JP2003342228A - Method for producing biphenyltetracarboxylic acid - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for inexpensively and efficiently producing a biphenyltetracarboxylic acid. <P>SOLUTION: This method for producing the biphenyltetracarboxylic acid comprises oxidizing a tetraalkylbiphenyl with an oxygen-containing gas in the presence of a catalyst containing a heavy metal and bromine and a reaction solvent. The reaction is carried out at 80-170°C. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing biphenyltetracarboxylic acid (hereinafter abbreviated as BPTA). BPTA is used as a polyimide resin with a useful function that has never been obtained using the anhydride obtained from this as a raw material.
Or polyester resin modifier, epoxy resin curing agent, special plasticizer raw material, medical / agrochemical raw material, lubricant oil raw material, etc.
Has a wide range of uses.

[0002]

2. Description of the Related Art Conventionally, BPTA is known to be obtained by dehalogenation dimerization of nuclear halogenated phthalic acids. For example, Japanese Examined Patent Publication No. 05-3857 describes that BPTA is obtained by dehalogenation dimerization of nuclear halogenated phthalic acids with a palladium catalyst, an alkali hydroxide compound and a reducing agent such as a polyhydric alcohol. . Further, a method for obtaining BPTA by oxidizing tetramethylbiphenyl is described in JP-A-48-54048 and JP-A-61-22045.

[0003]

However, the conventional
The BPTA process is not fully satisfactory. For example, the manufacturing method described in Japanese Examined Patent Publication No. 05-3857 is based on dehalogenation 2
The quantification produces twice as much salt as the product, and the discharged salt poses a serious problem to the environment, which imposes a great economic burden on the treatment. The production method described in JP-A-48-54048 uses acetic acid as a solvent and a reaction temperature of 20.
The oxidation reaction is carried out with air at 0 ° C, but the yield is insufficient. The method using nitric acid as an oxidant described in the same patent produces a large amount of toxic nitrogen oxides as a by-product although the yield is high, and a heavy burden is imposed on the treatment of the nitrogen oxides. An object of the present invention is to provide a method for producing biphenyltetracarboxylic acid inexpensively and efficiently.

[0004]

[Means for Solving the Problems] In order to solve the above problems, the present inventors have made extensive studies on a method for producing BPTA by oxidation of tetraalkylbiphenyl. as a result,
The inventors have found that the yield of BPTA can be improved by appropriately selecting the reaction temperature of the oxidation reaction in a specific catalyst system, and have reached the present invention. That is, the present invention is a method for producing a biphenyltetracarboxylic acid by oxidizing a tetraalkylbiphenyl with an oxygen-containing gas in the presence of a catalyst containing a heavy metal and bromine, and a reaction solvent, and a reaction temperature of 80 to 170. A method for producing biphenyltetracarboxylic acid characterized in that the temperature is in the range of ° C.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The tetraalkylbiphenyl as an oxidizing raw material used in the present invention includes 3,4,3 ', 4'-tetramethylbiphenyl and 2,3,3', 4'-tetramethylbiphenyl. , 2,3,2 ', 3'-tetramethylbiphenyl, 3,4,3', 4'-tetraethylbiphenyl, 3,4-dimethyl, 3 ', 4'-diethylbiphenyl and the like. These raw materials are, for example,
It can be made from dialkylbenzene by oxidative coupling using Pd as a catalyst. It can also be produced by dehalogenation dimerization of a halogenated dialkylbenzene. The tetraalkylbiphenyl produced by these production methods has a mixture of several kinds of isomers, which can be easily separated by distillation or crystallization. It is also possible to partially oxidize the alkyl groups of these raw materials and then use the raw materials of the present invention.

In the present invention, the oxidation reaction is carried out under the liquid phase condition using a solvent. As the solvent, a lower aliphatic carboxylic acid is preferable, and an aliphatic monocarboxylic acid having 1 to 5 carbon atoms is more preferable. Specific examples thereof include formic acid, acetic acid, propionic acid, butyric acid, etc. These can be used alone or as a mixture. Of these, acetic acid and propionic acid are preferable, and acetic acid is particularly preferable. The water content of the solvent used is 1 to 70
% By weight, preferably 5 to 50% by weight. If the water concentration is too low, the metal content in BPTA will increase. If the water concentration is too high, the reaction rate becomes slow and the yield decreases. The amount of the solvent used is usually 1 to 20 times by weight, preferably 2 times the weight of the starting tetraalkylbiphenyl.
10 to 10 times by weight.

The catalyst used in the present invention contains a heavy metal and bromine, and is a combination of a bromine compound and one or more metals selected from the group consisting of cobalt, manganese, nickel, cerium, iron and zirconium. It is a thing. Preferably cobalt, manganese, nickel,
It is a combination of two or more metals selected from the group consisting of zirconium and a bromine compound. Cobalt source,
Examples of the manganese source, nickel source, cerium source, iron source and zirconium source include metal compounds such as organic acid salts, halides and carbonates, and acetate and bromide are particularly preferable. Any bromine compound may be used as long as it dissolves in the reaction system and generates bromine ions.Inorganic bromide such as hydrogen bromide, sodium bromide, cobalt bromide and manganese bromide, organic such as tetrabromoethane, etc. Examples of the bromide include hydrogen bromide, cobalt bromide and manganese bromide.

The amount of the catalyst metal used in the present invention is in the range of 0.03 to 2% by weight, preferably 0.05 to 1% by weight, as the total metal concentration in the solvent. If the total metal concentration is too low, the reaction does not proceed sufficiently and the reaction intermediate is mainly produced. If the total metal concentration is too high, the catalyst cost will deteriorate and the amount of metal mixed into BPTA will increase. The bromine ion concentration in the solvent is 0.01 to 2% by weight, preferably 0.03 to
It is in the range of 1% by weight. If the bromine ion concentration is too low, the reaction does not proceed, and if the bromine ion concentration is too high, BP is formed.
The bromine content of TA becomes high, and the corrosion of the equipment becomes severe.
The ratio (weight ratio) of the total catalyst heavy metal concentration to the bromine ion concentration is in the range of 0.1 to 10, preferably 0.2 to 5. The catalyst metal and the bromine compound may all be supplied at the starting amount of the reaction, or may be divided and supplied separately at the beginning and the end of the reaction, respectively.

An oxygen-containing gas is used for the liquid phase oxidation of the present invention. Examples of the oxygen-containing gas include oxygen gas and air, and a gas obtained by mixing these with an inert gas such as nitrogen or argon. Air is industrially advantageous. A stirring tank, a bubble column, or the like is used as the oxidation reactor, and the stirring tank is preferable in order to sufficiently stir the inside of the reactor. A batch type, a semi-batch type or a continuous type is preferably used as the reaction type. In the batch system and the semi-batch system, in order to complete the oxidation reaction, 5-9 after stopping the supply of the raw materials
It is preferable to continue supplying the oxygen-containing gas for 0 minutes. In the continuous system, it is preferable to provide a plurality of reactors in series in order to increase the reaction yield.

In the present invention, the reaction temperature for liquid phase oxidation is in the range of 80 to 170 ° C. If the reaction is carried out at a temperature higher than this range, the production of high-boiling substances will increase and the yield of BPTA will be significantly reduced. On the other hand, when the amount is lower than this range, the oxidation reaction is not completed and a large amount of intermediate remains, resulting in a decrease in yield. In the oxidation reaction, an oxygen-containing gas is continuously supplied to the reactor, and the gas after the reaction is continuously withdrawn from the reactor so as to have a pressure of 0.1 to 3 MPaG, preferably 0.3 to 2 MPaG. The oxygen concentration in the exhaust gas from the reactor is 0.1 to 8% by volume, preferably 1 to 5% by volume.

A reflux condenser is provided in the reactor so that a large amount of solvent entrained in the exhaust gas and water produced by the oxidation reaction are aggregated. The coagulated solvent and water are usually refluxed to the reactor, but a part of the solvent and water may be withdrawn to the outside of the reaction system in order to adjust the water concentration in the reactor. The residence time of the reaction solution in the reactor is usually in the range of 0.3 to 5 hours. When a plurality of reactors are provided in series, the total residence time falls within this range.

The oxidation reaction mixture is cooled within a temperature range of 10 to 120 ° C., preferably 20 to 50 ° C. to precipitate crude BPTA crystals. Crystallization can be performed in a batch system, a semi-batch system, or a continuous system. In the case of the continuous system, the crystal grain size becomes large and separation from the mother liquor becomes easy by carrying out in a multi-stage crystallization tank. The crystals obtained are separated from the reaction mixture by filtration or centrifugation. The separated crude crystals of BPTA are reslurry washed or rinsed with water or hydrous acetic acid to remove the reaction mother liquor.

In the present invention, at least part of the reaction mother liquor obtained by solid-liquid separation of the liquid-phase oxidation reaction product can be reused for the liquid-phase oxidation reaction. The reaction mother liquor contains high boiling by-products and the like, but in order to prevent these from accumulating and adversely affecting the reaction, the reuse ratio for the oxidation reaction should be 90% by weight or less of the reaction mother liquor. It is preferably 60% by weight or less. In order to carry out the reaction favorably, it is preferable to distill a part of the reaction mother liquor in order to remove the reaction product water before reuse in the oxidation reaction.
At this time, water may be extracted from the top of the tower to reduce the water content to 1 to 70% by weight, preferably 5 to 50% by weight.

In the present invention, the liquid phase oxidation reaction is 1 to 7
Since a lower aliphatic carboxylic acid solvent containing 0% by weight of water and a catalyst liquid consisting of heavy metals and bromine are used, in the production equipment that carries out the oxidation reaction, ordinary corrosion-resistant materials such as SUS304 and 316 are used for corrosion such as pitting corrosion. May occur. In order to solve such a problem, in the present invention, it is preferable that the surface of the reactor for the oxidation reaction is Ti or Zr coated with an oxide film. Ti or Zr whose surface is coated with oxide film
Is used for the main part of the apparatus, the oxidation reaction can be performed without causing corrosion such as pitting corrosion. As a device that requires Ti or Zr coated with an oxide film on the surface,
Equipment such as reactor, stirrer, etc. where catalyst liquid and reaction liquid may come in contact with each other at high temperature, and oxidation reaction off-gas line,
Examples include cooling heat exchangers and scrubbers.

The BPTA produced in the present invention can be dehydrated by a known method to form an anhydride. As a method of dehydration, BPTA is dissolved or slurried in acetic anhydride or a mixture of acetic acid and acetic anhydride in the range of SR1 to 20, and 0.2 to 10 hours in the temperature range of 70 to 230 ° C, preferably 80 to 130 ° C. .The method of heating or the method of heating at a temperature of 240 ° C. or higher in a nitrogen atmosphere, and 0.2% at a temperature of 200 ° C. or higher while dehydrating as necessary in a substantially water-insoluble organic solvent such as xylene. A method of heating for 10 hours.

[0016]

The present invention will be described in detail with reference to the following examples. However, the present invention is not limited to these examples. The yield of the target substance in each example is
It was calculated from the result of gas chromatography analysis of the reaction product.

Example 1 A 500 mL titanium autoclave equipped with a gas discharge pipe with a reflux condenser, a gas introduction pipe, and a stirrer was used as an apparatus. This equipment has 3,4,3 ', 4'-tetramethylbiphenyl 4
0 g, 47 wt% hydrogen bromide aqueous solution 1.5 g, manganese acetate tetrahydrate 0.86 g, cobalt acetate tetrahydrate 1.6 g,
Charge 228 g of acetic acid and 10 g of water, and in a nitrogen atmosphere,
While stirring, raise the pressure to 1.9 MPaG and the temperature to 140 ° C.
The temperature was raised. The amount of introduced air was adjusted so that the oxygen concentration was 1 to 6% while maintaining the reaction temperature at 140 to 145 ° C. After starting the introduction of air and reacting for 30 minutes, the reaction temperature was raised to 160 ° C. and the reaction was completed for 20 minutes under these conditions to complete the reaction. Table 1 shows the analysis results.

Example 2 In the same manner as in Example 1, 40 g of 3,4,3 ', 4'-tetramethylbiphenyl, 2.5 g of 47% by weight aqueous solution of hydrogen bromide, 0.86 g of manganese acetate tetrahydrate. , 2.4 g of nickel acetate tetrahydrate, 228 g of acetic acid and 10 g of water were charged and reacted. Table 1 shows the analysis results.

Example 3 In the same apparatus as in Example 1, 40 g of 3,4,3 ', 4'-tetramethylbiphenyl, 1.5 g of 47% by weight aqueous hydrogen bromide solution, and 0.86 g of manganese acetate tetrahydrate were added. , 1.6 g of cobalt acetate tetrahydrate, 228 g of acetic acid and 10 g of water were charged. In a nitrogen atmosphere, with stirring, the pressure is 1.9 MPaG and the temperature is 16
The pressure was raised to 0 ° C and the temperature was raised. The reaction temperature was constant at 160 ° C., and the reaction was carried out for 60 minutes while adjusting the amount of introduced air so that the oxygen concentration was 1 to 6%. Table 1 shows the analysis results.

Example 4 In the same apparatus as in Example 1, 1.5 g of 47% by weight aqueous solution of hydrogen bromide, 0.86 g of manganese acetate tetrahydrate, 1.6 g of cobalt acetate tetrahydrate, 228 g of acetic acid and water were added. Charge 10 g, and under a nitrogen atmosphere with stirring, pressure 1.9 MPaG,
The temperature was raised to 140 ° C and the temperature was raised. Reaction temperature 140-1
Maintained at 45 ℃, 3,4,3 ', 4'-tetramethylbiphenyl 4
While continuously supplying 0 g to the reactor for 30 minutes, the amount of introduced air was adjusted so that the oxygen concentration was 1 to 6%. 3,4,
After the supply of 3 ′, 4′-tetramethylbiphenyl was completed, the reaction temperature was raised to 160 ° C. and the reaction was allowed to complete for 20 minutes under these conditions. Table 1 shows the analysis results.

Comparative Example 1 In the same apparatus as in Example 1, 40 g of 3,4,3 ', 4'-tetramethylbiphenyl, 1.5 g of 47 wt% hydrogen bromide aqueous solution, 0.86 g of manganese acetate tetrahydrate, Cobalt acetate tetrahydrate 1.
6 g, 228 g of acetic acid and 10 g of water were charged, and the pressure was increased to 1.9 MPaG and the temperature was raised to 200 ° C. with stirring under a nitrogen atmosphere. The reaction was performed for 60 minutes after starting the introduction of air while adjusting the amount of introduced air so that the oxygen concentration was 1 to 6%. Table 1 shows the analysis results.

Comparative Example 2 In the same manner as in Comparative Example 1, 2.5 g of 47 wt% hydrogen bromide aqueous solution, 0.86 g of manganese acetate tetrahydrate, 2.4 g of nickel acetate tetrahydrate, 228 g of acetic acid and water. 10 g was charged and reacted. The results are shown in Table 1.

[0023]

[Table 1]

[0024]

As is apparent from the above examples, the present invention enables the efficient production of biphenyltetracarboxylic acid at low cost.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hiroshi Ogawa             3-10 Mizushima Kaigan Dori, Kurashiki City, Okayama Prefecture             Ryo Gas Chemical Co., Ltd. Mizushima Plant F-term (reference) 4H006 AA02 AC46 AD15 AD17 BA08                       BA10 BA16 BA19 BA20 BA21                       BA37 BA82 BB17 BB31 BB47                       BC10 BC36 BD32 BD53 BE30                       BJ50 BS30                 4H039 CA65 CC30

Claims (8)

[Claims] 1. A method for producing a biphenyltetracarboxylic acid by oxidizing a tetraalkylbiphenyl with an oxygen-containing gas in the presence of a catalyst containing a heavy metal and bromine, and a reaction solvent, wherein the reaction temperature is 80 to 170. A method for producing biphenyltetracarboxylic acid, which is in the range of ° C. 2. A tetraalkylbiphenyl is 3,4,3 ′, 4′-
The biphenyltetracarboxylic acid according to claim 1, which is one or more compounds selected from tetramethylbiphenyl, 2,3,3 ', 4'-tetramethylbiphenyl and 2,3,2', 3'-tetramethylbiphenyl. Acid manufacturing method. 3. The heavy metal is cobalt, manganese, nickel,
The method for producing biphenyltetracarboxylic acid according to claim 1, which is one or more metals selected from the group consisting of cerium, iron and zirconium. 4. The bromine ion concentration in the solvent is 0.01 to 2% by weight, and the total catalyst heavy metal concentration in the solvent is 0.03 to 2%.
The method for producing biphenyltetracarboxylic acid according to claim 1, wherein the ratio of the total catalyst heavy metal concentration to the bromine ion concentration (weight ratio) is in the range of 0.1 to 10% by weight. 5. The method for producing biphenyltetracarboxylic acid according to claim 1, wherein the reaction solvent is a lower aliphatic carboxylic acid solvent containing 1 to 70% by weight of water. 6. The method for producing biphenyltetracarboxylic acid according to claim 1, wherein the amount of the reaction solvent used is 1 to 20 times by weight the amount of tetraalkylbiphenyl. 7. The method for producing biphenyltetracarboxylic acid according to claim 1, wherein the reaction product is crystallized from the oxidation reaction liquid and solid-liquid separated. 8. The method for producing biphenyltetracarboxylic acid according to claim 7, wherein at least a part of the reaction mother liquor obtained by solid-liquid separation of the reaction product is reused in the liquid phase oxidation reaction.