JP2692390B2 - Method for producing polyphenylene sulfide sulfone - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing polyphenylene sulfide sulfone, and more particularly to a method for obtaining polyphenylene sulfide sulfone having a high molecular weight and good thermal stability in a molten state.

[0002]

2. Description of the Related Art Polyphenylene sulfide sulfone is
Since it is a thermoplastic type polymer and can be molded easily and efficiently to obtain a product of almost any shape, it is suitable for mass production as a molding resin. In order to use the polymer in industrial applications such as electric parts, electric wire coatings, automobile parts, etc., it is desired to improve the mechanical strength and heat resistance of the molded product. For that purpose, a high molecular weight polymer is used. It was necessary to manufacture.

Conventionally, in such cases, a method has been adopted in which the molecular weight of the polymer is increased by using an alkali metal carboxylate or free water as a polymerization aid under the polymerization reaction conditions. That is, contacting a dihalo aromatic sulfone and an alkali metal sulfide in an organic amide solvent,
It was possible to polymerize high molecular weight polyphenylene sulfide sulfones by adding alkali metal carboxylates or free water during the reaction for a sufficient time at temperatures ranging from about 170 ° C to 240 ° C.
An example of such a technique is disclosed in Japanese Patent Publication No. 53-25879.
It is disclosed in Japanese Examined Patent Publication No. 53-25880.

[0004]

However, in recent years, when polyphenylene sulfide sulfone is used in special industrial fields such as aircraft parts and space-related parts, it is required to have higher mechanical strength and excellent heat resistance than before. It was For that purpose, it is necessary to produce a polymer having a higher molecular weight than the polymer obtained by the conventional method. In addition, in the polyphenylene sulfide sulfone obtained by the conventional method, not only the viscosity of the polymer in the molten state changes greatly with time, but also the phenomenon of foaming at the time of melting was observed.
Due to these factors, the range of processing conditions (mold temperature, injection pressure, etc.) applicable for injection molding is extremely narrow,
There is a problem that defects in the appearance of the molded product are likely to occur.

[0005]

The present invention has the following constitution in order to solve the problems of the prior art. That is, the present invention uses (1) an organic amide as a solvent,
In the method of polymerizing polyphenylene sulfide sulfone by reacting an alkali metal sulfide with a dihaloaromatic sulfone as a raw material in the presence of an alkali metal carboxylate and / or free water, when the raw materials are mixed to start a polymerization reaction. In the method for producing polyphenylene sulfide sulfone, which is characterized by holding in the temperature range of 90 ° C to 150 ° C for 60 minutes or more, and then heating to a temperature higher than that, (2) mixing raw materials to carry out a polymerization reaction. At the time of starting, after maintaining in the temperature range of 90 ° C. to 150 ° C. for 60 minutes or more, a mode of heating up to about 180 ° C. to 220 ° C. and
(3) At the time of mixing the raw materials and starting the polymerization reaction, 90 ° C to
It includes a mode of heating and raising the temperature at a low rate of 1 ° C./min or less in the temperature range of 150 ° C.

Examples of the dihaloaromatic sulfone in the method of the present invention include bis (p-fluorophenyl) sulfone, bis (p-chlorophenyl) sulfone, bis (p-p-fluorophenyl) sulfone.
Bromophenyl) sulfone, bis (p-iodophenyl) sulfone, p-fluorophenyl p-bromophenyl sulfone, and the like, and mixtures thereof.

Alkali metal sulfides that can be used in the method of the present invention include sodium sulfide, potassium sulfide, rubidium sulfide, cesium sulfide, and mixtures thereof.
The alkali metal sulfide can be used in anhydrous form, hydrate, or as an aqueous mixture.

Examples of alkali metal carboxylates that can be used in the method of the present invention include lithium acetate, sodium acetate, potassium acetate, and the like, and mixtures thereof.

The organic amide which can be used in the process of the present invention should be substantially liquid at the reaction temperature and pressure used. The amide may be cyclic or acyclic, and examples thereof include formamide, acetamide, N-methylformamide, N, N-dimethylformamide, N, N-dimethylacetamide, N-ethylpropionamide. , N, N-dipropylbutyramide, 2
-Pyrrolidone, N-methyl-2-pyrrolidone, ε-caprolactam, N-methyl-ε-caprolactam, etc.,
And mixtures thereof.

Although the molar ratio of dihaloaromatic sulfone to alkali metal sulfide can vary over a considerable range, it is generally preferred to be in the range of 1: 1 to 1.1: 1. The amount of organic amide can vary over a wide range but is generally preferred in the range of 500 g to 2000 g per gram-mole of alkali metal sulfide.

Further, it is preferable to add an alkali metal carboxylate and free water as a polymerization aid, in which case the amount of alkali metal carboxylate is in a considerable range in the molar ratio of alkali metal carboxylate to alkali metal sulfide. It can change over time. Generally, it is preferable to be within the range of 0.1: 1 to 1.5: 1. Also, the amount of free water can vary over a considerable range in the molar ratio of free water to organic amide. Generally, it is preferably within the range of 0.5: 1 to 1.2: 1.

Although the detailed mechanism of the polymerization reaction is not known, according to the present invention, by reacting at a temperature lower than the conventional reaction temperature for a sufficient time in the initial stage of the polymerization reaction, a side reaction that occurs at the conventional reaction temperature The reaction and decomposition reaction can be suppressed. That is, when starting the polymerization reaction by mixing the raw materials, while maintaining a sufficient pressure to maintain the liquid phase conditions,
After being kept in the temperature range of 90 ° C. to 150 ° C. for a sufficient time of 60 minutes or more, about 180 ° C. to 22 ° C. corresponding to the conventional reaction temperature.
By raising the temperature to 0 ° C. and holding at that temperature for a time sufficient to complete the reaction, preferably in the range of about 1 hour to about 6 hours, side reactions and decomposition reactions that occur at conventional reaction temperatures can be carried out. It is possible to obtain a polymer that is suppressed and has a high molecular weight and a low content of oligomer components. By such slow heating at low temperature, the side reaction of dihalogenated aromatic sulfone is suppressed, the production of low molecular weight substances involved in thermal decomposition is reduced, and the molecular weight distribution becomes sharp on the polymer side. That is, a product having a high average molecular weight can be obtained.

The polymer produced by the method of the present invention has a higher intrinsic viscosity than the polymer produced by the conventional method.
Melt index is low at a load of 5 kg at 3.3 ° C, and there are few oligomer components extracted with acetone using a Soxhlet leacher. These facts support the fact that there is no foaming phenomenon at the time of melting, the change in viscosity with time at high temperature is small, and the like. 90 ℃ ~ 150 ℃
As a method of maintaining the temperature range for 60 minutes or more for a sufficient time, a certain constant temperature within the range of 90 ° C to 150 ° C, preferably a certain constant temperature within the range of 100 ° C to 130 ° C, is maintained for a sufficient time. Method, or 90 ℃ ~ 150 ℃
The same effect can be obtained by using the method of heating and raising the temperature at a low speed of 1 ° C./min or less in the temperature range.

[0014]

The present invention will be described with reference to the following examples, but the present invention is not limited thereto. As an index for evaluating the molecular weight of the polymer, a value of intrinsic viscosity measured using N-methyl-2-pyrrolidone as a solvent and a melt index measured with a load of 5 kg after holding at a temperature of 343.3 ° C. for 5 minutes The value of was used. It can be judged that the higher the measured value of the intrinsic viscosity and the smaller the measured value of the melt index, the higher the molecular weight. In order to quantify the oligomer components contained in the polymer, a method of extracting with a Soxhlet leaching apparatus using acetone as a solvent was used.

As an index for evaluating the thermal stability of the polymer in the molten state, the value of melt index measured at a load of 5 kg after holding at 343.3 ° C. for 30 minutes and 343.3.
After holding at 5 ° C for 5 minutes, the ratio of melt index values measured under the same load was used. It can be judged that the closer the ratio is to 1, the more excellent the thermal stability is. In addition, the polymer is
A method of visually observing whether or not foaming occurs from the surface of the molten polymer when melted at a temperature of 3.3 ° C. was also used as an index for evaluating thermal stability.

Comparative Example 1 52.0 kg of sodium sulfide aqueous solution (purity 60%, 0.
4kg-mol), 16.4kg (0.2kg-mol) sodium acetate
Um, 117.0 kg (0.407 kg-mol) of bis (p-
Chlorophenyl) sulfone, 440 kg (4.4 kg-mol)
N-methyl-2-pyrrolidone, 54 kg (3.0 kg-mo
l) ion-exchanged water, 1m with a stirrer ^ThreeIn the reaction tank
Then, the gas phase inside the tank was replaced with nitrogen and the reaction tank was replaced.
It was sealed. At the rate of about 2.8 ° C / min.
Heating up from about 90 ℃ to 200 ℃, 190 ~
It was kept at a temperature of 120 ° C. for about 4 hours. The reaction product is 60
Wash with ion-exchanged water at a temperature of ~ 80 ° C 7 times, then dry to 7
7 kg of amorphous polyphenylene sulfide sulfone was obtained.
Was.

The measured intrinsic viscosity of the polymer is 0.
22 dl / g, melt index measured after holding at 343.3 ° C. for 5 minutes was 92 kg / 10 minutes, oligomer component quantitative value was 2.3 wt%, melt index measured after holding at 343.3 ° C. for 30 minutes And the value of 343.3
The ratio to the value of the melt index measured after holding at 5 ° C for 5 minutes was 0.53, and a phenomenon of foaming was observed when melted at 343.3 ° C.

Example 1 As in Reference Example 1, 52.0 kg of sodium sulfide aqueous solution (pure content 60%, 0.4 kg-mol), 16.4 kg (0.
2 kg-mol) sodium acetate, 117.0 kg (0.40
7 kg-mol) bis (p-chlorophenyl) sulfone, 4
40 kg (4.4 kg-mol) of N-methyl-2-pyrrolidone and 54 kg (3.0 kg-mol) of ion-exchanged water were charged into a 1 m ³ reaction tank equipped with a stirrer, and then the gas phase in the tank was charged. Was replaced with nitrogen and the reaction vessel was sealed. The mixture in the tank is heated and heated at a rate of about 2.8 ° C./minute from about 90 ° C. to 120 ° C., and held at a temperature of 115 to 125 ° C. for about 1 hour, and then about 2.8 ° C./minute. The temperature was raised to a temperature of about 200 ° C. at a speed and kept at a temperature of 190 to 210 ° C. for about 150 minutes.

The reaction product was washed 7 times with ion-exchanged water at a temperature of 60 to 80 ° C. and dried to obtain 82 kg of amorphous polyphenylene sulfide sulfone. The polymer produced had an intrinsic viscosity of 0.37 dl / g and a melt index of 3 after holding at 343.3 ° C. for 5 minutes.
2kg / 10min, quantitative value of oligomer component is 1.0wt%, 3
The ratio of the melt index value measured after holding at 43.3 ° C. for 30 minutes and the melt index value measured after holding at 343.3 ° C. for 5 minutes was 1.10, and 3
No foaming phenomenon was observed when melted at a temperature of 43.3 ° C.

Example 2 As in Reference Example 1, 52.0 kg of sodium sulfide aqueous solution (pure content 60%, 0.4 kg-mol), 16.4 kg (0.
2 kg-mol) sodium acetate, 117.0 kg (0.40
7 kg-mol) bis (p-chlorophenyl) sulfone, 4
40 kg (4.4 kg-mol) of N-methyl-2-pyrodrine and 54 kg (3.0 kg-mol) of ion-exchanged water were charged into a 1 m ³ reaction tank equipped with a stirrer, and then the gas phase part in the tank was charged. Was replaced with nitrogen and the reaction vessel was sealed. After heating the temperature of the mixture in the tank at a rate of about 0.8 ° C / minute to a temperature of about 90 ° C to 150 ° C, the temperature is raised to about 200 ° C at a rate of about 2.8 ° C / minute. It was warmed and held at a temperature of 190-210 ° C for about 150 minutes. The reaction product was washed 7 times with ion-exchanged water at a temperature of 60 to 80 ° C. and dried to obtain 81 kg of an amorphous polyphenylene sulfide sulfone.

With respect to the produced polymer, the measured intrinsic viscosity was 0.38 dl / g, the melt index was measured after holding at 343.3 ° C. for 5 minutes, the melt index was 30 g / 10 minutes, and the quantitative value of the oligomer component was 1.1 wt%. The ratio of the melt index value held at 343.3 ° C. for 30 minutes to the melt index value measured after holding at 343.3 ° C. for 5 minutes was 1.12, and the melting index was 343.3 ° C. No foaming phenomenon was observed at the time.

[0022]

According to the present invention, the following effects can be obtained. (1) Since polyphenylene sulfide sulfone having a higher molecular weight than that obtained by the conventional production method can be obtained, mechanical strength and heat resistance of a molded product can be improved.

(2) Since polyphenylene sulfide sulfone having more excellent thermal stability in a molten state can be obtained than polyphenylene sulfide sulfone obtained by the conventional production method, the range of processing conditions applicable to molding is wide, Good operability in molding.

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Claims (3)

(57) [Claims] 1. A method of polymerizing polyphenylene sulfide sulfone by reacting an alkali metal sulfide with a dihalogenated aromatic sulfone as a raw material in the presence of an organic amide as a solvent in the presence of an alkali metal carboxylate and / or free water. When the raw materials are mixed and the polymerization reaction is started, the temperature is controlled to 90 ° C. to 150 ° C. by 60 ° C.
A method for producing a polyphenylene sulfide sulfone, which is characterized by holding for more than a minute and then heating to a temperature higher than that. 2. When mixing raw materials and initiating a polymerization reaction,
After holding in the temperature range of 90 ° C to 150 ° C for 60 minutes or more,
The method for producing a polyphenylene sulfide sulfone according to claim 1, wherein the temperature is raised to 180 ° C to 220 ° C. 3. When mixing raw materials and initiating a polymerization reaction,
The method for producing polyphenylene sulfide sulfone according to claim 1, wherein heating is performed at a low rate of 90 ° C. to 150 ° C. at an average rate of 1 ° C./minute or less.