JPS6362535B2 - - Google Patents

Description

[Detailed description of the invention]

[Technical Field of the Invention] The present invention relates to a method for producing polycyanoaryl ether, and more particularly, to a method for producing polycyanoaryl ether, which allows the polymer to have a high molecular weight easily and has excellent productivity. [Technical background of the invention and its problems] Various polycyanoaryl ethers
- Disclosed in Publication No. 14270. The polycyanoaryl ether disclosed in this publication is produced by reacting dinitrobenzonitrile and dihydric phenol as raw materials, but a polymer having a sufficiently high molecular weight cannot be obtained by this method. Therefore, the present inventors proposed a method for obtaining high molecular weight polycyanoaryl ether using dihalogenobenzonitrile and an alkali metal salt of dihydroxynaphthalene as raw materials (Japanese Patent Application No. 1403-1983). The polymer obtained by this method is
Although its molecular weight is higher than that of the polymer obtained by the former method, it cannot be said that the molecular weight has been sufficiently increased and improvement is desired. [Object of the Invention] The object of the present invention is to provide a method for producing polycyanoaryl ether having a sufficiently high molecular weight easily and with high productivity. [Summary of the Invention] In order to achieve the above-mentioned object, the present inventors have investigated various ways to further increase the molecular weight in the above-mentioned method, and as a result, the present inventors have conventionally conducted a method to increase the molecular weight of polycyanoarylether. At the time, the amount of raw materials charged was set low because an increase in the amount of raw materials charged made it difficult to control the reaction. By increasing the molecular weight, it is possible to increase the molecular weight even higher than before, and the reaction time required for this is shorter than before, improving productivity during polymer production. The present invention was completed by discovering the fact that the physical properties are superior to those of the conventional case. That is, the method for producing polycyanoaryl ether of the present invention includes dihalogenobenzonitrile,
A method for producing polycyanoaryl ether, which comprises reacting 2,7-dihydroxynaphthalene with an alkali metal salt in the presence of a neutral polar solvent, and then treating the resulting reaction product with water or alcohol. benzonitrile and the 2,7
- an alkali metal salt of dihydroxynaphthalene in a supply ratio of 0.07 to 0.2 mol per 1 dl of the neutral polar solvent. In the method of the present invention, two types of compounds explained below are used as starting materials. The first starting material has the following formula: (In the formula, X represents a halogen atom.) It is a dihalogenobenzonitrile represented by the following formula. In the compound of formula (), Cl and F are preferable as halogen X. Specific examples of the compound of formula () include 2,4-dichlorobenzonitrile, 2,6
-dichlorobenzonitrile, 2,4-difluorobenzonitrile, and 2,6-difluorobenzonitrile are preferred. The second starting material has the following formula: (In the formula, M represents an alkali metal.) This is an alkali metal salt of 2,7-dihydroxynaphthalene. In the compound of formula (), M may be any alkali metal, but especially
Na and K are preferred. The compound of formula () can be prepared by neutralization reaction of 2,7-dihydroxynaphthalene with an alkali metal salt such as potassium carbonate or potassium hydroxide. In addition, when proceeding with the polymerization reaction described below, for example, 2,7-dihydroxynaphthalene and the above-mentioned alkali metal salt are added together to the reaction system without using the compound of formula () from the beginning. You can leave it as is. In this case, as the reaction progresses, a compound of formula () will be produced within the reaction system. Regarding the supply ratio of the starting materials, dihalogenobenzonitrile and alkali metal salt of 2,7-dihydroxynaphthalene are each supplied in an amount of 0.07 to 0.2 mol per 1 dl of the neutral polar solvent described below. This supply ratio constitutes the greatest feature of the present invention. If the supply ratio of each is outside the above range
If the amount is less than 0.07 mol, the molecular weight will increase, but the reaction time required will be too long, making it unsuitable for industrial use.If it exceeds 0.2 mol, the viscosity of the reaction product will become too large, making stirring and temperature difficult. Reaction control such as control becomes difficult, and a predetermined polymerization reaction cannot proceed smoothly. Preferably, it is 0.1 to 0.15 mol. On the other hand, regarding the supply ratio between dihalogenobenzonitrile and the alkali metal salt of 2,7-dihydroxynaphthalene, the two may be supplied in approximately equimolar amounts, or the dihalogenobenzonitrile may be supplied in a slightly larger amount than the alkali metal salt of 2,7-dihydroxynaphthalene. It is better to supply more. In addition, when the reaction is carried out by supplying 2,7-dihydroxynaphthalene and an alkali metal salt together to the reaction system, the amount of 2,7-dihydroxynaphthalene is approximately equivalent to that of dihalogenobenzonitrile, or slightly more than that. It is preferable to supply the alkali metal salt in a small amount, and supply the alkali metal salt in an amount equal to or more than the 2,7-dihydroxynaphthalene mole. Examples of the neutral polar solvent used in the present invention include dimethylacetamide, dimethylsulfoxide, N-methylpyrrolidone, sulfolane, dimethylformamide, diethylsulfoxide, and dimethylsulfolane. During the polymerization reaction, together with these neutral polar solvents, an azeotropic solvent with water,
For example, toluene, benzene, xylene, ethylbenzene, and chlorobenzene may be used. The amount of the azeotropic solvent used with water may be sufficient to azeotropically remove the water produced in the reaction between 2,7-dihydroxynaphthalene and the alkali metal salt. Polymerization reaction temperature is 160~350℃, preferably 190~
250℃, polymerization reaction time is 1 to 3 hours, preferably
It is 1.5-2.5 hours. Further, the reaction may be carried out under normal pressure or slightly increased pressure. At the end of the polymerization reaction under the above conditions, the polymer concentration will be 20 to 50 g/dl (however, the polymer concentration represents the weight of the produced polymer per 1 dl of neutral polar solvent), and high molecular weight can be achieved. . In addition, in this process, as a molecular weight regulator, the following formula: (In the formula, R represents any one of a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an aryl group, an aralkyl group, and a cyano group.) It is preferable to add a monovalent phenol represented by the following formula. Examples of monovalent phenols represented by formula () include:

【formula】

【formula】

[Formula] can be given. Further, the amount of the molecular weight regulator to be added is determined based on the relationship with the molecular weight of the target polymer. Next, the reaction product obtained through the above process is treated with water or alcohol to eliminate the alkali metal present at the end of the reaction product and replace it with H and OH. As the alcohol, methanol and ethanol are preferred. Further, as a treatment method, it is sufficient to simply throw the above reaction product into water or alcohol. The polymer obtained by the above method has the following formula: The repeating unit shown by is the basic skeleton. According to the method of the present invention, the obtained polymer is p-
Dissolve in chlorophenol to a concentration of 0.2g/
dl, a polymer with a high molecular weight such that the reduced viscosity [η sp/c] of this resin solution at 60°C is 1.0 dl/g or more can be obtained, and the time required for the reaction is shorter than that of the conventional production method. It is shortened compared to the case of [Embodiments of the Invention] Example 1 A separable flask with an internal volume of 300 ml equipped with a stirring device, a rectification device, and an argon gas blowing tube,
17.2 g (0.1 mol) of 2,6-dichlorobenzonitrile and 16.02 g of 2,7-dihydroxynaphthalene
(0.1 mol), potassium carbonate 16.585g (0.12 mol),
100 ml of sulfolane degassed with argon and 50 ml of toluene as an azeotropic solvent with water were charged, and the mixture was reacted at 160° C. for 2 hours while blowing argon gas, and the water produced was distilled off together with the toluene. Next, the temperature was raised to 200°C and the mixture was reacted for 2 hours. After the reaction was completed, the product was cooled to room temperature and poured into methanol to precipitate and collect the polymer. Next, this polymer was pulverized using a blender manufactured by Warning Co., Ltd.
The mixture was washed with two portions of hot water and two portions of methanol, and dried under reduced pressure at 120° C. for 8 hours to obtain 25.92 g of a polymer. Polymer concentration at the end of the polymerization reaction and 0.2 g of the obtained polymer using p-chlorophenol as a solvent
Reduced viscosity at 60℃ of a solution with dl concentration [η sp/
c] was measured and the results are shown in the table. In addition, in order to investigate the thermal properties of the polymer, the glass transition temperature, melting point, and thermal decomposition onset temperature were measured, and the results are shown in the table. Next, a press film was produced using this polymer, and the following mechanical properties were measured using this film, and the results are shown in the table. That is,
Yield strength, breaking strength, tensile modulus, and elongation are
The bending strength and flexural modulus were measured in accordance with ASTM D 638, and the bending strength and flexural modulus were measured in accordance with ASTM D 790. Example 2 The amount of 2,7-dihydroxynaphthalene used
Example 1 except that it was 15.859 g (0.099 mol)
Produce polycyanoaryl ether in the same way as
Similarly, each characteristic was measured. Example 3 2,6-dichlorobenzonitrile 24.08g
(0.14 mol), 2,7-dihydroxynaphthalene
22.2g (0.1386mol), potassium carbonate 23.2g
(0.168 mol), 100 ml of sulfolane, 70 ml of toluene, and the reaction temperature in the latter stage was 230°C.
Polycyanoaryl ether was produced in the same manner as in Example 1, and its properties were measured in the same manner. Comparative example 1 2,6-dichlorobenzonitrile 6.888g
(0.04 mol), 2,7-dihydroxynaphthalene
6.343g (0.0396mol), potassium carbonate 6.634g
Polycyanoaryl ether was produced in the same manner as in Example 1, except that (0.048 mol), 100 ml of sulfolane, and 50 ml of toluene were used, and each property was measured in the same manner. Comparative example 2 2,6-dichlorobenzonitrile 6.88g (0.04
mole), 2,7-dihydroxynaphthalene 6.343g
(0.0396 mol), potassium carbonate 6.634 g (0.048 mol), sulfolane 100 ml, toluene 50 ml, and the polymerization reaction time was 3 hours. Polycyanoaryl ether was produced in the same manner as in Example 1. Characteristics were measured. The above results are shown in the table.

【table】

[Table] [Effects of the Invention] As is clear from the examples of the invention, the method of the present invention is a method for easily producing polycyanoaryl ether having a higher molecular weight than conventional methods with high productivity. Furthermore, the polycyanoaryl ether obtained by the method of the present invention has excellent mechanical properties. Therefore, the method of the present invention contributes to increasing the molecular weight of polycyanoaryl ether, which is useful as a material for parts of electronic/electrical devices and machines, and to increasing its productivity, and has great industrial value.

Claims (1)

[Claims] 1. Dihalogenobenzonitrile and an alkali metal salt of 2,7-dihydroxynaphthalene are reacted in the presence of a neutral polar solvent, and then the resulting reaction product is treated with water or alcohol. A method for producing a polycyanoaryl ether, characterized in that the dihalogenobenzonitrile and the alkali metal salt of 2,7-dihydroxynaphthalene are each supplied at a rate of 0.07 to 0.2 mol per 1 dl of the neutral polar solvent. A method for producing polycyanoaryl ether.