JPH038654B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an improved method for producing polycyanoaryl ethers. More specifically, the present invention uses dihalogenobenzonitrile and resorcinol as the main raw materials, and uses polycyanosine that has excellent heat resistance, particularly a high thermal decomposition initiation temperature, and is suitable as a material for electrical and electronic equipment and mechanical parts. The present invention relates to a method for effectively producing aryl ethers.

[Conventional technology]

Traditionally, as a polymer with excellent mechanical and thermal properties, the formula Polyaryletherketones shown by are known.

However, this polyaryletherketone can be produced by polymerizing 4-phenoxybenzoyl chloride in a hydrofluoric acid solvent in the presence of a boron trifluoride catalyst. In addition to being difficult, there was the problem that hydrofluoric acid had to be used, which was expensive, harmful, and extremely difficult to handle.

Therefore, there is a need to develop other methods to produce polyaryletherketones without using hydrofluoric acid or to develop other polymers with properties comparable to those of this polyaryletherketone, such as polycyanoarylethers. Development is being attempted.

Polycyanoaryl ethers with various structures have been developed so far. For example, in a dipolar neutral solvent, dinitrobenzonitrile and an alkali metal salt of a dihydroxy aromatic compound, or these and a dihalogeno aromatic A dihydroxy aromatic compound having two hydroxyl groups at the p-position and two halogen atoms or nitro groups in a specific solvent (Japanese Unexamined Patent Publication No. 14270/1983) A product obtained by reacting benzonitrile having

Polycyanoaryl ethers are attracting attention because they can be easily produced and have good mechanical and thermal properties.

However, a polymer obtained from dihalogenobenzonitrile and resorcinol has not been known so far.

Therefore, the present inventors conducted repeated research and succeeded in producing polycyanoaryl ether from dihalogenobenzonitrile and resorcinol. Since the crystallization rate is extremely fast and the low polymer precipitates from the reaction system during the polymerization reaction, the heat resistance is not necessarily satisfactory.

[Problem that the invention seeks to solve]

Under these circumstances, an object of the present invention is to provide a polycyanoaryl ether having excellent heat resistance, particularly a high thermal decomposition initiation temperature, made from dihalogenobenzonitrile and resorcinol.

[Means for solving problems]

The present inventors have conducted intensive research to develop polycyanoaryl ether having excellent heat resistance, and as a result, in a specific solvent, in the presence of a lithium compound, dihalogenobenzonitrile and resorcinol The inventors have discovered that the object can be achieved by reacting the lithium salt with an alkali metal salt other than the lithium salt, and have completed the present invention based on this knowledge.

That is, in producing polycyanoaryl ether by reacting dihalogenobenzonitrile with an alkali metal salt of resorcinol in a neutral polar solvent, the present invention provides a method for producing a polycyanoaryl ether by reacting a dihalogenobenzonitrile with an alkali metal salt of resorcinol. The present invention provides a method for producing polycyanoaryl ether, which is characterized by using at least one alkali metal salt selected from rubidium salts and cesium salts, and carrying out the reaction in the presence of a lithium compound.

In the method of the present invention, dihalogenobenzonitrile used as one of the raw materials has the general formula (In the formula, X ₁ and X ₂ are each a halogen atom, and they may be the same or different.) In which X ₁ and X ₂ are chlorine atoms. and fluorine atoms are preferred.

Specific examples of this dihalogenobenzonitrile include 2,6-dichlorobenzonitrile, 2,4-
Dichlorobenzonitrile, 2,6-difluorobenzonitrile, 2,4-difluorobenzonitrile, 2-chloro-6-fluorobenzonitrile,
2-chloro-4-fluorobenzonitrile, 2-
Preferred examples include fluoro-4-chlorobenzonitrile, and 2,6-dichlorobenzonitrile is particularly preferred.

Examples of the neutral polar solvent used in the present invention include N-methylpyrrolidone, N-ethylpyrrolidone, dimethylformamide, diethylformamide, dimethylacetamide, diethylacetamide, dimethylimidazolidinone, dimethylsulfoxide, and hexamethylformamide. It will be done. If desired, other solvents such as aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, chlorobenzene, and dichlorobenzene can be added to these neutral polar solvents.

The method of the present invention is a method in which the dihalogenobenzonitrile and the alkali metal salt of resorcinol are reacted in the presence of a lithium compound in the neutral polar solvent.

The alkali metal salt of resorcinol chemically reacts with at least one alkali metal compound such as an alkali metal other than lithium, such as a hydroxide, carbonate, or hydrogen carbonate such as sodium, potassium, rubidium, or cesium, in a solvent. It can be produced by reacting in stoichiometric proportions. Among the alkali metal compounds mentioned above, sodium and potassium hydroxides, carbonates, and hydrogen carbonates are preferred.

The alkali metal salt of resorcinol thus obtained may be isolated and used as a raw material for the polymerization reaction, or the metal salt can be obtained by using the neutral polar solvent used in the polymerization reaction as a solvent and then It may be used as is in the polymerization reaction without being separated.

Furthermore, when dihalogenobenzonitrile and resorcinol are reacted, they may be converted into an alkali metal salt of resorcinol and then reacted.

Examples of lithium compounds include lithium carbonate, lithium acetate, lithium borate, lithium sulfide, lithium fluoride, lithium oxalate, and lithium formate.

In the present invention, it is desirable to use the raw material dihalogenobenzonitrile and the alkali metal salt of resorcinol in a substantially equimolar ratio.

There are no particular restrictions on the amount of solvent used, but it is usually 0.5 to 50 times, preferably 2 to 20 times the total amount of dihalogenobenzonitrile, resorcinol alkali metal salt, and lithium compound on a weight basis. Used in a double range. The amount of the lithium compound added is preferably in the range of 0.5 to 10 g per 1 dl of the solvent used.

Reaction temperature is 150-350℃, preferably 180-320℃
The reaction time depends on the type and concentration of the raw materials used, the type of alkali metal salt of resorcinol, the type and amount of lithium compound added, the reaction temperature, etc., but is generally about 0.5 to 10 hours. It is.

The reaction is preferably carried out under an inert gas atmosphere such as nitrogen or argon, and the reaction pressure is not particularly limited and may be at reduced pressure, atmospheric pressure, or increased pressure, but the reaction is usually carried out under atmospheric pressure. It will be done.

When dihalogenobenzonitrile and resorcinol are reacted, water is generated during the reaction in the method of converting resorcinol to an alkali metal salt, but in order for the reaction to proceed smoothly, this generated water is removed from the system. This is desirable. As a removal method, for example, a substance that can form an azeotrope with water, such as aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, chlorobenzene, and dichlorobenzene, is added to a neutral polar solvent and a reaction is carried out. , a method in which the produced water is removed as an azeotrope is preferably used.

The produced polymer can be recovered by commonly used methods such as coagulation, solidification, granulation, extraction, and solvent distillation.

The polymer thus obtained has the formula The reduced viscosity [ηsp/c] of a 0.2 g/dl solution using p-chlorophenol as a solvent at a temperature of 60°C is 0.5 dl/dl.
g or higher, and has high heat resistance, particularly a high thermal decomposition initiation temperature.

〔Example〕

EXAMPLES Next, the present invention will be explained in more detail with reference to examples, but the present invention is not limited to these examples in any way.

Example 1 In a 300 ml separable flask equipped with a rectification device, a stirring device, and an argon gas blowing tube,
- Add 12.161 g (0.071 mol) of dichlorobenzonitrile, 7.707 g (0.070 mol) of resorcinol, 10.158 g (0.074 mol) of potassium carbonate, 1.5 g of lithium carbonate as a lithium compound, 100 ml of N-methylpyrrolidone and 50 ml of toluene as a solvent, and put into a flask. After replacing the inside with argon, the temperature reached 198℃ in 1 hour.
The temperature was raised to 198° C. and maintained at 198° C. for 4 hours with stirring, and the reaction was carried out while water produced by the reaction was removed from the system by azeotropy with toluene. After the reaction was completed, the product was cooled to room temperature, poured into methanol, and pulverized using a Warning blender.
1 dose of water containing 1 g of oxalic acid, 2 doses of 1 dose of water
After washing once with methanol and once with methanol, it was dried.

As a result, the expression 13.4g of polymer consisting of repeating units shown by
(yield 95%) was obtained.

This polymer has a reduced viscosity [ηsp/c] measured at 60°C (measured in the same manner in the following examples) in a solution with a concentration of 0.2 g using p-chlorophenol as a solvent.
It was 0.71 dl/g. Next, the proportion of oligomers with a molecular weight of 5,000 or less contained in this polymer is
As a result of measurement by gel permeation chromatography, it was 2.1% by weight.

Furthermore, as a result of measuring the thermal properties of this polymer, the glass transition temperature (Tg) was 143℃, the melting point (Tm) was 340℃, and the thermal decomposition onset temperature (Td) was 510℃.
It was hot (in the air).

Example 2 The amount of lithium carbonate added in Example 1 was changed to 2.5
13.4 g (yield: 95%) of the polymer was obtained by carrying out the same operation as in Example 1, except that the polymer was changed to 13.4 g (yield: 95%). The reduced viscosity [ηsp/c] of the obtained polymer was 0.68 dl/g, and the content of oligomers having a molecular weight of 5,000 or less was 3.2% by weight. Furthermore, regarding the thermal properties of this polymer, Tg is 143℃, Tm is 340℃,
Td was 515°C (in air).

Example 3 Example 1 except that 3.4 g of lithium acetate dihydrate was used as the lithium compound.
Using exactly the same procedure as above, 13.5 g of polymer (yield 96
%) was obtained.

The reduced viscosity [ηsp/c] of the obtained polymer was 0.76
dl/g, and the content of oligomers with a molecular weight of 5,000 or less was 2.5% by weight. Furthermore, regarding the thermal properties of this polymer, Tg is 143℃, Tm
was 340°C, and Td was 510°C (in air).

Comparative Example 13.2 g (yield: 93.5%) of a polymer was obtained by carrying out exactly the same operation as in Example 1, except that no lithium compound was added. The reduced viscosity [ηsp/c] of the obtained polymer was 0.59 dl/g
It was hot. Further, the content of oligomers having a molecular weight of 5,000 or less was 10.8% by weight. moreover,
Regarding thermal properties, Tg is 143℃, Tm is 340℃,
Td was 460°C (in air).

〔Effect of the invention〕

According to the method of the present invention, a polycyanoaryl ether having excellent heat resistance, particularly a high thermal decomposition initiation temperature, can be easily produced from 2,3-dihalogenobenzonitrile and resorcinol.

This polycyanoaryl ether is suitably used as a material for, for example, electrical and electronic equipment and mechanical parts.

Claims (1)

[Claims] 1. In producing polycyanoaryl ether by reacting dihalogenobenzonitrile with an alkali metal salt of resorcinol in a neutral polar solvent, sodium salt, potassium salt, rubidium salt, and cesium are used as the alkali metal salt of resorcinol. A method for producing polycyanoaryl ether, which comprises using at least one alkali metal salt selected from salts and carrying out the reaction in the presence of a lithium compound.