crude NCA separated from the reaction product is
Although it contains heavy metal compounds, it can be used as is or after being washed with water, alkyl alcohol, etc., and then dried.
Alternatively, it can be supplied to the esterification reaction step without drying.

When the crude NCA ester containing heavy metal compounds filtered from the esterification reaction recovery product is washed with at least one of water, an aqueous acid solution, or an alkyl alcohol, the heavy metal compounds are dissolved and transferred into the washing solution. Can be separated with high yield.

As the acid aqueous solution to be used, an aqueous solution of sulfuric acid, hydrochloric acid, nitric acid, acetic acid, etc. can be used.

If a compound that generates carbonate ions is added to the washing solution in which heavy metal compounds are dissolved or to the filtrate after crude NCA ester separation, the dissolved heavy metal compounds will react with the carbonate ions and the insoluble carbonate It can be converted into a salt and easily recovered in high yield by means such as filtration.

When cleaning with an acid aqueous solution, the cleaning solution becomes neutralized as the amount of the compound that generates carbonate ions increases, changing from acidic to basic. Alternatively, a compound that generates carbonate ions can be added after neutralizing excess acid in the cleaning solution.

In this case, the pH after adding the compound that produces carbonate ions varies depending on the compound that produces carbonate ions, but is preferably 7.5 or higher.

The heavy metal compounds separated and recovered in this manner can be recycled as they are to the oxidation reaction step.

[Effects of the Invention] According to the method of the present invention, the heavy metal catalyst used in the oxidation reaction during NCA production can be recovered in high yield and recycled, and a highly pure NCA ester can be obtained. Therefore, it is extremely advantageous in industrial implementation.

[Example] An example of implementing this invention will be described below.
The invention is not limited to this example.

In the following examples, cobalt and manganese were analyzed by plasma emission spectrometry, and bromine was analyzed by ion chromatography.

Example 1 In a titanium autoclave with a capacity of 0.5E, cobalt acetate tetrahydrate 7.47 g, manganese acetate tetrahydrate 7.34 g, potassium bromide 7.14 g, potassium acetate 5.91 g, 230 g of acetic acid was charged as a solvent, and 62.70 g of 2.6-diitubropylnaphthalene was added over 4 hours while stirring and blowing in excess air at a reaction pressure of 30 kg/cm2・G and a reaction temperature of 200°C. After that, only air was blown in for 1 hour to complete the oxidation reaction. Insoluble matter was collected from the reaction product by filtration and dried to obtain 60.5 g of crude naphthalene dicarboxylic acid containing heavy metal compounds. When this was analyzed using gas chromatography, the yield of 2.6-naphthalenedicarboxylic acid was 87.2 mol% based on the amount of 2.6-diitupropylnaphthalene charged.

This crude naphthalene dicarphonic acid and methyl alcohol 600
g and 18 g of 96% sulfuric acid were charged into an autoclave manufactured by Hastelloy Co., Ltd., and an esterification reaction was carried out at a reaction temperature of 120° C. for 4 hours. After the reaction was completed, the esterification reaction product was filtered to separate and recover crude naphthalene dicarboxylic acid dimethyl ester containing heavy metal compounds. This crude naphthalene dicarboxylic acid dimethyl ester and water 7001 were placed in a beaker with a capacity of 1, and after stirring at room temperature for 30 minutes,
The solid matter was filtered and dried to obtain 61.5 g of a yellowish-white dimethyl naphthalene dicarboxylic acid ester.

This naphthalene dicarboxylic acid dimethyl ester had a cobalt concentration of 2.5 ppm and a manganese concentration of 6.4 ppm.

From 210 g of a filtrate obtained by filtering crude naphthalene dicarboxylic acid from the oxidation reaction product, acetic acid, water, etc. were distilled off using an evaporator to obtain 22.5 g of a solid. Furthermore, from the filtrate obtained by filtering the crude naphthalene dicarboxylic acid dimethyl ester from the esterification reaction product, methyl alcohol, water, etc. were similarly distilled off to obtain 3.7 g of a solid. These solids were mixed and dissolved in 100 g of water, and the insoluble matter was filtered out. Then, the washing water of the crude naphthalene dicarboxylic acid dimethyl ester was mixed, and a 15% aqueous sodium carbonate solution was added.
The mixture was added and stirred until H was 9 or more.

After the stirring was completed, the reddish-purple precipitate formed was filtered off and dried to obtain 8.05 g of a reddish-purple solid. Quantitative analysis of each heavy metal was performed, and the recovery rate of each heavy metal was 97.0% for cobalt and 965% for manganese based on the amount charged.

Then, 2,6-diitubrobylnaphthalene was oxidized using the recovered heavy metal catalyst under the same conditions as the oxidation reaction, but no decrease was observed in the yield of 2,6-naphthalene dicarboxylic acid. .

Example 2 61.0 g of crude naphthalene dicarboxylic acid produced in the same manner as in Example 1, 610 g of methyl alcohol, and 96
% sulfuric acid was charged into an autoclave manufactured by Hastelloy Co., Ltd., and an esterification reaction was carried out at a reaction temperature of 120° C. for 4 hours. After the reaction is completed, the esterification reaction product is filtered,
Crude naphthalene dicarboxylic acid dimethyl ester containing heavy metal compounds was separated and recovered. This crude naphthalene dicarboxylic acid dimethyl ester and 3% sulfuric acid aqueous solution 500 +
oe was placed in a beaker with a capacity of 1.00, and stirred at room temperature for 30 minutes.The solid matter was filtered out and dried to give 62.2 g of naphthalene dicarboxylic acid dimethyl ester of a yellowish white color.
I got it.

The cobalt concentration in this naphthalene dicarboxylic acid dimethyl ester is 0.5 ppm, and the manganese concentration is 1°1 p.
It was pm.

From 210 g of a filtrate obtained by filtering crude naphthalene dicarboxylic acid from the oxidation reaction product, acetic acid, water, etc. were removed using an evaporator to obtain 22.1 g of a solid. Similarly, methyl alcohol,
Water etc. are distilled off and it becomes solid! 4.0 g of 1IIJ was obtained. These solids were mixed and dissolved in 100 g of water, and the insoluble matter was filtered out. Then, the washed sulfuric acid aqueous solution of the crude naphthalene dicarboxylic acid dimethyl ester was mixed, and 15% sodium carbonate was added until the pH was 9 or higher. and stirred.

After the stirring was completed, the reddish-purple precipitate formed was filtered off and dried to obtain 8.1 g of a reddish-purple solid.

Quantitative analysis of each heavy metal was performed, and the recovery rate of each heavy metal relative to the amount charged was 97.5% for cobalt and 96.9% for manganese.

When 2,6-diitubropylnaphthalene was oxidized using the recovered heavy metal catalyst under the same conditions as the oxidation reaction, no decrease in the yield of 2,6-naphthalene dicarboxylic acid was observed.

Claims (6)

[Claims] (1) Substituted naphthalene was oxidized with molecular oxygen in the presence of a heavy metal catalyst in a solvent containing a lower aliphatic monocarboxylic acid. Crude naphthalenecarboxylic acid containing a heavy metal catalyst was oxidized with an esterification catalyst in an alkyl alcohol. A cleaning solution obtained by washing the esterified product obtained by filtering the esterification reaction product in the presence of esterification and then filtering the esterification reaction product, which is carried out as necessary, with at least one of water, an aqueous acid solution, or an alkyl alcohol, and/or a compound that generates carbonate ions is added to the filtrate obtained by filtration of the esterification reaction product or a concentrate thereof, and the dissolved heavy metal catalyst is recovered as an insoluble carbonate. A method for producing naphthalene carboxylic acid ester. (2) Substituted naphthalene has 1 alkyl group or acyl group
The method according to claim 1, characterized in that the method comprises at least one. (3) The method according to claim 1 or 2, characterized in that at least one of a cobalt compound, a manganese compound, a nickel compound, a copper compound, a cerium compound, an iron compound, or a zinc compound is used as the heavy metal catalyst. (4) The method according to any one of claims 1 to 3, characterized in that at least one of sulfuric acid, hydrochloric acid, phosphoric acid, and toluenesulfonic acid is used as the esterification catalyst. (5) As the alkyl alcohol, methyl alcohol,
Ethyl alcohol or propyl alcohol, butyl alcohol or at least one of these isomers
5. The method according to claim 1, characterized in that seeds are used. (6) The method according to any one of claims 1 to 5, characterized in that the acid aqueous solution is at least one aqueous solution of sulfuric acid, hydrochloric acid, nitric acid, or acetic acid. (7) The compound that produces carbonate ions is sodium carbonate. 7. The method according to claim 1, characterized in that at least one of potassium carbonate, ammonium carbonate, sodium bicarbonate or potassium bicarbonate is used.