JPH0329778B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a novel para-terphenyltetracarboxylic acid or dianhydride thereof and a method for producing the same.

[Conventional technology]

Conventionally, aromatic tetracarboxylic acids or dianhydrides thereof include pyromellitic acid or dianhydrides,
Benzophenonetetracarboxylic dianhydride and the like are known, and are mainly known as raw materials for polyimide resins.

In addition, as terphenyltetracarboxylic acid, West German Patent Publication No. 2100391, British Patent No.
Para-terphenyl-2,3,2″,3″-tetracarboxylic acid represented by the formula [] described in specification No. 1338932 and US Patent No. 3891633
2,3: 2″,3″-dianhydride is known.

The tetracarboxylic dianhydride represented by the formula [] is a compound synthesized by the route shown by the following reaction formula [].

That is, an intermediate compound is obtained by a Diels-Alder reaction between 1,4-bis(α.furano)benzene and two molecules of maleic anhydride, and this is further dehydrated with concentrated sulfuric acid or polyphosphoric acid to form a tetracarboxylic acid. In this method, the nature of the reaction and the position of the acid anhydride group are determined by the 2,3-position and the 2″-3″-position.
It is the rank.

The compound represented by the formula [] is used as a crosslinking agent for epoxy resins or phenol-formaldehyde resins.

In addition, as meta-terphenyltetracarboxylic acid, a small amount of
The synthesis method is shown by the following reaction formula [].

That is, using copper as a catalyst, meta-benzenedisulfonyl chloride and excess phthalic anhydride are reacted under phthalic anhydride reflux conditions while generating sulfur dioxide gas and hydrogen chloride gas to form meta-terphenyltetracarboxylic acid. It is made into a dianhydride, and the melting point of the obtained compound is 130~
It was 165℃.

[Problem that the invention seeks to solve]

Polyimide resins obtained from conventionally known aromatic tetracarboxylic dianhydrides and diamine compounds, such as diaminodiphenyl ether and diaminodiphenylmethane, are known as heat-resistant resins, but recent technology With the advancement of technology, further improvement in heat resistance is desired.

Further, para-terphenyltetracarboxylic dianhydride represented by the above formula [] is known as a crosslinking agent for epoxy resins or phenolic resins.
However, since the para-terphenyltetracarboxylic dianhydride has acid anhydride groups at the 2,3-position and the 2'',3''-position, the polyimide resin synthesized using it as a raw material has a high It is difficult to quantify the molecular weight and therefore has insufficient heat resistance.

Furthermore, in the meta-terphenyltetracarboxylic dianhydride, the position of the acid anhydride group is unknown due to the nature of its synthesis reaction, and the melting point of the resulting compound is wide, ranging from 130 to 165°C. , is a mixture of various compounds with different positions of acid anhydride groups,
When such a tetracarboxylic dianhydride is used as a raw material for a polyimide resin, only a low molecular weight polyimide resin is obtained, and the heat resistance is insufficient.

In order to solve these problems, the present invention provides novel terphenyltetracarboxylic acids or dianhydrides thereof and methods for producing them.

[Means for solving problems]

The first invention is para-terphenyl-3,4,
It relates to 3″,4″-tetracarboxylic acid or its dianhydride.

Para-terphenyl-3,4,3'',4''-tetracarboxylic acid is a compound represented by the following formula [].

In addition, this dianhydride, para-terphenyl-3,4,3″,4″-tetracarboxylic acid-3,4,
3″,4″-dianhydride is a compound represented by the following formula [].

The novel para-terphenyltetracarboxylic acid or its dianhydride according to the present invention has carboxyl groups or acid anhydride groups at the 3,4-position and the 3'',4''-position, and at both ends of the para-terphenyl. It has a different structure from the conventional para-terphenyltetracarboxylic dianhydride represented by the formula []. Therefore, when polyamic acid is reacted with a diamine compound and further dehydrated to form a polyimide resin, it becomes a linear structure in which the molecules are extended, making it possible to provide a polyimide resin with excellent heat resistance.

The second invention relates to a method for producing the compound according to the first invention.

That is, the second invention is para-terphenyl-3,4,4, which is characterized by oxidizing 3,4,3'',4''-tetramethyl-para-terphenyl or further subjecting it to a dehydration ring-closure reaction. This invention relates to a method for producing 3″,4″-tetracarboxylic acid or its dianhydride.

The above 3,4,3'',4''-tetramethyl-para-terphenyl can be obtained by double cross-coupling reaction of a Grignard reagent of 4-halogeno-ortho-xylene and para-dihalogenobenzene.

The manufacturing method will be explained in detail below.

Para-terphenyltetracarboxylic acid and its dianhydride according to the present invention can be produced by the reaction represented by the following formula [].

(Here, X ₁ and X ₂ each independently represent chlorine, bromine, or iodine.) That is, 4-halogeno-ortho-xylene is reacted with metallic magnesium according to a conventional method to obtain a Grignard reagent, and then this Para-dihalogenobenzene and a nickel metal complex catalyst are added to the mixture to form tetramethyl-para-terphenyl through a double cross-coupling reaction. The resulting intermediate, 3,4,3'',4''-tetramethyl-para-terphenyl, was converted to para-terphenyl-3,4,3'' by permanganate, nitric acid, or liquid phase air oxidation.
4″-tetracarboxylic acid, and then heated or with acetic anhydride to obtain para-terphenyl-3,4,3″,
4″-Tetracarboxylic acid-3,4:3″,4″-dianhydride.Also, if 3,4,3″,4″-tetramethyl-para-terphenyl is oxidized in the gas phase, the above dianhydride can be directly obtained. Anhydrous products can be obtained.

This method will be explained in more detail.

As 4-halogeno-ortho-xylene, 4
-iodo-ortho-xylene, 4-bromo-ortho-xylene, etc.

The method of using 4-halogeno-ortho-xylene as a Grignard reagent is to use 1.0 gram atom or more of metallic magnesium per 1.0 mole of 4-halogeno-ortho-xylene. When the amount of magnesium metal is less than 1.0 gram atom, unreacted 4-halogeno-ortho-xylene remains and is combined with the Grignard reagent of 4-halogeno-ortho-xylene and 4-halogeno-ortho-xylene during the next coupling reaction.
This is not preferred because halogeno-ortho-xylene reacts to produce tetramethyl-biphenyl. The reaction temperature for Grignard reagent is 0℃
The above reaction is carried out at a temperature below the reflux temperature of the solvent, and the reaction time is 1 to 10 hours.

When the amount of metallic magnesium used in the reaction exceeds 1.0 gram atom per 1.0 mole of 4-halogeno-ortho-xylene, unreacted metallic magnesium remains, which is removed by filtration. Examples of solvents used at this time include methyl ether and tetrahydrofuran.

Examples of para-dihalogenobenzene include para-dibromobenzene and para-dichlorobenzene. Among these, when para-dichlorobenzene is used, the yield of the double cross-coupling reaction becomes higher.

The amount of para-dihalogenobenzene used is the Grignard reagent of 4-halogeno-ortho-xylene.
Use 0.5 mol per 1.0 mol. If the amount is less than 0.5 mol, Grignard reagent remains after the reaction is completed;
This is only hydrolyzed into ortho-xylene during the next water washing, and does not prevent the reaction, but the yield decreases. Moreover, if it exceeds 0.5 mol, the by-product of poly-para-phenylene increases, which is not preferable.

Examples of the nickel metal complex catalyst include dichlorobis(triphenylphosphine)nickel, dibromobis(triphenylphosphine)nickel, diiodobis(triphenylphosphine)nickel,
Dichloro[1,2-bis(diphenylphosphino)ethane]nickel, dibromo[1,2-bis(diphenylphosphino)ethane]nickel, dichloro[1,3-bis(diphenylphosphino)]
Propane]nickel, dibromo[1,3-bis(diphenylphosphino)propane]nickel, and the like.

The nickel metal complex catalyst is preferably used in an amount of 0.1 to 1.0% by weight based on the amount calculated as the 4-halogeno-ortho-xylene component of the Grignard reagent.

The double cross coupling reaction is preferably carried out at 20 to 60°C, and the reaction time is usually 1 to 5 hours. If the reaction temperature is low, the reaction time will only become longer and this is not an essential problem; however, if the reaction temperature is higher than 60°C, high boiling point components such as poly-para-phenylene or tetramethyl-biphenyl By-products tend to increase.

After the reaction is completed, the magnesium salt is removed by washing with water. Intermediate 3,4,3″,4″-tetramethyl-para-terphenyl is optionally mixed with toluene,
It can be purified by recrystallization using xylene or the like as a solvent.

Intermediate 3,4,3″,4″-tetramethyl-para-
Terphenyl can be oxidized to obtain para-terphenyl 3,4,3'',4''-tetracarboxylic acid according to the invention.

The case of oxidation using permanganate will be explained next.

As the permanganate, potassium permanganate or the like is used. The solvent used is a mixture of water and pyridine, preferably in a weight ratio of 0.5 to 2.0 pyridine to 1.0 water. This solution 100
5 to 15 g of 3,4,3'',4''-tetramethyl-para-terphenyl is added per g, and 12 times the mole of potassium permanganate is gradually added thereto. If the amount is less than 12 times the mole, the oxidation reaction will not be completed.

Reaction temperature is 50℃ or higher, reflux temperature (93℃)
The reaction time is usually 5 to 10 hours. In this reaction, potassium permanganate becomes manganese oxide, which is insoluble in the solvent, and this is removed by filtration. The filtrate contains para-terphenyl-3,4,
Since 3″,4″-tetracarboxylic acid is dissolved as a potassium salt, it is acid-precipitated using concentrated acid, but since the filtrate contains pyridine, the pyridine is distilled off using a rotary evaporator, and then the acid is removed. analyze.
Add concentrated hydrochloric acid until the pH of the solution reaches 1. White para-terphenyl 3,4,3″,4″-
Tetracarboxylic acid crystals are obtained. At this time, para-terphenyl-3,
4,3'',4''-tetracarboxylic acid is a compound having two molecules of water of crystallization.

The para-terphenyl thus obtained
3,4,3″,4″-tetracarboxylic acid, 120-250
℃ under reduced pressure of 5 to 50 mmHg for 1 to 24 hours, the above para-terphenyl-3,4,3'',
Para-terphenyl-3,4,3'',4 is obtained by adding 30 to 60 g of acetic anhydride to 1 g of 4''-tetracarboxylic acid, heating under reflux for 0.5 to 2 hours, followed by hot filtration and recrystallization. ″-tetracarboxylic acid-3,
4,3″,4″-dianhydride.

Para-terphenyl-3,4, according to the present invention
3″,4″-tetracarboxylic acid or its dianhydride is
It is useful as a raw material for polyimide resins and other resins, and as a curing agent for epoxy resins, phenolic resins, etc.

〔Example〕

Hereinafter, % means weight %.

Example 1 (1) Production of Grignard reagent A two-four-necked flask equipped with an Aline condenser, a dropping funnel, a thermometer, and a stirring device was thoroughly dried in an argon gas atmosphere, and then 100 ml of tetrahydrofuran, which had been dehydrated with metallic sodium, was added.
Magnesium metal 9.72g and bromo-ortho-
Xylene (4-bromo-ortho-xylene 75%
and 10.0 g of 25% mixture of 3-bromo-ortho-xylene) were added. The reaction solution started to become cloudy,
When the Grignard reagent began to form, a mixture of 64.0 g of the same bromo-ortho-xylene and 100 ml of tetrahydrofuran was added dropwise from the dropping funnel over 1 hour. During this time, since the reaction was exothermic, the reaction temperature was maintained at 40°C while cooling with an ice bath. Since metallic magnesium remained even after the dropwise addition was completed, the mixture was heated in an oil bath and stirred for 5 hours at a temperature of 40°C to completely react the metallic magnesium to form a Grignard reagent.

(2) Production of 3,4,3″,4″-tetramethyl-para-terphenyl Next, 0.37 g of dichloro[1,2-bis(diphenylphosphino)ethane]nickel catalyst (the above bromo-ortho -0.5% based on the total amount of xylene), and a solution of 29.4 g (0.200 mol) of para-dichlorobenzene dissolved in 85 ml of tetrahydrofuran was added from the dropping funnel to 1 ml of tetrahydrofuran.
It dripped over time. During this time, the reaction temperature was maintained at 35°C. After the dropwise addition was completed, stirring was continued for another hour while maintaining the temperature at 35°C to complete the double cross coupling reaction.

To the reaction completed solution, 300 ml of toluene was added, and while stirring, 150 ml of ion-exchanged water was gradually added over 1 hour. After removing the lower aqueous layer using a separatory funnel, the upper toluene layer was heated, filtered while hot, and the filtrate was allowed to cool to precipitate colorless flaky crystals. Crystals were collected by filtration and dried to yield 26.8 g.

The melting point of this crystal is 168-169°C, and Figure 1 shows the proton nuclear magnetic resonance ( ^1H -NMR) spectrum and Figure 2 shows the carbon nuclear magnetic resonance ( ^13C -NMR) spectrum.
NMR) spectrum analysis results are shown. In Figure 1, the integrated intensity ratio of absorption based on methyl group protons at 2.29 ppm and 2.32 ppm and absorption based on benzene ring protons at 7.17 to 7.65 ppm is 180:150 (=12:10). , which is in good agreement with the theoretical value. In Figure 2, only 10 peaks appear, indicating that the obtained compound (theoretical carbon 22) has a symmetrical structure. Moreover, the expression [] Absorptions 1 to 8 appear in FIG. 2 in good agreement with the expected value of the chemical shift of the benzene ring carbon according to Savitzky's rule for the benzene ring carbon with carbon number ~ of the compound represented by .

From the above, it was confirmed that the above crystal was 3,4,3'',4''-tetramethyl-para-terphenyl.

(3) Production of para-terphenyl-3,4,3″,4″-tetracarboxylic acid Next, 14.3 g (50 mmol) of 3,4,3″,4″-tetramethyl-para-terphenyl, 200 g of pyridine, and Pour 200 g of ion-exchanged water into a 14-necked flask equipped with an Allene condenser, thermometer, and stirrer, heat the inside of the flask to 80°C, and gradually add 110.7 g (700 mmol) of potassium permanganate over 3 hours. After that, the temperature was maintained at 80° C. and stirring was continued for an additional 5 hours. The precipitate of manganese oxide produced in the reaction was removed by filtration, and the pyridine in the filtrate was distilled off using a rotary evaporator. After acid precipitation with 36% hydrochloric acid, fine white crystals were precipitated. The pH of the solution at this time was 1. After repeating filtration and washing with water twice, it was dried under reduced pressure to obtain 11.6 g of white powdery crystals.

The melting point of this crystal was 311-313°C. The infrared absorption spectrum of this crystal is shown in FIG. For 0.4g of this crystal, 50ml of methanol and 97%
2 ml of sulfuric acid was added and refluxed for 8 hours to methyl esterify the above crystals. The results of the ¹ H-NMR spectrum of the obtained methyl ester compound are shown in FIG. In Figure 4,
The integrated intensity ratio of the absorption based on methyl group protons at 3.91ppm and 3.94ppm and the absorption based on benzene ring protons at 7.71 to 7.95ppm is as follows:
The value was 180:151 (=12:10.07), which was in good agreement with the theoretical value (methyl ester of the compound of formula []).

Further, the results of elemental analysis of the above crystal were as follows.

Actual value Carbon: 59.67%, Hydrogen 4.15% Theoretical value Carbon: 65.03%, Hydrogen 3.47% (However, the theoretical value is the value obtained as a compound of formula []) As the result of elemental analysis, the actual value and the theoretical value are different. When the above results were analyzed using a differential thermal balance at a heating rate of 5°C/min, endothermic peaks were found at 160°C, 230°C, and 310°C.
A total weight loss of 17% by weight was observed at °C.
The endothermic peak at 310°C is due to the melting point, but the endothermic peaks at 160°C and 230°C are due to dehydration. para-terphenyl-3,
If 4,3″,4″-tetracarboxylic acid simply undergoes dehydration and ring closure due to heating during differential calorimetry analysis and becomes the corresponding acid anhydride, the weight loss would be 9%.
It is. Therefore, the obtained crystals are considered to have water of crystallization, and the actual values of the above elemental analysis are as follows:
The theoretical value of elemental analysis when two molecules of crystal water are hydrated in the compound of formula []: carbon 59.73%, hydrogen 4.10
% agrees very well.

From the above, it was confirmed that the above crystal was para-terphenyl-3,4,3'',4''-tetracarboxylic acid represented by the formula [] and had two molecules of water of crystallization.

(4) Production of para-terphenyl-3,4,3″,4″-tetracarboxylic acid-3,4,3″,4″-dianhydride Next, 10.0 g of the above crystals and 400 g of acetic anhydride were combined into one composition. The mixture was placed in a plastic flask, heated under reflux for 30 minutes to dissolve, filtered hot, and allowed to cool. When this was done, light colored powdery fine crystals were precipitated. It was filtered and dried under reduced pressure to obtain 6.9 g of powdered crystals. This powder crystal infrared spectrum and ¹ H−
The NMR spectra are shown in FIGS. 5 and 6, respectively.

The melting point of this crystal is 311 to 313°C, and elemental analysis shows that it is 71.28% carbon and 2.76% hydrogen, which is in good agreement with the theoretical value (compound of formula []) of 71.36% carbon and 2.72% hydrogen, and is para- terphenyl
3,4,3″,4″-tetracarboxylic acid-3,4:
It was confirmed that it was a 3″,4″-dianhydride.

Application example Para-terphenyl-3 obtained in Example 1,
4,3″,4″-tetracarboxylic acid-3,4,3″,
10.0 g (27.0 mmol) of 4″-dianhydride, 5.41 g (27.0 mmol) of 4,4′-diaminodiphenyl ether and N-methylpyrrolidone as reaction solvent.
87.3g was placed in a 200ml three-necked flask equipped with a stirring device, and stirred for 8 hours at a temperature of 25°C under a nitrogen atmosphere.
weight%). During the reaction, the maximum viscosity of the polyamic acid varnish was 30 poise (measured at 25°C).

The obtained polyamic acid varnish was cast onto a glass plate and heated at 150℃ for 1 hour and 350℃ in a hot air constant temperature bath.
C. for 1 hour to remove the reaction solvent and convert the polyamic acid into polyimide through a dehydration reaction to obtain a polyimide film with a thickness of 40 .mu.m.

After this polyimide film was left in the air at 460°C for 30 minutes, the weight loss was 2.1% by weight, and the temperature at which weight loss started was 472°C as determined by thermobalance analysis (heating rate: 10°C/min).

Comparative application example Pyromellitic dianhydride 8.0 g (36.7 mmol), 4,4'-diaminodiphenyl ether 7.34
g (36.7 mmol) and N-methylpyrrolidone
86.9g was reacted in the same manner as in the application example to synthesize a polyamic acid varnish with a nonvolatile content of 15% by weight. At this time,
The maximum viscosity of polyamic acid varnish during the reaction is 3000
It was poise (measured at 25℃).

A polyimide film was obtained from the obtained polyamic acid varnish in the same manner as in the application example, and the heat resistance of this film was measured.The weight loss after being left in the air at 460°C for 30 minutes was 3.5% by weight, which was determined by thermobalance analysis. (Temperature increase rate 10℃/min) The starting temperature for weight loss is 460℃
It was hot.

〔Effect of the invention〕

Para-terphenyl-3,4, according to the present invention
3″,4″-tetracarboxylic acid or its dianhydride is
It is a new compound and is useful as a raw material for polyimide resins, etc.

[Brief explanation of the drawing]

Figure 1 shows intermediates 3 and 3 in Example 1.
¹ H-NMR spectrum of 4,3″,4″-tetramethyl-para-terphenyl, Figure 2 shows 3,4,
3″,4″-tetramethyl-para-terphenyl
¹³ C-NMR spectrum, Figure 3 is the infrared absorption spectrum of para-terphenyl-3,4,3'',4''-tetracarboxylic acid, Figure 4 is the para-terphenyl-3,4,3'',4''- ¹ H-NMR spectrum of tetracarboxylic acid tetramethyl ester, Figure 5 shows the infrared spectrum of para-terphenyl-3,4,3'',4''-tetracarboxylic acid-3,4:3'',4''-dianhydride. The absorption spectrum and Figure 6 show para-terphenyl-3,4,3″,4″-tetracarboxylic acid-3,
4: ¹ H-NMR spectrum of 3″,4″-dianhydride is shown.

Claims (1)

[Claims] 1. Para-terphenyl-3,4,3'',4''-tetracarboxylic acid or its dianhydride. 2 Para-terphenyl-3,4,3″,4″-tetra characterized by oxidizing 3,4,3″,4″-tetramethyl-p-terphenyl or further subjecting it to a dehydration ring closure reaction thereafter. A method for producing carboxylic acid or its dianhydride. 3 3,4,3″,4″-tetramethyl-para-terphenyl is obtained by double cross-coupling reaction of a Grignard reagent of 4-halogeno-ortho-xylene and para-dihalogenobenzene. A method for producing para-terphenyl-3,4,3'',4''-tetracarboxylic acid or its dianhydride according to Scope 2. 4. The method for producing para-terphenyl-3,4,3'',4''-tetracarboxylic acid or its dianhydride according to claim 3, wherein the para-dihalogenobenzene is para-dichlorobenzene.