JPH07107022B2 - Method for producing aromatic polycarboxylic acid - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing diphenylsulfone polycarboxylic acid or diphenyl ether polycarboxylic acid.

Diphenyl sulfone polycarboxylic acid or diphenyl ether polycarboxylic acid produced by the present invention is a polyimide, polyamide, polyester, polyamideimide,
It can be used as a raw material for various resins such as polyesterimide, a modifier, a curing agent for epoxy resins, and a raw material for agricultural chemicals and dyes, and has a wide range of applications.

Conventional technology Conventionally, 3,3′4,4′-tetramethyldiphenyl sulfone and
The oxidation of 3,3′4,4′-tetramethyldiphenyl ether with molecular oxygen produces diphenylsulfone-3,
3'4,4'-tetracarboxylic acid or diphenyl ether-3,
It is well known that 3'4,4'-tetracarboxylic acid can be obtained. However, for example, in the case of oxidizing 3,3′4,4′-tetramethyldiphenyl sulfone, known methods include using expensive and corrosive trifluoroacetic acid or trichloroacetic acid as a part of the solvent (Khim. Moscow], (5), 393,
(1974)), with or (USSR combustion of a large amount of acetic acid for requiring high temperature and high pressure, 422,730), and the reaction is not complete (Chem.Abstr., 76, 59282) and the like, either method industrially satisfactory Can not.

On the other hand, regarding the oxidation of 3,3′4,4′-tetramethyldiphenyl ether, there has been a previous report (Chem. Abstr., 82 , 16487,
Chem. Abstr., 82 , 124995), the yield of the target diphenyl ether-3,3'4,4'-tetracarboxylic acid is as low as 60% or less, which is a practical problem.

The inventors of the present invention oxidize all diphenyl sulfones or diphenyl ethers having at least one phenyl group having one or more adjacent alkyl groups with molecular oxygen to convert all of the alkyl groups to carboxyl groups, and obtain the corresponding diphenyl sulfones. In producing a polycarboxylic acid or diphenyl ether polycarboxylic acid, the inventors have made earnest studies to establish an advantageous method for solving the drawbacks of the conventional methods.

As a result, by carrying out the reaction in the presence of a specific catalyst and a specific aliphatic carboxylic acid in the presence of a specific amount of water, an expensive solvent is not required and the reaction can be performed under mild conditions, and the aliphatic Based on this finding, it was found that the desired diphenylsulfone polycarboxylic acid or diphenyl ether polycarboxylic acid can be obtained with extremely low carboxylic acid combustion and an extremely high yield, and the intended purpose can be achieved. Was completed.

That is, the present invention provides a novel and industrially advantageous production method of diphenylsulfone polycarboxylic acid or diphenyl ether polycarboxylic acid having at least one phenyl group and one or more adjacent alkyl groups. is there.

Means for Solving the Problems A method for producing diphenylsulfone polycarboxylic acid or diphenyl ether polycarboxylic acid according to the present invention is a diphenyl sulfone or diphenyl ether having at least one phenyl group and one or more adjacent alkyl substituents. With an oxygen or oxygen-containing gas in the presence of a catalyst consisting of a combination of a bromine compound of two or more heavy metals selected from the group consisting of cobalt, manganese and cerium in an aliphatic monocarboxylic acid having 2 to 10 carbon atoms. When the corresponding diphenyl sulfone polycarboxylic acid or diphenyl ether polycarboxylic acid is produced by oxidation, the reaction is carried out in the presence of 1 to 50% by weight of water with respect to the aliphatic monocarboxylic acid.

The alkyl-substituted diphenyl sulfones and alkyl-substituted diphenyl ethers used as raw materials in the present invention are
Diphenyl sulfones or diphenyl ethers having at least one phenyl group having one or more adjacent alkyl groups, and the alkyl group has 1 to 5 carbon atoms, and a methyl group, an ethyl group, and a propyl group are particularly preferable.
Specifically, for example, 3,4-dimethyldiphenyl sulfone, 3,4,4'-trimethyldiphenyl sulfone, 3,3'4,
4'-tetramethyldiphenyl sulfone, 2,3'4'-trimethyldiphenyl sulfone, 2,3,4'-trimethyldiphenyl sulfone, 2,3,3 ', 4'-tetramethyldiphenyl sulfone, 2,2', 3,3'-tetramethyldiphenyl sulfone, 2,4,5-trimethyldiphenyl sulfone, 2,
4,4'5-tetramethyldiphenyl sulfone, 2,3'4,
4 ', 5-pentamethyldiphenyl sulfone, 2,2', 4,
4 ', 5,5'-hexamethyldiphenyl sulfone, 3,3'-
Dimethyl-4,4'-diethyldiphenyl sulfone, 3,3 '
-Dimethyl-4,4'-dipropyldiphenyl sulfone,
3,4-dimethyldiphenyl ether, 3,4,4'-trimethyldiphenyl ether, 3,3'4,4'-tetramethyldiphenyl ether, 2,3 ', 4'-trimethyldiphenyl ether, 2,3,4'-trimethyldiphenyl ether , 2,
3,3 ′, 4′-tetramethyldiphenyl ether, 2,2 ′,
3,3'-tetramethyldiphenyl ether, 2,4,5-trimethyldiphenyl ether, 2,4,4'5-tetramethyldiphenyl ether, 2,3 ', 4,4'5-pentamethyldiphenyl ether, 2,2', 4,4 ', 5,5'-hexamethyldiphenyl ether, 3,3'-dimethyl-4,4'-diethyldiphenyl ether, 3,3'-dimethyl-4,4'-dipropyldiphenyl ether and the like can be mentioned.

The catalyst according to the present invention comprises a combination of a bromine compound and two or more heavy metals selected from the group consisting of cobalt, manganese and cerium. These heavy metals are elemental,
Any form of oxide, salt, or complex may be used. On the other hand, as the bromine compound, any of a bromine molecule, an acid, a salt, an oxygen salt or an organic bromine compound can be used. Particularly preferred are hydrogen bromide, ammonium bromide, cobalt manganese bromide, cerium bromide, tetrabromoethane, tribromoethane and the like.

The combination of two or more of cobalt, manganese, cerium and nickel with a bromine compound has advantages such as elimination of induction period and high reaction rate. Such combinations include, for example, cobalt bromide and manganese bromide, cobalt bromide and manganese acetate, cobalt acetate and manganese bromide, manganese acetate and cobalt acetate and ammonium bromide, cobalt acetate and manganese acetate and hydrogen bromide, Cobalt bromide and cerium acetate, cobalt acetate and cerium bromide, manganese bromide and cerium acetate, cobalt acetate and manganese acetate and cerium acetate and ammonium bromide, cobalt naphthenate and manganese naphthenate and tetrabromoethane, cobalt acetylacetate And manganese acetylacetonate and hydrogen bromide. in this case,
It is preferable that each heavy metal compound is contained in an amount of at least 0.1% by weight in terms of metal.

The total amount of heavy metals is suitably 0.05 to 10 g / metal equivalent concentration. If the reaction rate is less than 0.05g /
If it is more than g /, the burden of catalyst cost will increase and it will be difficult to purify the target product.

The amount of bromine compound used is 0.1 g / to 50 g / in terms of bromine atom.
Is appropriate. If it is 0.1 g / g or less, a sufficient reaction rate cannot be obtained, and if it is 50 g / g or more, bromine undesirably contaminates the target substance and burdens the catalyst cost.

In addition, the present reaction method uses aliphatic corbonic acid as a reaction solvent and a reaction accelerator. A saturated monocarboxylic acid having 2 to 10 carbon atoms is exemplified as one which is relatively stable against oxidation and can be easily separated from the reaction product, and acetic acid is particularly preferable. The amount used depends on the type of raw material and other reaction conditions, but is 50 to 900 g.
It is preferably /.

The method of the present invention is characterized by allowing a specific amount of water to coexist from the initial stage of the reaction.

The amount of water to coexist is 1 to 50 relative to saturated monocarboxylic acid.
%, Preferably 2 to 30% by weight. When it is 1% by weight or less, the loss of the aliphatic carboxylic acid due to oxidation is large, and the yield of the target diphenylsulfone polycarboxylic acid or diphenyl ether polycarboxylic acid is low. On the contrary, if the amount is 50% by weight or more, the reaction hardly progresses.

The molecular oxygen used as the oxidant can be used as pure oxygen or industrial exhaust gas, but industrially normal air is most suitable.

The reaction temperature is in the range of 100 to 200 ° C, more preferably 150 to 190 ° C.

The reaction pressure is such that the total reaction pressure is 1 to 30 Kg / cm ² G, especially 3 to 20 K.
It is preferably g / cm ² G and an oxygen partial pressure of 0.01 to 2.4 Kg / cm ² .
In particular, from the viewpoint of safety, it is desirable to operate so that the oxygen concentration in the exhaust gas is 8% by volume or less.

The method of the present invention is generally carried out as follows.

That is, an alkyl-substituted diphenyl sulfone or an alkyl-substituted diphenyl ether as a raw material, a catalyst, an aliphatic carboxylic acid and water are charged into a reactor equipped with a stirrer equipped with a gas inlet and a gas outlet, and substituted or pressurized with a gas containing nitrogen or oxygen. , Heat to a predetermined temperature. Stirring and gas blowing are not always necessary in this temperature rising process.

Depending on the type of catalyst, the absorption of oxygen is generally 100-1
Starts at 50 ° C. When the absorption of oxygen starts, oxygen or an oxygen-containing gas is introduced, and the reaction is performed while maintaining the oxygen partial pressure and concentration within a predetermined range.

The exhaust gas is cooled and the condensate is returned to the reactor.

After the reaction for a predetermined time, it is cooled, the reaction product is taken out, and the target diphenyl sulfone polycarboxylic acid or diphenyl ether polycarboxylic acid is crystallized as it is or by distilling off a part of the aliphatic carboxylic acid and water, After removing the group carboxylic acid and water by distillation, the crystals are recrystallized with a solvent and taken out.

A bubble column system can also be adopted as the reactor other than the above-mentioned one equipped with a stirrer.

The reaction method is not limited to the batch reaction, and a continuous or semi-continuous method is also possible. Specifically, the raw material, the catalyst, the aliphatic monocarboxylic acid and water are continuously supplied to the reactor to carry out the reaction while blowing oxygen or an oxygen-containing gas, and the reaction product is continuously withdrawn or fed to the reactor. A catalyst, an aliphatic monocarboxylic acid and water were charged, and then (1) only raw materials or (2)
Examples include a method in which the raw material and the aliphatic monocarboxylic acid or (3) the raw material, the aliphatic monocarboxylic acid, and water are charged and reacted for a certain period of time, then the charging is stopped and the reaction is continued to complete the reaction.

EXAMPLES Hereinafter, the present invention will be described in detail with reference to Examples.

Example 1 In a titanium autoclave equipped with a stirrer and having a volume of 500 ml, which was equipped with a gas inlet and a gas outlet with a reflux condenser,
3 ', 4,4'-tetramethyldiphenyl sulfone (hereinafter "T
Abbreviated as MS ") 90 g, cobalt bromide _{[CoBr 2 · 6H 2 O]} 2.
8g and manganese acetate _{[Mn (OCOCH 3) 2 ·} 4H 2 O] 0.5g, was charged with acetic acid 200g and water 10 g, nitrogen was pressed 10 Kg / cm ² G until pressurized and heated with stirring. At the reaction temperature of 140 ° C, air is introduced, and acetic acid that evaporates by the cooler at the gas outlet is refluxed to discharge the exhaust gas.
The amount of introduced air was adjusted so that the oxygen concentration in the exhaust gas was in the range of 1 to 6% at 15 kg / cm ² G (oxygen partial pressure 0.1 to 0.8 at).
m). After reacting for about 2.5 hours under these conditions, no absorption of oxygen was observed. At this point, the introduction of air was stopped and the reaction was continued for another 30 minutes. Cool the reactor and remove the contents,
Acetic acid and water were distilled off under reduced pressure to obtain 134 g of a crude product of the oxidation reaction.

The neutralization number of this product was 545, and as a result of HPLC analysis and GLC analysis, the purity of the target diphenylsulfone-3,3 ', 4,4'-tetracarboxylic acid (hereinafter abbreviated as "DSTA") was 9
It was 6.5% and the yield was 98.9%. The degree of oxidative decomposition of the acetic acid used (combustion rate of acetic acid) was calculated from the amount of carbon dioxide in the exhaust gas.
%Met.

Examples 2-3 Under the same conditions as in Example 1, the amount of water charged was changed.
Produced DSTA. Here, as the catalyst, cobalt acetate _{[Co (OCOCH 3) 2 ·} 4H 2 O] 2.5g, manganese acetate [Mn (OC
_{OCH 3) 2 · 4H 2 O} ] 2.7g, using ammonium bromide 3.7 g. The results obtained are shown in Table 1.

Examples 4 to 7 In the same reactor as in Example 1, 90 g TMS, 200 g acetic acid and 10 g water.
And a predetermined amount of various catalysts shown in Table 2 were charged at a reaction temperature.
170-180 ° C., a pressure 10Kg / cm ² G (oxygen partial pressure 0.005~0.6at
DSTA was produced under the conditions of m). The results obtained are shown in Table 2.

Example 8 In the same reactor as in Example 1, 60 g of 3,4,4'-trimethyldiphenyl sulfone, 225 g of acetic acid, 15 g of water, 2.3 g of cobalt acetate as a catalyst, 4.8 g of manganese acetate and ammonium bromide.
3.7 g was charged and reacted at 170 to 180 ° C. under 10 Kg / cm ² for 2.5 hours to obtain diphenylsulphone-3,4,4′-tricarboxylic acid in a yield of 97.8%.

Example 9 In the same manner as in Example 8, 3,3 ′, 4,4′-tetramethyldiphenyl ether was used as a raw material and reacted at 180 to 190 ° C. and 20 Kg / cm ² for 3.5 hours to conduct diphenyl ether-3, 3'4,
4'-Tetracarboxylic acid was obtained in a yield of 92.1%.

Example 10 2,3,3 ', 4'-Tetramethyldiphenylsulfone was used as a starting material and reacted in the same manner as in Example 9 to obtain diphenylsulfone-2,
3,3 ', 4'-Tetracarboxylic acid was obtained in a yield of 97.5%.

Example 11 In the same manner as in Example 8, 3,4-diethyldiphenyl ether was used as a raw material and reacted at 160 to 170 ° C. and 10 Kg / cm ² for 2.5 hours to give 9% of diphenyl ether-3,4-dicarboxylic acid.
Obtained in a yield of 5.3%.

Comparative Example 1 The type of catalyst and its concentration were the same as in Example 2, and DSTA was produced in a system containing no water. The obtained results are first
Shown in the table.

Comparative Example 2 The type of catalyst and its concentration were the same as in Example 2, and DSTA was produced in a system in which water was excessively blended. The results obtained are shown in Table 1.

USSR Comparative Example 3 catalyst, using the following catalysts according to _{422,730, Co (OCOCH 3) 2} · 4H 2 O 1.0g Mn (OCOCH 3) 2 · 4H 2 O 1.0g Ni (OCOCH 3) 2 · 4H _When 90 g of ₂ O 1.0 g NH ₄ Br 1.6 g TMS was reacted in 200 g of acetic acid at 200 ° C. under the conditions of 30 kg / cm ² for 5 hours, DSTA was obtained in a yield of 91.3%. The acetic acid combustion rate at this time was 13%.

EFFECTS OF THE INVENTION According to the present invention, a corresponding diphenylsulfone polycarboxylic acid or diphenyl ether polycarboxylic acid is obtained by oxidizing diphenyl sulfone or diphenyl ether having at least one phenyl group having one or more adjacent alkyl substituents under mild conditions. Can be produced in a high yield, and the loss due to the oxidation of the aliphatic monocarboxylic acid used in combination can be reduced.

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Claims (1)

[Claims] 1. A diphenyl sulfone or diphenyl ether having at least one phenyl group and one or more sets of adjacent alkyl substituents is oxidized with oxygen or an oxygen-containing gas in an aliphatic monocarboxylic acid having 2 to 10 carbon atoms. In producing the corresponding diphenyl sulfone polycarboxylic acid or diphenyl ether polycarboxylic acid, the aliphatic group in the presence of a catalyst composed of a combination of two or more heavy metals selected from the group consisting of cobalt, manganese and cerium and a bromine compound is used. A method for producing diphenylsulfone polycarboxylic acid or diphenyl ether polycarboxylic acid, which comprises reacting with monocarboxylic acid in the presence of 1 to 50 parts by weight of water.