JPH0762085A - Method for producing polycyanoaryl ether resin - Google Patents

Abstract

(57) [Summary] [Objective] In producing a polycyanoaryl ether resin, a high molecular weight can be achieved in a short time, and a polycyanoaryl ether resin having a low melting point and excellent moldability is obtained. The manufacturing method which can be used is provided. [Structure] A step of reacting dihalogenobenzonitrile with resorcin and an alkali metal compound in the presence of a solvent to form an oligomer (first step), and then the obtained reaction product is represented by the following formula (I): Chemical 1] (In the formula, Y represents a group containing an electron-withdrawing group.)
A method for producing a polycyanoaryl ether resin, which comprises a step of reacting a difluoro compound represented by (second step).

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a polycyanoaryl ether resin. More specifically, the present invention has a higher molecular weight than conventional polycyanoaryl ether-based resins, and is excellent in mechanical strength, heat resistance, chemical resistance and the like, and a polymer having excellent moldability is obtained, In addition, the present invention relates to a method for producing a polycyanoaryl ether-based resin that can increase the productivity because it has a high molecular weight.

The polycyanoaryl ether resin obtained by the present invention is used as a high-performance engineering resin or the like in various polymer material application fields, for example, electronic / electrical equipment fields, mechanical fields, automobile fields, aviation fields, etc. Can be preferably used as.

[0003]

2. Description of the Related Art Engineering plastics are used in a wide range of fields to reduce the size and weight of products.
One type of engineering plastic is polycyanoaryl ether, which is a resin that is extremely excellent in mechanical strength and heat resistance because it is crystalline.

Conventionally, various polycyanoaryl ethers have been disclosed. For example, JP-A-47-14270 discloses a method of reacting dinitrobenzonitrile with an alkali metal salt of a dihydric phenol in a solvent. , A method for obtaining polycyanoaryl ethers is disclosed. However, in this method, when resorcin was used as the dihydric phenol, a high-molecular weight polymer was not obtained, and when an equal mixture of bisphenol A and resorcin was used as the dihydric phenol, it was obtained. The polymer has a high molecular weight, but has a low thermal decomposition initiation temperature of 390 ° C., which makes it difficult to say that it has sufficient heat resistance.

In order to solve this, the present inventor has proposed a method of reacting an alkali metal salt of resorcin with dihalogenobenzonitrile in a solvent (JP-A-62-2).
23226). The polycyanoaryl ether produced by this method has a high molecular weight and is excellent in heat resistance, however, in this production method, the polymerization time for obtaining a polymer having a desired high molecular weight is long and the productivity is low. There was a problem.

Therefore, as a further improved method, the present inventor has proposed a method of reacting an alkali metal salt of resorcin with dihalogenobenzonitrile and then reacting the obtained reaction product with difluorobenzonitrile. (See Japanese Examined Patent Publication No. 4-8449). According to this method, it is possible to increase the molecular weight in a relatively short time, but there is a problem that the polycyanoaryl ether obtained has a high melting point and the moldability is not always sufficient.

[0007]

The object of the present invention is to provide a polymer having a sufficiently high molecular weight and excellent mechanical strength and chemical resistance.
It is an object of the present invention to provide a production method capable of extremely easily and efficiently producing a polycyanoaryl ether resin having excellent heat resistance and moldability.

[0008]

Means for Solving the Problems As a result of repeated studies to solve the above problems, the present inventor first produced a polymer by the reaction between dihalogenobenzonitrile and resorcin, and then the reaction with high reactivity was performed. By reacting a difluoroaromatic compound having a specific structure with the above-mentioned polymer, it was found that a polymer having a high melting point and a low melting point and having excellent moldability can be obtained, and based on this finding, The invention was completed.

That is, according to the present invention, in a method for producing a polycyanoaryl ether resin by reacting dihalogenobenzonitrile with resorcin, the dihalogenobenzonitrile is reacted with resorcin and an alkali metal compound in the presence of a solvent. The step (first step) and then the obtained reaction product are represented by the following formula (I)

[0010]

[Chemical 3] (In the formula, Y represents a group containing an electron-withdrawing group.)
The present invention provides a method for producing a polycyanoaryl ether-based resin, which comprises a step (second step) of reacting a difluoro compound represented by

In the method of the present invention, first, in the first step, dihalogenobenzonitrile, resorcin and an alkali metal compound are dissolved in a solvent described below and reacted under the conditions described below.

The dihalogenobenzonitrile used in the present invention has a halogen atom in the 2,4-position or 2,6-position.
Those linked to the position are preferred. The halogen atom in dihalogenobenzonitrile is not particularly limited,
Usually, a chlorine atom and a fluorine atom are preferable, and a chlorine atom is particularly preferable. Specific examples of preferable dihalogenobenzonitrile include 2,4-dichlorobenzonitrile and 2,2-dichlorobenzonitrile.
6-dichlorobenzonitrile may be mentioned.

These dihalogenobenzonitriles may be used alone or in combination of two or more. Preferred examples of use include, for example, use of 2,4-dichlorobenzonitrile and / or 2,6-dichlorobenzonitrile, 2,4-dichlorobenzonitrile and / or
Alternatively, a combination of 2,6-dichlorobenzonitrile and one or more difluorobenzonitriles may be used.

As the alkali metal compound used in the present invention, any compound can be used as long as it can convert resorcin into an alkali metal salt. Usually, an alkali metal carbonate, Hydrogen carbonate, hydroxide and the like are preferably used, and among them, carbonate is particularly preferable. Examples of the alkali metal include lithium, sodium, potassium, rubidium and cesium, and among them, sodium and potassium are particularly preferable. Specific preferred examples of these alkali metal compounds include sodium carbonate, sodium hydrogen carbonate, potassium carbonate, potassium hydrogen carbonate and the like, with sodium carbonate being particularly preferred.

These alkali metal compounds may be used alone or in combination of two or more.

The dihalogenobenzonitrile is preferably used in a molar ratio (dihalogenobenzonitrile / resorcinol) of usually 0.95 to the amount of resorcin used.
It is preferable to select it in the range of 1.00, particularly 0.98 to 1.00.

A preferable ratio of the alkali metal compound used is an equivalent ratio of the ratio of the alkali metal compound to the amount of the dihalogenobenzonitrile used, usually 1.0 to 3.0,
More preferably 1.0 to 2.0, particularly preferably 1.05.
It is appropriate to select in the range of 1.20. Here, for dihalogenobenzonitrile, 1 mol is calculated as 2 equivalents, while for alkali metal compounds, the usual calculation is performed. For example, in the case of alkali metal carbonate, 1 mol is equivalent to 2 equivalents, and alkali metal hydrogen carbonate is calculated. In the case of salts and hydroxides, 1 mol shall be calculated as 1 equivalent.

In order to proceed the reaction of the first step, instead of using resorcin and the above alkali metal compound, the following formula obtained by the reaction of resorcin and the above alkali metal compound is used.

[0019]

[Chemical 4] (However, in the formula, M represents an alkali metal.) An alkali metal salt of resorcin represented by the formula may be used. When such an alkali metal salt of resorcin is used, the preferable use ratio of dihalogenobenzonitrile is the same as above.
The molar ratio (dihalogenobenzonitrile / resorcinol) to the amount of the alkali metal salt of resorcinol is usually
It is preferable to select in the range of 0.95 to 1.00, particularly 0.98 to 1.00.

The solvent used in this reaction is not particularly limited as long as the polymerization reaction in the first step proceeds smoothly, and various solvents known in the art for synthesizing this type of polymer are used. Can be used. Usually, a neutral polar solvent or a mixed solvent containing it as a main component, for example, a mixed solvent with an aromatic solvent such as toluene, etc. is preferably used.

Preferred examples of the above neutral polar solvent include N-methylpyrrolidone (NMP) and N-
Ethylpyrrolidone, N, N'-dimethylimidazolidinone (DMI), N-methylcaprolactam, N, N-dimethylacetamide (DMAc), N, N-diethylacetamide, N, N-diethyleneacetamide, dimethylformamide (DMF) And amide solvents such as diethylformamide.

The preferred ratio of the solvent used cannot be uniformly determined because it depends on the type of solvent used and other conditions such as the type and amount of the difluoro compound added in the second step subsequent to the first step. When the amide solvent is used, the total molar amount of the polymerization reaction raw materials to be used,
{(Dihalogenobenzonitrile) + (resorcin) +
The ratio of ((alkali metal compound)) or {(dihalogenobenzonitrile) + (alkali metal salt of resorcin)} per 1000 ml of amide solvent is usually in the range of 0.1 mol / 1000 ml to 10 mol / 1000 ml. It is preferable to select the following ratio.

By the reaction in the first step, the following formula (I
I)

[0024]

[Chemical 5] A polymer having a repeating unit represented by The molecular weight of this polymer is not particularly limited, and can be appropriately determined according to the target molecular weight of the finally obtained polycyanoaryl ether resin according to the following reaction conditions.

The reaction in the first step is usually 150 to 3
It can be suitably carried out at a temperature of 50 ° C., preferably 190 to 220 ° C. If the temperature is lower than 150 ° C, it takes a long time for the polymerization reaction to proceed, while the reaction temperature is set to 350 ° C.
If the temperature is higher than 0 ° C, the resulting polymer is apt to be thermally deteriorated.

The reaction time varies depending on conditions such as the reaction temperature, the type of solvent, the desired polymer and the molecular weight of the final polycyanoaryl ether resin, and therefore cannot be uniformly determined, but usually about 1 to 5 hours. It is also economical and preferable.

In the reaction of the first step, other components than the above components, such as a molecular weight regulator, a branching agent and a reaction accelerator, or other components, may be used as needed within a range that does not impair the object of the present invention. A monomer component and the like may be appropriately added or coexisted.

When the molecular weight regulator is added in the first step,
The molecular weight regulator preferably used is, for example, the following formula:

[0029]

[Chemical 6] (However, in the formula, R ¹ represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aralkyl group, or a cyano group.). Specific examples of such a monohydric phenol include phenol, cresol, p-tert-butylphenol, cumylphenol, isopropylphenol, methoxyphenol, and cyanophenol. The addition amount of these molecular weight modifiers can be appropriately determined according to the molecular weight of the intended polycyanoaryl ether resin.

Then, the reaction product obtained in the first step, that is, the oligomer is reacted with the difluoro compound represented by the above formula (I) to obtain the target polycyanoaryl ether resin (first 2 steps). The resulting polycyanoaryl ether resin has the above formula (I
The polymer having a repeating unit represented by I) is represented by the following formula (III).

[0031]

[Chemical 7] (However, in the formula, Y has the same meaning as described above.) And has a structure bonded by a group.

In the present invention, in the first step, a polymer is first produced, and then in the second step, a highly reactive difluoro compound is used to further bond the polymer to increase the molecular weight in a short time. Can be achieved. In addition, dichlorobenzonitrile is usually preferably used in the reaction in the first step, but when dichlorobenzonitrile is used, the reactivity is not necessarily high, and only a reaction in the first step increases the molecular weight. It takes time and the productivity is poor. However, according to the method of the present invention, the reaction in the first step may be carried out to such an extent that a polymer having a relatively low molecular weight is formed.
Since high molecular weight can be promoted in a short time in the step, even when dichlorobenzonitrile is used in the first step, a high molecular weight polycyanoaryl ether resin can be obtained with good productivity. Moreover, since the obtained polycyanoaryl ether-based resin has the structure represented by the formula (III) in the polymer chain, it has a lower melting point than that of the conventional polycyanoaryl ether and is excellent in moldability. Become.

In the formula (I) representing a difluoro compound, Y is not particularly limited as long as it is a divalent group containing an electron-withdrawing group, and preferable specific examples of Y include:

[0034]

[Chemical 8] (However, R represents an alkyl group having 1 to 13 carbon atoms or an aryl group having 6 to 13 carbon atoms.).

The difluoro compounds may be used alone or in combination of two or more.

The amount of the above-mentioned difluoro compound used depends on the molecular weight of the target polycyanoaryl ether resin, the first
It depends on the molecular weight and the like of the polymer obtained in the step and is not uniformly determined, but usually, the amount of resorcin used is 1 mol, and the difluoro compound is 0.001 to 0.05 mol,
Preferably, the relative amount is 0.005-0.02 mol.

The reaction in this second step is usually the first step.
It is carried out by adding a solution prepared by dissolving the above-mentioned difluoro compound in the above-mentioned solvent to the solution of the reaction product obtained in the step.

This reaction can be suitably carried out usually in the range of 150 to 350 ° C, preferably 190 to 220 ° C. Here, if the temperature is lower than 150 ° C., the reaction may not proceed due to the precipitation of the polymer, while if the reaction temperature is higher than 350 ° C., the generated polycyanoaryl ether-based resin is likely to be thermally deteriorated. May cause problems.

The reaction time cannot be uniformly set because it depends on the reaction temperature, the type of solvent, the intended degree of high molecular weight and the like, but it is usually economical to set the reaction time to about 30 minutes to 5 hours. Yes, it is preferable.

In the reaction of the second step as well, other components than the above-mentioned various components such as a molecular weight regulator, a branching agent and a reaction accelerator may be added, if necessary, within a range not impairing the object of the present invention. Alternatively, other monomer components may be added or coexistent.

When the molecular weight modifier is added in the second step, it is preferable to use a monohalogenated hydrocarbon. Examples of such monohalogenated hydrocarbons include methyl chloride, 2-fluorobenzonitrile, 4-fluorobenzonitrile, 2-fluorobenzophenone, 4-chlorodiphenyl sulfone and the like.

The amount of the molecular weight modifier used in the second step is appropriately determined according to the molecular weight of the desired polycyanoaryl ether resin.

The polycyanoaryl ether resin thus obtained is separated from the reaction product mixture by a conventional method,
It can be recovered and purified to obtain a polymer having a desired degree of purification. For example, the polymer is separated and recovered by removing the solvent and the like, and washed with an appropriate washing liquid such as methanol or hot water, or if necessary, an alkaline component removing agent such as oxalic acid is removed in this washing step. After the necessary post-treatment such as desalting with
Furthermore, a method of drying appropriately is preferably adopted. At that time, a method of enhancing the cleaning effect by appropriately pulverizing the polymer can also be suitably adopted.

[0044]

The present invention will be described more specifically below by showing Examples of the present invention and Comparative Examples thereof, but the present invention is not limited to these Examples.

Example 1 25.754 g of 2,6-dichlorobenzonitrile was placed in a 300 ml reactor equipped with a stirrer, a Dean Stark trap filled with toluene, and an argon gas inlet tube.
(0.15 mol) and resorcin 16.516 g (0.15 mol)
Mol), sodium carbonate 17.488 g (0.165 mol), N-methylpyrrolidone 150 ml and toluene 1
0 ml was charged and dissolved at room temperature. Then 20
The reaction was carried out at 0 ° C. for 3 hours (first step), and while heating and stirring, 4,4′-difluorodiphenyl sulfone 0.483 was added.
After adding g (0.0019 mol), the mixture was further reacted at 200 ° C. for 3 hours (second step).

After cooling, the product is ground in methanol,
It was washed with water and methanol in this order to obtain 32 g of a polymer powder (yield 97%).

The sum of the reaction times of the first step and the second step,
Reduced viscosity [η _sp / c], glass transition temperature (Tg), melting point (T) of the obtained polymer in a solution of p-chlorophenol at a concentration of 0.2 g / dl at 60 ° C.
m), thermal decomposition start temperature (5% weight loss temperature in air) (T
d) is shown in Table 1.

Example 2 Instead of the 4,4'-difluorodiphenyl sulfone used in Example 1, 2-phenyl-4,6-bis (4-fluorophenyl) -1,3,5-triazine 0.656 g
The reaction was carried out in the same manner as in Example 1 except that (0.0019 mol) was used. The yield of the obtained polymer was 32.3 g (yield 98%).

The sum of the reaction times of the first step and the second step,
Reduced viscosity [η _sp / c], glass transition temperature (Tg), melting point (T) of the obtained polymer in a solution of p-chlorophenol at a concentration of 0.2 g / dl at 60 ° C.
m), thermal decomposition start temperature (5% weight loss temperature in air) (T
d) is shown in Table 1.

Comparative Example 1 The amount of 2,6-dichlorobenzonitrile used was 26.05.
The reaction was performed in the same manner as in Example 1 except that 9 g (0.1515 mol) was used, 4,4'-difluorodiphenyl sulfone was not used, and the total reaction time was 6 hours. The yield of the obtained polymer was 31 g (yield 96%).

The reaction time was 6% of a solution of the obtained polymer in a concentration of 0.2 g / dl using p-chlorophenol as a solvent.
Reduced viscosity at 0 ° C. [η _sp / c], glass transition temperature (Tg), melting point (Tm), thermal decomposition start temperature (in air, 5
The% weight loss temperature (Td) is shown in Table 1.

[0052]

[Table 1]

The polymers obtained in Examples 1 and 2 according to the present invention have a higher reduced viscosity than the polymer obtained in Comparative Example 1 by the conventional method, and have sufficiently increased the molecular weight in a short time. I understand. Further, the glass transition temperature and the thermal decomposition starting temperature, especially the thermal decomposition starting temperature are sufficiently high, and the heat resistance is excellent. Further, although the polymers obtained in Examples 1 and 2 are excellent in heat resistance, the melting point is lower than that of the polymer obtained in Comparative Example 1 and the moldability is improved.

[0054]

According to the method of the present invention, a simple operation of adding a highly reactive difluoroaromatic compound having a specific structure to a polymerization reaction system comprising dihalogenobenzonitrile, resorcin and an alkali metal compound. Thus, a polycyanoaryl ether resin having a high molecular weight can be obtained in a short reaction time. Further, the obtained polycyanoaryl ether resin has high mechanical strength due to its high molecular weight and is excellent in heat resistance as well as derived from the above specific difluoroaromatic compound in the polycyanoaryl ether chain. Since it has a structural unit that has such a structure, it is a polymer having a low melting point and excellent moldability, and can be suitably used as various molding materials.

Claims (2)

[Claims] 1. A method for producing a polycyanoaryl ether resin by the reaction of dihalogenobenzonitrile and resorcin, wherein the step of reacting dihalogenobenzonitrile with resorcin and an alkali metal compound in the presence of a solvent (first Process), and then the reaction product obtained by the following formula (I) (In the formula, Y represents a group containing an electron-withdrawing group.)
A process for producing a polycyanoaryl ether-based resin, which comprises a step (second step) of reacting a difluoro compound represented by 2. Y in the general formula (I) is (However, R represents an alkyl group having 1 to 13 carbon atoms or an aryl group having 6 to 13 carbon atoms.) The method for producing a polycyanoaryl ether resin according to claim 1, which is a group selected from the group consisting of: