JPS61246233A - Production of polycyanoaryl ether powder - Google Patents

Abstract

PURPOSE:To obtain the titled fine powder of excellent heat resistance and a high purity without grinding, by forming a polymer by reaction in the presence of a polymerization solvent, diluting the formed solution with said solvent to a specified polymer concentration and cooling this solution. CONSTITUTION:A polymer is formed by reacting approximately equimolar amounts of a dihalogenobenzonitrile (A) and a mixture (B) of 100-80mol% alkali metal diphenolate of formula I (wherein Ar is any one of the groups of formulas II-V and M is an alkali metal) and 0-20mol% alkali metal diphenolate of formula VI (wherein Ar' is a bivalent aryl other than Ar) at 180-240 deg.C and a pressure of normal pressure to slightly elevated pressure for 1-3hr in a polymerization solvent (C) such as sulfolane. The concentration of the obtained polymer solution is adjusted to a polymer concentration of 2-16g/dl by adding solvent C. The resulting polymer solution is cooled to 10-60 deg.C to precipitate the polymer as extremely fine powder and purify it efficiently. Thus, the titled powder is obtained.

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to a method for producing polycyanoarylether powder, and more specifically, the present invention relates to a method for producing polycyanoarylether powder, and more specifically, a method for producing polycyanoaryl ether powder, which can be sufficiently purified without the need for a step of pulverizing the obtained polymer. The present invention relates to a method for obtaining fine polymer powder.

[Technical background of the invention and its problems] Polycyanoaryl ether is known as a material for electrical/electronic equipment and mechanical parts.

This polycyanoaryl ether is manufactured in the following manner. For example, in JP-A-47-14270, polycyanoaryl ether is manufactured by reacting dinitrobenzonitrile with dihydric phenols. A method is disclosed. However, in this method, the polycyanoaryl ether cannot be made to have a sufficiently high molecular weight, so the heat resistance of the obtained polycyanoaryl ether cannot be said to be sufficient.

Therefore, as a result of repeated research to develop polycyanoaryl ether with excellent heat resistance, the present inventors found that through the reaction of dihalogenobenzonitrile and dihydric phenols,
discovered and proposed a method to obtain a polymer with high molecular weight, that is, a polymer with excellent heat resistance (Japanese Patent Application No. 13137-1982,
Publication No. 59-185855).

However, the polymers obtained by these methods are bulky and relatively coarse, and therefore, during purification, it is necessary to mechanically crush the polymers to further refine them. This poses a problem in that the pulverization process consumes a large amount of energy, complicates the entire process, and the resulting powder has a relatively large particle size, making it impossible to obtain a sufficient purification effect.

[Object of the invention] The present invention has the following features:1. The object of the present invention is to solve the above problems and provide a method for producing sufficiently purified fine polycyanoaryl ether powder without requiring a step of pulverizing the obtained polymer.

[Summary of the invention] The method for producing polycyanoaryl ether powder of the present invention includes:
With dihalogenobenzonitrile.

The following formula: MO-Ar-0N =...
・= (I); In addition, the polymer concentration was increased from 2 to 18 g/
It is characterized in that it is cooled to 10 to 80°C after being brought to dl.

In the present invention, dihalogenobenzonitrile used as a starting material includes 2,4-dichlorobenzonitrile and 2,6-dichlorobenzonitrile.

2.4-difluorobenzonitrile, 2.4-difluorobenzonitrile, 2. B-difluorobenzonitrile is preferred.

One starting material is an alkali metal salt of dihydric phenol represented by formula (1). In the compound of formula (■), any alkali metal may be used, but Na is particularly preferred.

In addition, when polycyanoaryl ether is used as a copolymer, together with the compound of formula (I), the following formula: MO
-At'-ON ・・・・・・・・・(n)
It is preferable to use an alkali metal salt of a dihydric phenol represented by the formula (■) as a copolymerization component. It is necessary to mix the compound so that it is less than 20 mol%. When the amount of the compound of formula (■) used is 20 mol % or more, the crystallinity of the obtained polycyanoaryl ether copolymer is low and powdering does not occur.

The powder manufacturing method of the present invention comprises a first step of reacting the dihalogenobenzonitrile and an alkali metal salt of dihydric phenol in the presence of a polymerization solvent to obtain a polymer, and a reaction system after the completion of the polymerization reaction. The second step is to add the polymerization solvent to a solution having the polymer concentration described below, and then cool this solution to precipitate a fine powder. This is the greatest feature of the invention.

First, the first step is a step of polymerizing dihalogenobenzonitrile and an alkali metal salt of dihydric phenol in the presence of a polymerization solvent.

Examples of the polymerization solvent used at this time include sulfolane, dimethyl sulfoxide, diethyl sulfoxide, dipropylsulfoxide, and dibutyl sulfoxide.
Among these, sulfolane is preferred.

In addition, in this step, from the beginning of the reaction, formula (I), (■
Instead of directly using the compound of formula As a result, compounds of formula (I) and formula (■) are produced in the reaction system.

The amount of the starting material to be used is determined based on the relationship with the degree of polymerization of the desired polymer, but it is preferable to use approximately equimolar amounts of dihalogenobenzonitrile and the alkali metal salt of dihydric phenol.

Regarding the amount of each used, in order to satisfy the range of polymer concentration described below, the amount of dihalogenobenzonitrile and alkali metal salt of dihydric phenol used per 1 d411 of the polymerization solvent should be adjusted from the beginning. Although it is possible to set the concentration lower, however, if the polymerization reaction is carried out by setting the raw material concentration to such a low level from the beginning, it will be disadvantageous in terms of productivity.

In other words, since the amount of polymerization solvent used is large compared to the amount of starting materials used, the time required for the polymerization reaction becomes longer.
In addition, a large-volume reaction vessel must be used, and in addition, a large amount of energy is consumed for heating, leading to a decrease in productivity.

The polymerization reaction conditions are 180 to 240°C, preferably 180 to 220°C, and a reaction time of 1 to 3 hours, preferably 1.5 to 2.5 hours. Do it under pressure.

In addition, if the chemical compound of formula (I) or formula (■) is not used from the beginning, one reaction source degree of 140 to 180
C., preferably 150 DEG to 180 DEG C., and a reaction time of 1 to 3 hours, preferably 1.5 to 2.0 hours, to carry out the reaction to produce the compounds of formulas (I) and (■).

The second step is a step in which the polymer solution obtained after one polymerization reaction is completed is diluted to adjust the polymer concentration to a value described below, and further cooled.

After the polymerization reaction is completed, the produced polymer is dissolved in the polymerization solvent at a predetermined polymer concentration.

Here, 1 polymer concentration refers to the weight of the produced polymer dissolved per 0 polymerization solvent Idol.

In the second step, first, a polymerization solvent is further added to the solution to dilute the solution so that the polymer concentration becomes 2 to 18 g/dl.

The amount of polymerization solvent added was too large, resulting in a polymer concentration of 2g/
If it is less than d1, the amount of solvent used will increase, leading to a decrease in productivity. Conversely, if the polymer concentration exceeds 18 g/d, polymer particles will adhere to each other and the particles will be damaged. Preferably, the monopolymer concentration is 3 to 8 g/djL.

When the polymer concentration of the solution is diluted and adjusted to 2 to 18 g/di, the solution is then cooled to 10 to 80 ° C. If the cooling temperature is less than 10 ° C., solidification of the solvent tends to occur. On the other hand, if the temperature exceeds 80°C, the polymer will not be sufficiently precipitated from the solvent. Preferably it is 30-50°C.

Through this second step, the polymer is obtained as an extremely fine powder, so a mechanical pulverization step for purification is not required, and the polymer can be sufficiently purified in the subsequent washing and purification step.

[Examples of the Invention] Example 1 88.0 g (0.5 mol) of 2.8-dichlorobenzonitrile and 2.8-dichlorobenzonitrile were placed in a polymerization vessel with an internal volume of 2, equipped with a distillation device, a stirrer, and an argon gas blowing tube. 7-hydroxynaphthalene? 9.3 g (0,495 mol), potassium carbonate 83.0 g (0.13 mol) 1 Add 0.5 fL of sulfolane as a polymerization solvent, 0.2 fL of toluene as an azeotropic solvent with water, and blow argon gas. The mixture was stirred and reacted at 180° C. for 2 hours, and the water produced was distilled off together with toluene. Then, the temperature was raised to 210°C and a reaction was carried out for 2 hours. The polymer concentration of the obtained polymer solution was 2
It was 5g/d.

Next, 0.5 Jl of sulfolane was added to this polymer solution to make the polymer concentration 12 g/d, and then cooled to 30° C. with stirring, and the precipitated polymer powder was collected separately.

The obtained powder was then washed three times with five portions of water and once with two portions of methanol, and dried to obtain 24 g (yield: 98%) of polycyanoaryl ether powder.

This polymer was prepared using p-chlorophenol as a solvent.
Reduced viscosity at 60°C of a solution with a concentration of 2 g/di [ηs
p/cl was 0.83 dIL/g.

Next, the average particle size of the obtained polymer powder was examined and found to be 40 to 60 microns.

In addition, in order to check the degree of purification of this polymer, the residual amount of potassium in the polymer was measured by atomic absorption method, and it was found to be 10 pp.
It was m. On the other hand, when the volume resistivity of the polymer powder was measured, it was found to be 1.7×10”Ω·C, confirming a high degree of purification.

Example 2 In place of 2,7-hydroxynaphthalene in Example 1, 54.5 g (0°485 mol) of hydroquinone was used.
and the amount of sulfolane added to the polymer solution after the polymerization reaction is 1 sentence, and the polymer concentration is 8.7 g/d.
A polymer powder was obtained in the same manner as in Example 1, except that cooling was performed. The yield of the obtained polycyanoaryl ether was 97 g (yield 87%), and the reduced viscosity of the obtained polymer was measured in the same manner as in Example 1.
The reduced viscosity [ηsp/cl] was 1.58 dl/g.

The average particle size of the obtained polymer powder was as fine as 40pII, and the residual amount of potassium in the polymer was 10pp. Ta.

Example 3 92.1 g (0,495 mol) of biphenol was used in place of 2,7-hydroxynaphthalene in Example 1, and the amount of sulfolane added to the polymer solution after the completion of the polymerization reaction was 1. The polymer concentration was 9.3 g/di.
A polymer powder was obtained in the same manner as in Example 1, except that cooling was performed. The yield of the obtained polycyanoaryl ether was 140 g (yield 98.8%), and the reduced viscosity of the obtained polymer was measured in the same manner as in Example 1, and it was found that the reduced viscosity [η sp/cl was 1 It was .27 d/g.

The average particle size of the obtained polymer powder was as fine as 401M1, the residual amount of potassium in the polymer was 10pp, and the volume resistivity was 2. It was confirmed that the purity was high.

[Effects of the Invention] As is clear from the above explanation, if the method for producing polycyanoarylether powder of the present invention is applied, there is no need for a mechanical pulverization process of the produced polymer as in the conventional method, and A much finer powder can be obtained than that obtained by the grinding process. Therefore, washing can be effectively performed in the subsequent purification step, and a powder with a high degree of purification can be obtained.

As a result, the obtained polymer has improved electrical properties, such as electrical insulation, so it can be applied as a material for mechanical parts of electrical and electronic equipment, and its industrial value is great. .

Claims (1)

[Claims] Dihalogenobenzonitrile and the following formula: MO-Ar-OM (In the formula, Ar is ▲a numerical formula, a chemical formula, a table, etc.▼,
▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲Mathematical formulas, chemical formulas,
There are tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼
(M represents an alkali metal) is reacted with an alkali metal salt of a dihydric phenol represented by the following in the presence of a polymerization solvent to produce a polymer; Add the polymerization solvent to bring the polymer concentration to 2 to 16 g.
/dl and then cooling to 10 to 80°C.