JP2002265602A - Method for producing polyaryrene sulfide having stable quality - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a polyarylene sulfide, capable of reducing the variation of molecular weight of the produced polyarylene sulfide. SOLUTION: This method for producing the polyarylene sulfide by reacting lithium sulfide produced by de-hydrogen sulfide of lithium hydro sulfide, with dihalogenated aromatic compound, is characterized by using lithium sulfide particles having <=50 μm mean particle diameter as the above lithium sulfide.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing polyarylene sulfide. More specifically, the present invention relates to a method for producing stabilized polyarylene sulfide in which the fluctuation of the molecular weight is remarkably reduced in the fields of electronic and electric materials, the field of automobiles, and the field of heat-resistant materials.

[0002]

2. Description of the Related Art Polyarylene sulfide (hereinafter referred to as PA)
S), among which polyphenylene sulfide (hereinafter sometimes referred to as PPS) is particularly excellent in mechanical strength, heat resistance, flame retardancy, solvent resistance and the like, and has good electrical characteristics and high rigidity. It is widely known as engineering plastics, and is widely used as a material for automobile parts, electronic / electric equipment parts, and mechanical parts. Conventionally, a dihalogen aromatic compound such as p-dichlorobenzene and a sodium salt such as sodium sulfide are prepared in an aprotic organic solvent such as N-methyl-2-pyrrolidone (hereinafter, sometimes referred to as NMP). Has generally been used. However, in this method, sodium halide is produced as a by-product, and since this sodium halide is insoluble in a solvent such as NMP, it is taken into the PAS. Even after the polymerization, the PAS is washed with a large amount of water. Sodium halide in PAS could not be sufficiently removed.
Therefore, attention has been paid to a method of performing polymerization using a lithium salt instead of a sodium salt. In a method for producing a PAS using such a lithium salt, for example, lithium hydroxide and hydrogen sulfide are reacted in an aprotic organic solvent to produce lithium hydrosulfide, and then the reaction solution is dehydrosulfided. It is characterized in that the lithium sulfide generated by the use is used as a sulfur source.

[0003]

In the method for producing PAS using a lithium salt as described above, lithium sulfide is synthesized by a dehydrogenation reaction of lithium hydrosulfide as described below. The deposited lithium sulfide is
The average particle size was usually about 100 μm or more. 2LiSH → Li ₂ S + H ₂ S and
Using lithium sulfide having a large average particle size as described above,
When AS is produced, the concentration of the feed to the polycondensation tank becomes unstable, and the concentration becomes non-uniform in the polycondensation tank. Therefore, there is a problem that the molecular weight of the produced PAS fluctuates greatly. . The present invention has been made in view of the above problems. That is, the present invention provides a PA for reacting lithium sulfide produced by dehydrogenation of lithium hydrosulfide with a dihalogenated aromatic compound.
An object of the present invention is to provide a method for producing S, which can significantly reduce the variation in the molecular weight of PAS to be produced.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies in view of the above problems, and as a result, used lithium sulfide used in the production of PAS in the form of finely divided particles.
It has been found that the above object of the present invention can be achieved by controlling the reaction. The present invention has been completed based on such findings. That is, the present invention relates to a method for producing polyarylene sulfide by reacting lithium sulfide generated by dehydrogenation of lithium hydrosulfide with a dihalogenated aromatic compound, wherein the lithium sulfide has an average particle diameter of 50 μm or less. An object of the present invention is to provide a method for producing polyarylene sulfide, characterized by using lithium particles.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. The method for producing polyarylene sulfide of the present invention uses lithium sulfide produced by dehydrogenation of lithium hydrosulfide, particularly lithium sulfide particles having an average particle size of 50 μm or less. The lithium sulfide is formed by reacting lithium hydroxide and hydrogen sulfide in an aprotic organic solvent to generate lithium hydrosulfide, and then dehydrogenating this reaction solution. This will be specifically described below.

[0006] In the present invention, lithium hydroxide and hydrogen sulfide are reacted in an aprotic organic solvent.
Produces lithium hydrosulfide (LiSH). As the aprotic organic solvent, generally, aprotic polar organic compounds (for example, amide compounds, lactam compounds, urea compounds, organic sulfur compounds, cyclic organic phosphorus compounds, etc.)
Can be suitably used as a single solvent or as a mixed solvent. Among these aprotic polar organic compounds, examples of the amide compound include N, N-dimethylformamide, N, N-diethylformamide, N, N-dimethylacetamide, N, N
-Diethylacetamide, N, N-dipropylacetamide, N, N-dimethylbenzoic acid amide.

The lactam compound includes, for example, caprolactam, N-methylcaprolactam, N
N-alkylcaprolactams such as -ethylcaprolactam, N-isopropylcaprolactam, N-isobutylcaprolactam, N-normalpropylcaprolactam, N-normalbutylcaprolactam, N-cyclohexylcaprolactam, N-methyl-2-pyrrolidone (NMP), N -Ethyl-2-pyrrolidone, N-isopropyl-2-pyrrolidone, N-isobutyl-2-pyrrolidone, N-n-propyl-2-pyrrolidone, N-n-butyl-2-pyrrolidone, N-cyclohexyl-
2-pyrrolidone, N-methyl-3-methyl-2-pyrrolidone, N-ethyl-3-methyl-2-pyrrolidone, N-methyl-34,5-trimethyl-2-pyrrolidone, N-methyl-2-piperidone, N -Ethyl-2-piperidone,
N-isopropyl-2-piperidone, N-methyl-6
Methyl-2-piperidone, N-methyl-3-ethyl-2
-Piperidone and the like.

The urea compound includes, for example, tetramethyl urea, N, N'-dimethylethylene urea, N, N'-dimethylpropylene urea and the like. Further, as the organic sulfur compound,
For example, dimethylsulfoxide, diethylsulfoxide, diphenylsulfone, 1-methyl-1-oxosulfolane, 1-ethyl-1-oxosulfolane, 1-phenyl-1-oxosulfolane, and the like. Examples thereof include 1-methyl-1-oxophosphorane, 1-n-propyl-1-oxophosphorane, 1-phenyl-1-oxophosphorane and the like. These various aprotic polar organic compounds are each used alone or in combination of two or more, and further mixed with other solvent components which do not disturb the object of the present invention, and the aprotic organic compound is mixed. Can be used as a solvent. Among the above various aprotic organic solvents, preferred are N-alkylcaprolactam and N-alkylpyrrolidone, and particularly preferred is N-alkylpyrrolidone.
Methyl-2-pyrrolidone.

The lithium hydroxide used in the present invention is not particularly limited, and any lithium hydroxide, including commercially available products, can be used as long as it has high purity. The hydrogen sulfide is not particularly limited, and for example, off-gas hydrogen sulfide generated from a petroleum refinery can be used.
Here, the use ratio of hydrogen sulfide to lithium hydroxide (molar ratio: hydrogen sulfide / lithium hydroxide) is usually 1.0 or more, particularly 1.05 or more, from the viewpoint of completion of the reaction. In the present invention, for example, the aprotic organic solvent and lithium hydroxide are charged into a reaction vessel, and then hydrogen sulfide is blown into the obtained charged solution to cause a reaction. In this case, the reaction may be performed by mixing lithium hydroxide with an aprotic solvent solution in which hydrogen sulfide has been previously blown and dissolved in an aprotic organic solvent.

The pressure for blowing hydrogen sulfide may be normal pressure or pressurization. As the blowing time and blowing speed,
There is no particular limitation. The method for blowing hydrogen sulfide is also not particularly limited, and a commonly used method such as bubbling gaseous hydrogen sulfide into N-methyl-2-pyrrolidone while stirring lithium hydroxide therein is used. It can be performed continuously. In this case, water may be present. The reaction temperature is from 0 to 15
0 ° C is preferable, and 120 to 140 ° C is more preferable.
If the temperature is lower than 0 ° C., the reaction rate becomes extremely slow, so that the time required for the synthesis becomes longer and the process becomes uneconomical.
When the temperature exceeds 0 ° C., hydrogen sulfide hardly dissolves in the solution, and as a result, the blow-through amount of hydrogen sulfide increases, and the absorption efficiency deteriorates.

[0011] The reaction time is preferably not less than a value obtained by dividing the required amount of hydrogen sulfide calculated from the use ratio of hydrogen sulfide by the speed at which the supplied hydrogen sulfide does not blow through. If it is less than this, hydrogen sulfide is stoichiometrically insufficient with respect to lithium hydroxide, and the purity of the obtained lithium sulfide is reduced (the raw material lithium hydroxide is mixed in the lithium sulfide). By charging hydrogen sulfide in this manner, lithium hydroxide that has been present in a solid state in the system is dissolved in a liquid portion in the system. After the formation of lithium hydrosulfide as described above, the lithium hydrosulfide (LiS
H) is desulfurized to high purity lithium sulfide (Li ₂
S) is generated.

The reaction temperature at the time of performing this dehydrosulfide reaction is as follows:
150-210 ° C, further 170-210 ° C, especially 190
It is preferably in the range of -210 ° C. If the temperature is lower than 150 ° C., the reaction rate is extremely slow, and the time for dehydrogenation is prolonged, which is uneconomical in the process. If the temperature exceeds 210 ° C., the boiling point of the solvent may be exceeded. Economy. For the reaction time,
0.3 to 7 hours are preferable, and 2 to 7 hours are more preferable. If the reaction time is less than 0.3 hours, the reaction time is insufficient, and lithium hydrosulfide is mixed in the product, and the purity of the lithium sulfide is reduced. If the reaction time is more than 7 hours, the reaction time becomes longer, and the reaction tank becomes larger. It is uneconomical in the connection process. In particular,
When performing a continuous synthesis, it can be performed by using a CSTR (Continuous Stirred Tank Type Reactor) at the above-mentioned temperature and at the above-mentioned time. In addition, it is preferable to dispose a condenser at the upper part of the reaction vessel for the purpose of distilling off water produced as a byproduct during the production of lithium hydrosulfide. This is because the presence of water impedes the progress of the reaction and causes a hydrolysis reaction of the obtained lithium sulfide.

In the present invention, when producing lithium sulfide from the above-mentioned lithium hydrosulfide, the average particle size is 50 μm or less, preferably 30 μm or less, more preferably 20 μm or less.
Although the following fine lithium sulfide particles are produced, the following two methods can be preferably mentioned as a method for producing such fine lithium sulfide particles. (1) A method in which after the production of lithium sulfide, the produced lithium sulfide particles are refined using a wet mill. (2) The rate of temperature increase to the temperature at the time of formation of lithium sulfide is 20
A method of making finer by setting the temperature to at least ° C / hour. In the above method (1), the produced lithium sulfide in the lithium sulfide / aprotic organic solvent slurry is wet-pulverized to be finely divided. Examples of the wet pulverizer that can be used in the present invention include: , A batch or continuous ball mill, a centrifugal crusher, a shear crusher, or the like can be used. The pulverization conditions can be appropriately selected according to the pulverizer used.

In the above method (2), the rate of temperature rise to the predetermined reaction temperature is 20 ° C./hour or more, preferably 3 ° C./hour.
Lithium sulfide generated by setting the temperature to 0 to 120 ° C / hour can be miniaturized. Although the refined lithium sulfide obtained by the above method has the above-mentioned particle size range, the shape of the particles is cubic regardless of the heating rate for the particles produced by the above-described synthesis method. ,
The particles after the wet pulverization are amorphous. The individual particle diameters of the lithium sulfide / aprotic organic solvent slurry are measured by visual measurement using a micrograph or by using a laser type particle size distribution analyzer. The average particle diameter used here is the body area average diameter and is defined below.

[0015]

(Equation 1)

According to such a method, the particle size of the lithium sulfide particles in the slurry can be reduced to 50 μm or less, and more preferably 30 μm or less. In the present invention, PAS is produced using the obtained lithium sulfide. The process includes the above-mentioned lithium sulfide production process, and is roughly divided into the following polymerization step, washing step and separation step. Specifically, in an aprotic organic solvent, a step of polymerizing solid lithium sulfide and a dihalogenated aromatic compound as a polymerization component, a step of washing the polymerization solution with a predetermined washing solution, and a step of washing the polymerization solution and the washing solution Is separated into a polymer phase and a solvent phase as a main step.

Hereinafter, a method for polymerizing PAS in the present invention will be described. The method for producing lithium sulfide is as described above. At this time, the order of adding the raw material components is not particularly limited, but the following three methods can be exemplified. Particularly, the following method is preferable. As the reaction type, any method of a batch type, a continuous type, or a combination of a batch type and a continuous type can be adopted. An aprotic organic solvent solution of lithium hydroxide and a dihalogenated aromatic compound is prepared, and hydrogen sulfide is blown into the aprotic polar organic solvent solution to dissolve the solution. An aprotic solvent solution in which hydrogen sulfide has been previously blown and dissolved is mixed with lithium hydroxide and a dihalogenated aromatic compound. Hydrogen sulfide is blown into and dissolved in a solution of lithium hydroxide in an aprotic organic solvent, and then the dihalogenated aromatic compound is added. The dihalogenated aromatic compound used in the present invention is not particularly limited, but preferred examples include known compounds used for producing polyarylene sulfide.

For example, m-dihalogenbenzene, p-
Dihalogenbenzenes such as dihalogenbenzene; 2,3
-Dihalogentoluene, 2,5-dihalogentoluene,
2,6-dihalogentoluene, 3,4-dihalogentoluene, 2,5-dihalogenxylene, 1-ethyl-2,
Alkyl-substituted dihalogens such as 5-dihalogenbenzene, 1,2,4,5-tetramethyl-3,6-dihalogenbenzene, 1-normalhexyl-2,5-dihalogenbenzene, 1-cyclohexyl-2,5-dihalogenbenzene Benzenes or cycloalkyl-substituted dihalogenbenzenes; 1-phenyl-2,5-dihalogenbenzene, 1-benzyl-2,5-dihalogenbenzene,
Aryl-substituted dihalogenbenzenes such as p-toluyl-2,5-dihalogenbenzene; dihalobiphenyls such as 4,4'-dihalobiphenyl: 1,4-dihalonaphthalene, 1,6-dihalonaphthalene, 2, And dihalonaphthalenes such as 6,6-dihalonaphthalene. The two halogen elements in these dihalogenated aromatic compounds are each fluorine, chlorine, bromine or iodine, and they may be the same or different from each other. Among them, preferred are dihalogenbenzenes, and particularly preferred are those containing 50 mol% or more of p-dichlorobenzene.

The amount of the dihalogen aromatic compound relative to hydrogen sulfide is determined based on the molar ratio of dihalogen aromatic compound / sulfur atom.
0.5 to 2.0, preferably 0.9 to 1.3. When it is less than 0.5, PAS is decomposed, and when it is more than 2.0, the recovery cost of dihalogen aromatic compounds increases. The number of moles of the dihalogen aromatic contained in 1 liter of the aprotic organic solvent is set to 0.8 to 4.0 moles, preferably 1.2 to 3.7 moles. When the amount is less than 0.8 mol / liter, the molecular weight sharply decreases and it is difficult to control the molecular weight. When the amount is 4.0 mol or more, the molecular weight decreases and the physical properties of the resin are not at a practical level. In the case of using a continuous production method, the mixing ratio of each component is the flow ratio (weight, molar amount, etc. per unit time) of each component flowing into a predetermined tank (the same applies to the following description). .

In the present invention, if necessary, an active hydrogen-containing halogenated aromatic compound, a polyhalogenated aromatic compound having three or more halogen atoms in one molecule, in addition to the dihalogenated aromatic compound, and A branching agent such as a polyhalogenated aromatic nitro compound may be appropriately selected, added to the reaction system, and used. The proportion of the branching agent used as needed is usually 0.0005 to 0.05 mol, preferably 0.001 to 0.02 mol, per 1 mol of the hydrogen sulfide. In the present invention, it is preferable to carry out preliminary polymerization of lithium sulfide and a dihalogenated aromatic compound in an aprotic organic solvent, if necessary, in order to produce a PAS having a higher molecular weight. The prepolymerization is not particularly limited.For example, a dihalogenated aromatic compound, water, and an aprotic organic solvent are added to the reaction mixture containing the obtained lithium sulfide compound, and the mixture is batchwise or continuously. 180
It is kept at 250 ° C. for 0.1 to 10 hours, preferably 1 to 6 hours. The amount of each polymerization component preferably satisfies the following conditions.

The number of moles of the dihalogenated aromatic compound contained in one liter of the aprotic organic solvent is from 0.8 to 0.8.
It is preferably 4.0 (mol / liter), more preferably 1.2 to 3.7 (mol / liter). The use ratio of the dihalogenated aromatic compound to 1 mol of hydrogen sulfide is preferably 0.5 to 2 mol, and more preferably 0.5 to 2 mol.
9 to 1.3 mol. The weight ratio of water to the aprotic organic solvent (water / aprotic organic solvent) is preferably 3/97 or more, more preferably 5/95 to 1/95.
5/85. The following continuous main polymerization operation is performed on the polymerization raw material or the produced low molecular weight PAS. The polymerization operation in the present invention is not particularly limited.
It can be carried out in accordance with the conditions disclosed in several known documents such as 8077. Examples of the reaction container include a stainless steel autoclave. The residence time of the polymerization raw material or the low molecular weight PAS flowing into the continuous main polymerization tank in the tank varies depending on the inflow of each component and the shape and size of the tank, but is 0.1 to 20 hours, preferably 0.1 to 20 hours. 1 to 10 hours, more preferably 0.1 to
Adjust for 5 hours.

Although the polymerization operation is described as a single-stage or two-stage polymerization, it may be a multi-stage polymerization of three or more stages, or the temperature condition may be changed to two or more stages. . In the present invention, after the completion of the polymerization operation, if necessary, an alkali metal hydroxide or an alkaline earth metal hydroxide may be added to recover lithium ions. The alkaline earth metal hydroxide or alkaline earth metal hydroxide to be charged after the removal of the PAS from the polymerization solution is not particularly limited, and examples thereof include sodium hydroxide, potassium hydroxide, and magnesium hydroxide. Can be mentioned. Water can be added to the polymerization solution after the main polymerization to such an extent that the PAS does not solidify, and a washing operation can be performed. The amount of water varies depending on the amount and temperature of the polymerization solution, but may be any amount that does not solidify or precipitate PAS due to excessive cooling. It is preferable that the washing tank is usually stirred so that the polymerization solution and water are mixed well.

The washing solution is not particularly limited as long as impurities and by-products adhering to the polymer dissolve therein and do not adversely affect the polymer. For example, methanol, acetone, benzene, toluene, water , NMP. Among them, water is preferred. With respect to the polymerization solution after the completion of the polymerization reaction, a separation operation is performed in a separation tank to separate into a polymer phase and a solvent phase. The method of recovering lithium hydroxide from the separated solvent phase (NMP, water, and LiCl are the main components) can be the same as the above-described operation of recovering lithium ions. The recovered lithium hydroxide can be reused in the charging operation. In addition,
The washing and separating steps may be repeated any number of times in order to obtain more sufficient washing and separating effects.

In the present invention, since the solvent is still contained in the polymer phase after the washing and separation steps, it is preferable to remove the solvent. The solvent removing operation is not particularly limited, and can be based on a solvent removing method used in a known PAS manufacturing method (for example, a flash method disclosed in JP-A-7-33878). The PAS having been subjected to the solvent removal operation can be taken out in a molten state or solidified by cooling by an appropriate method. Examples of the cooling method include air cooling, water cooling, and oil cooling. In the method of the present invention, as described above, the solution viscosity (η _inh ) of the polymer is set to 0.
A polyarylene sulfide of sufficient molecular weight and, in some cases, gel-forming, having a melt index (MI) of at least 10 and preferably at least 0.17 and a melt index (MI) of 0 to 1000 g / 10 min. Can be easily and stably obtained in a simplified process. In addition, η _inh variation with time or between batches during polymer production is significantly improved.

The solution viscosity is such that granular polyarylene sulfide is added to α-chloronaphthalene at 0.4 dl /
g, and measured using a Ubbelohde viscometer at a temperature of 206 ° C. When molding various products from the polyarylene sulfide obtained according to the present invention, if necessary, other polymers, pigments, graphite, metal powder, glass powder, quartz powder, talc, calcium carbonate may be added to the polyarylene sulfide. , Glass fiber,
Fillers such as carbon fibers and various whiskers, stabilizers, release agents and the like can be appropriately compounded. Polyarylene sulfide obtained by the present invention is a material for various molded articles,
For example, it can be suitably used as a material for films, fibers, mechanical parts, electric parts, electronic parts and the like.

[0026]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto. Example 1 A PAS production apparatus equipped with a lithium hydrogen sulfide synthesis tank, a lithium sulfide synthesis tank, a prepolymerization tank (two), a polymerization tank, a washing tank, a separation tank, and a solvent removal tank was used. Each of these seven tanks had the same shape. The inside diameter of the tank was 350 mm, the height of the tank was 300 mm, and the volume was about 30 liters.
Of these tanks, the lithium sulfide synthesis tank is of a batch type,
Other tanks performed a series of manufacturing processes in a continuous manner. Raw Material Synthesis Step (Charging Operation) In a lithium hydrogen sulfide synthesis tank at 100 ° C. and normal pressure, 10.3 kg / h of N-methyl-2-pyrrolidone (NMP), 1.1 kg / h of lithium hydroxide, 1.6 kg of hydrogen sulfide / H continuously for 24 hours. The residence time was 0.4 hours. 25 kg of a synthetic solution containing lithium hydrosulfide at 100 ° C. is stored in a lithium sulfide synthesizing tank.
The temperature was raised from 00 ° C to 180 to 205 ° C at a rate of 10 ° C / hour, and maintained at this temperature for 1 to 5 hours to obtain a slurry containing lithium sulfide.

The body area average diameter of the resultant lithium sulfide particles was measured using a laser diffraction scattering type particle size distribution analyzer LMS-30 manufactured by Seishin Enterprise Co., Ltd.
It was 8 μm. Next, the obtained slurry was subjected to batch treatment using a centrifugal crusher (MIC-2, manufactured by Nara Machinery Co., Ltd.) under the following conditions, and the average diameter of the obtained lithium sulfide particles was 15 μm. Milling conditions Slurry temperature: 50 ° C. Stirring rotor rotation speed: 800 rpm Milling time: 1.58 kg / batch × 12 minutes

Polymerization of PPS <Preliminary Polymerization Operation> The synthesis solution containing lithium sulfide (Li ₂ S) synthesized by the above charging operation and paradichlorobenzene were each mixed at a flow rate of 11.5 kg / h and 3.4 kg / hr.
The mixture was allowed to flow into the first prepolymerization tank at 240 ° C. and 0.3 MPa for 0 hour. The residence time was 1.9 hours. In this operation, a low molecular weight PAS was obtained. Sampling and η _inh
Was 0.13. <Main Polymerization Operation> The polymerization solution containing the low molecular weight PAS was flowed at a flow rate of 14.9 kg / h into the second prepolymerization tank at 260 ° C. and 0.6 MPa and then into the main polymerization tank. The residence time in each tank was the same as in the prepolymerization operation. In this operation, a high molecular weight PAS was obtained. After completion of the main polymerization, the polymerization solution contained 250 g of PAS with respect to 1 liter of NMP, and the production amount was 2.5 kg / h.

<Washing Step> The above-mentioned polymerization solution containing PAS having a high molecular weight, water, and NMP were each added to 14.9 kg /
h, 3.4 kg / h, and 10.2 kg / h. The inside of the tank was stirred at 200 rpm, and the residence time of the polymerization solution was 1 hour. <Separation step> Thereafter, the polymerization solution was flowed from the washing tank to the separation tank at the same flow rate as in the washing step. The residence time of the polymerization liquid was the same as in the washing step. A liquid level meter is installed in the washing tank, and while detecting the interface between the NMP phase and the polymer phase, only the polymer phase is 5.5 kg / h from the valve below the separation tank.
It was taken out at a flow rate of r. The solvent phase was taken out of the separation tank from the top of the separation tank at a flow rate of 23 kg / hr. The solvent phase was subjected to a predetermined treatment and collected.

<Post-Treatment Step> Since the polymer phase taken out of the separation tank contains about 50% by weight of NMP, it was allowed to flow into the solvent removal tank to evaporate NMP and a very small amount of water to take out PAS. . As a result, 60k in 24 hours
g / day of PAS could be produced. The η _inh of the obtained PAS at this time was as shown below with time, and the variation was within ± 0.005 with respect to the average value. The yield was 90%.

Example 2 In Example 1, an aquamizer AQ-5 (batch type ball mill) manufactured by Hosokawa Micron Co., Ltd. was used as a pulverizer, and the batch treatment was carried out under the following conditions. PAS was synthesized. Milling conditions Slurry temperature: 25 ° C. Stirring rotor rotation speed: 400 rpm Milling time: 2.5 kg / batch × 12 minutes The average particle size of the obtained lithium sulfide particles is 10 μm, and the η _inh of the obtained PAS is as follows over time. As shown in
The fluctuation was within ± 0.004 with respect to the average value.

Example 3 Example 1 was repeated in the same manner as in Example 1 except that a simple wet-type agitating mill 200φ (continuous ball mill) manufactured by Kurimoto Iron Works Co., Ltd. was used as a pulverizer and continuously processed under the following conditions. PAS was synthesized. Grinding conditions Slurry temperature: 25 ° C. Stirring rotor rotation speed: 558 rpm Grinding treatment speed: 6.8 kg / Hr The average particle size of the obtained lithium sulfide particles is 12 μm, and the η _inh of the obtained PAS is as shown below with time. And
The fluctuation was within ± 0.004 with respect to the average value.

Example 4 In Example 1, as a pulverizer, C manufactured by Organo Corporation was used.
PAS was synthesized in the same manner as in Example 1 except that a batch treatment was performed under the following conditions using LM-0.8S (shear type pulverizer). Milling conditions Slurry temperature: 35 ° C. Stirring rotor rotation speed: 17000 rpm Milling time: 1.5 kg / batch × 3 minutes The average particle size of the obtained lithium sulfide particles is 38 μm, and the η _inh of the obtained PAS is as follows over time. As shown in
The fluctuation was within ± 0.014 with respect to the average value.

Example 5 In Example 1, the PAS was produced in a completely continuous manner with the lithium sulfide synthesis tank also being a continuous one. The conditions for synthesizing lithium hydrosulfide were the same as those in Example 1. Thereafter, a synthesis solution containing lithium hydrosulfide (LiSH) was supplied at a flow rate of 13 kg / h.
It flowed into a lithium sulfide synthesis tank at 205 ° C. and normal pressure.
The residence time in the tank was 3.0 hours. The average particle size of the obtained lithium sulfide was 82 μm. The obtained lithium sulfide / NMP slurry solution was pulverized in the same manner as in Example 1 and polymerized in PAS in the same manner. The average particle size of the obtained lithium sulfide particles was 12 μm, and η _inh of the PAS was as shown below over time, and the variation was within ± 0.005 with respect to the average value.

Example 6 The same procedure as in Example 1 was repeated except that the lithium sulfide / NMP solution was
PAS was synthesized in the same manner except that the temperature was raised at a rate of up to 205 ° C. at 30 ° C./hour and pulverization was not performed. The average particle size of the obtained lithium sulfide particles is 27 μm.
The η _inh of the PAS was as shown below over time, and the variation was within ± 0.006 with respect to the average value.

Comparative Example 1 A PAS was synthesized in the same manner as in Example 1 except that the lithium sulfide in the lithium sulfide / NMP slurry solution was not subjected to the pulverizing treatment. The η _inh of the obtained PAS was as shown below over time, and the variation was within ± 0.08 with respect to the average value.

Comparative Example 2 A PAS was synthesized in the same manner as in Example 5 except that the lithium sulfide in the lithium sulfide / NMP slurry solution was not subjected to the pulverizing treatment. The η _inh of the obtained PAS over time was as shown below, and the variation was within ± 0.07 with respect to the average value.

[0038]

According to the method for producing polyarylene sulfide by reacting lithium sulfide formed by dehydrogenation of lithium hydrosulfide with a dihalogenated aromatic compound, lithium sulfide particles having an average particle diameter of 50 μm or less are used as lithium sulfide. According to the method of the present invention, the fluctuation of the molecular weight of the PAS to be produced can be significantly reduced.

Claims (3)

[Claims] 1. A method for producing polyarylene sulfide by reacting lithium sulfide generated by dehydrogenation of lithium hydrosulfide with a dihalogenated aromatic compound, wherein the lithium sulfide has an average particle diameter of 50 μm or less. A method for producing polyarylene sulfide, comprising using particles. 2. The method according to claim 1, wherein the lithium sulfide particles having an average particle diameter of 50 μm or less are finely divided by using a wet pulverizer. 3. The dehydrosulfide reaction of lithium hydrosulfide,
2. The method according to claim 1, wherein the heating is performed at a temperature raised at a rate of 20 ° C./hour or more.