WO2020009481A1 - Method for preparing polyarylene sulfide - Google Patents

Abstract

The present invention relates to a method for preparing polyarylene sulfide, wherein the equivalent ratio of a dehalogenated aromatic compound to a sulfur compound is used in a predetermined range and both a dehydration reaction and a polymerization process are performed under optimal conditions, so that polyarylene sulfide having equivalent or higher properties compared with existing ones can be prepared with a high yield of polymerization.

Description

Process for preparing polyarylene sulfide

Cross Citation with Related Applications

This application claims the benefit of priority based on Korean Patent Application No. 10-2018-0077236 dated July 3, 2018 and Korean Patent Application No. 10-2019-0079236 dated July 2, 2019. All content disclosed in the literature is included as part of this specification.

The present invention relates to a method for producing a polyarylene sulfide having excellent strength, heat resistance, flame retardancy, and processability in processing a molded article with improved yield.

Polyarylene sulfide (PAS), which is represented by polyphenylene sulfide (PPS), has excellent strength, heat resistance, flame retardancy and processability due to its excellent strength, heat resistance, flame retardancy and processability. It is widely used as a material to replace the same die casting metal. Particularly, in the case of PPS resin, since the fluidity is good, it is advantageous to use it as a compound by kneading with filler or reinforcing agent such as glass fiber.

In general, PAS is prepared by polymerizing a sulfur source and a dihalogenated aromatic compound under polymerization conditions in the presence of an amide compound such as N-methyl pyrrolidone (NMP), and optionally a molecular weight modifier such as an alkali metal salt is further used. do.

In particular, with increasing demand for PAS, yield improvement in manufacturing PAS is required. For example, Japanese Patent No.5623277 includes a step of adding an aromatic compound such as a dihalo aromatic compound and a trihalo aromatic compound to a liquid phase in a polymerization reaction system after a phase separation polymerization process, and cooling the liquid phase. I win a prize in high yield (

) PAS manufacturing method for obtaining PAS is described. As such a method for producing PAS, a method capable of further improving the yield for obtaining PAS has been desired.

Therefore, in the manufacturing method of polyarylene sulfide which polymerizes a sulfur source and a dihalogenated aromatic compound in presence of an amide type compound, the research about the method of manufacturing polyarylene sulfide in high yield is needed.

The present invention uses the equivalent ratio of the dihalogenated aromatic compound to the sulfur compound in a predetermined range, and optimizes the dehydration reaction and the polymerization process conditions to react the polyarylene sulfide showing excellent strength, heat resistance, flame retardancy, and workability. It is intended to provide a process for producing in yields.

According to one embodiment of the invention, the dehydration reaction of the hydrosulfide of the alkali metal and the hydroxide of the alkali metal in a mixed solvent of water and an amide compound in the presence of an organic acid salt of the alkali metal at a temperature of 185 ℃ to 205 ℃ dehydration) to produce a sulfur source comprising a sulfide of an alkali metal and a mixed solvent of water and an amide compound; And

A dihalogenated aromatic compound and an amide compound are added to the reactor containing the said sulfur source, and it superposes | polymerizes at the temperature from 225 degreeC or more to 245 degreeC or less, and then heats up at temperature from 250 degreeC or more to 260 degreeC or less, and superposes | polymerizes. To prepare a polyarylene sulfide;

Including,

Dehydration liquid removed during the dehydration reaction of the first step, 15% to 35% (v / v) of the amide compound based on the total volume,

In the second step of the polymerization reaction, the dihalogenated aromatic compound is provided at a ratio of 1.04 to 1.08 equivalents based on 1 equivalent of the hydrosulfide of the alkali metal, thereby providing a method for producing polyarylene sulfide.

In the present invention, the polyarylene sulfide may be produced in a yield of 85% or more, and may have a melt viscosity of 20 Pa · S to 150 Pa · S.

As described above, according to the present invention, by using the equivalence ratio of the dihalogenated aromatic compound to the sulfur compound in a predetermined range and optimizing and reacting the dehydration reaction and polymerization process conditions, it has excellent strength, heat resistance, flame retardancy, and workability. There is an excellent effect that can be produced in a high yield of polyarylene sulfide.

1 is a simplified view of a process for preparing the polyarylene sulfide of Example 1 according to an embodiment of the present invention.

In the present invention, terms such as first and second are used to describe various components, and the terms are used only for the purpose of distinguishing one component from another component.

Also, the terminology used herein is for the purpose of describing example embodiments only and is not intended to be limiting of the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. As used herein, the terms "comprise", "comprise" or "have" are intended to indicate that there is a feature, number, step, component, or combination thereof, that is, one or more other features, It should be understood that it does not exclude in advance the possibility of the presence or addition of numbers, steps, components, or combinations thereof.

As the invention allows for various changes and numerous modifications, particular embodiments will be illustrated and described in detail below. However, this is not intended to limit the present invention to the specific disclosed form, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

Hereinafter, the present invention will be described in more detail.

According to one embodiment of the invention, the dehydration for producing a sulfur source is carried out in the presence of an organic acid salt of an alkali metal, and at the same time the equivalent ratio of the dihalogenated aromatic compound to the sulfur compound is used in a predetermined range. By carrying out all polymerization processes under optimum conditions, a method for producing polyarylene sulfide having excellent strength, heat resistance, flame retardancy, processability and the like in high yield is provided.

The method for producing the polyarylene sulfide is a dehydration reaction of an alkali metal hydrosulfide and an alkali metal hydroxide at a temperature of from 185 ° C to 205 ° C in a mixed solvent of water and an amide compound in the presence of an organic acid salt of an alkali metal. performing a dehydration to produce a sulfur source comprising a sulfide of an alkali metal and a mixed solvent of water and an amide compound; And adding a dihalogenated aromatic compound and an amide compound to a reactor including the sulfur source, polymerizing the reaction at a temperature of 225 ° C. or higher to 245 ° C. or lower, and then raising the temperature to 250 ° C. or higher to 260 ° C. or lower to polymerize. Reacting to prepare a polyarylene sulfide;

In addition, the present invention, the dehydration liquid is removed during the dehydration (dehydration) using an alkali metal hydrosulfide, etc. to prepare a polyarylene sulfide, about 15% ( v / v) to about 35% (v / v), wherein the dihalogenated aromatic compound is reacted with an alkali metal in a polymerization reaction in which the sulfur source prepared through the dehydration is reacted with the dihalogenated aromatic compound. And about 1.04 equivalents or more and about 1.08 equivalents or less based on 1 equivalent of hydrosulfide.

In particular, the present invention can significantly increase the yield of the resulting polyarylene sulfide by adding the dihalogenated aromatic compound in a predetermined content range and simultaneously performing the dehydration process and the polymerization process under optimized conditions. In addition, it is possible to easily prepare a polyarylene sulfide showing the thermal properties of the final polymer product is equal or more than the conventional. In addition, the production method of the polyarylene sulfide of the present invention is also improved in yield, it is possible to increase the output of the final product.

Moreover, in the prior art, when preparing a polyarylene sulfide resin having a general viscosity, which is generally used for a non-special purpose, it was not shown exactly what factors affect the yield improvement, but the present inventors have largely influenced the yield among various process factors. Major factors influencing were identified through response surface analysis and the present invention was completed. In particular, according to the present invention, it is possible to produce a general viscosity polyarylene sulfide in an excellent yield by closely checking how the interaction between the reaction effective factors affects each other, thereby obtaining an excellent effect of improving economic efficiency.

First, in the method for producing the polyarylene sulfide according to one embodiment of the present invention, each step will be described.

The first step described above is to prepare a sulfur source.

The sulfur source is prepared by dehydration of an alkali metal hydrosulfide and an alkali metal hydroxide in a mixed solvent of water and an amide compound in the presence of an organic acid salt of the alkali metal. Thus, the sulfur source may include a mixed solvent of water and an amide compound remaining after the dehydration reaction together with the sulfide of the alkali metal produced by the reaction of an alkali metal hydrosulfide with an alkali metal hydroxide.

Subsequently, in the present invention, polyarylene sulfide having excellent yield is prepared through polymerization using the sulfur source, the dihalogenated aromatic compound, and the amide compound.

The sulfide of the alkali metal may be determined according to the type of hydrosulfide of the alkali metal used in the reaction, and specific examples thereof include lithium sulfide, sodium sulfide, potassium sulfide, rubidium sulfide, or cesium sulfide, and any one of these Mixtures of two or more may be included.

In preparing the sulfur source by the reaction of the alkali metal hydroxide with the hydroxide of the alkali metal, specific examples of the alkali metal hydrosulfide that may be used include lithium sulfide, sodium hydrogen sulfide, potassium hydrogen sulfide, rubidium hydrogen sulfide or cesium hydrogen sulfide. have. Any one or a mixture of two or more of these may be used, and anhydrides or hydrates thereof may also be used.

In addition, specific examples of the hydroxide of the alkali metal include lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide, and the like, and any one or a mixture of two or more thereof may be used. The alkali metal hydroxide may be used in an equivalent ratio of about 0.90 to about 2.0, more specifically about 1.0 to about 1.5, and more specifically about 1.0 to about 1.1, based on 1 equivalent of the alkali metal hydrosulfide. have.

In the present invention, the equivalent weight means a molar equivalent weight (eq / mol).

In addition, in the production of a sulfur source by the reaction of the alkali metal hydrosulfide with the alkali metal hydroxide, an organic acid salt of an alkali metal is added, which promotes a polymerization reaction as a polymerization aid to increase the degree of polymerization of polyarylene sulfide in a short time. do. Specifically, the organic acid salt of the alkali metal may be lithium acetate, sodium acetate, or the like, and any one or a mixture of two or more thereof may be used. In addition, the organic acid salt of the alkali metal is generally about 0.01 or more, or about 0.05 or more, or about 0.1 or more, to 1 equivalent of the hydrosulfide of the alkali metal in terms of producing a high yield of melt viscosity suitable for use in general. Or in an equivalent ratio of at least about 0.18, or at least about 0.23. However, in view of the fact that the organic acid salt of the alkali metal is a factor of increase in manufacturing cost when used in an excessive amount in terms of a polymerization aid acting as a catalyst, preferably about 1.0 or less, or about 0.8 or less, or about 0.6 or less, or about 0.5 or less Or equivalent ratios of about 0.45 or less.

The reaction of the alkali metal hydrosulfide and the alkali metal hydroxide may be carried out in a mixed solvent of water and an amide compound, wherein specific examples of the amide compound are N, N-dimethylformamide or N, N Amide compounds such as dimethylacetamide; Pyrrolidone compounds such as N-methyl-2-pyrrolidone (NMP) or N-cyclohexyl-2-pyrrolidone; Caprolactam compounds such as N-methyl-ε-caprolactam; Imidazolidinone compounds, such as 1,3-dialkyl-2-imidazolidinone; Urea compounds such as tetramethyl urea; Or phosphate amide compounds such as hexamethyl phosphate triamide, and the like, and any one or a mixture of two or more thereof may be used. Among these, the amide compound may be more specifically N-methyl-2-pyrrolidone (NMP) in consideration of the reaction efficiency and the effect of the cosolvent as a polymerization solvent in the polymerization for preparing polyarylene sulfide.

In addition, the water may be used in an equivalent ratio of about 1 to about 8 equivalents to 1 equivalent of the amide compound, more specifically in an equivalent ratio of about 1.5 to about 5, and more specifically in an equivalent ratio of about 2.5 to about 4.5 Can be.

Meanwhile, in the first step, a reactant including an alkali metal hydrosulfide, an alkali metal hydroxide, and the like may generate sulfides of the alkali metal through dehydration. At this time, the dehydration reaction is carried out at a temperature range of about 185 ℃ to about 205 ℃, can be carried out by stirring at a speed of about 100 rpm to 500 rpm, more specifically at a speed of about 100 rpm to about 300 rpm have. The dehydration reaction temperature is about 185 ° C. or more in order to lower the amount of water dehydrated and remaining below about 3.5 molar equivalents to 1 mole of effective sulfur in terms of optimizing the amount of effective sulfur contained in the sulfur source used in the subsequent polymerization process. Should be performed. In addition, in order to optimize the content of the amide compound exiting through the dehydration reaction and to ensure that the amount of water remaining in the sulfur source is about 1.5 molar equivalents to 1 mole of effective sulfur, the dehydration reaction temperature is about 205 It should be carried out below ℃.

During this dehydration process, solvents such as water in the reactants may be removed by distillation, etc., and a part of the amide compound is discharged together with the water, and some sulfur contained in the sulfur source reacts with the water by heat during the dehydration process. It may be volatilized as hydrogen sulfide gas. In addition, the hydroxide of the alkali metal of the same mole as the hydrogen sulfide may be produced.

In particular, the total volume of the entire mixture including the mixed solvent of water and the amide compound in the dehydration liquid generated during the dehydration reaction in the first step, i. Based on the amide compound is included from about 15% to about 35% (v / v). In order to optimize the melt viscosity of the polyarylene sulfide finally obtained by reacting a sulfur source prepared through dehydration using the alkali metal hydrosulfide and the like, and a dihalogenated aromatic compound, to prepare in high yield, The concentration of the amide compound should be maintained in the above-described range. Specifically, the concentration of the amide compound in the dehydration solution may be about 25% to about 35% (v / v), or about 28% to about 32% (v / v).

On the other hand, as a result of the reaction of the above-mentioned sulfides of alkali metals, hydroxides of alkali metals and alkali metal salts, sulfides of alkali metals precipitate in a solid phase in a mixed solvent of water and an amide compound, and in the reaction system, Some hydrosulfide may remain. Accordingly, when the sulfur source prepared by reacting the above-mentioned sulfide of alkali metal and hydroxide of alkali metal is used as a sulfur source in the preparation of polyarylene sulfide according to the present invention, the molar ratio of the sulfur source is the alkali precipitated as a result of the reaction. The total molar ratio of sulfide of the metal and unreacted alkali metal hydrosulfide.

Further, during the dehydration process, sulfur contained in the sulfur source remaining in the sulfur source, that is, sulfur sulfide of the alkali metal introduced into the sulfur-containing reactant, and the like reacts with water to produce hydrogen sulfide and alkali metal hydroxide, and the produced hydrogen sulfide Since is volatilized, the amount of sulfur in the sulfur source remaining in the system after the dehydration process may be reduced by the hydrogen sulfide volatilized out of the system during the dehydration process. For example, in the case of using a sulfur source containing alkali metal hydrosulfide as a main component, the amount of sulfur remaining in the system after the dehydration process is a molar amount of sulfur contained in a sulfur source introduced as a reactant, that is, a sulfur-containing reactant of an alkali metal. The amount is equal to minus the molar amount of hydrogen sulfide volatilized out of the system. Accordingly, it is necessary to quantify the amount of effective sulfur contained in the sulfur source remaining in the system after the dehydration process from the amount of hydrogen sulfide volatilized out of the system. Specifically, the water remaining in the system after the dehydration process is completed has a molar ratio of about 1.5 to about 3.5, more specifically about 1.6 to about 3.0, even more specifically about 1.8 to about 2.8 per mole of effective sulfur. May be performed until If the amount of water in the sulfur source is excessively reduced by the dehydration process, water may be adjusted by adding water prior to the polymerization process.

Accordingly, the sulfur source prepared by the reaction and dehydration of the alkali metal hydrosulfide and the alkali metal hydroxide and dehydration may include a mixed solvent of water and an amide compound together with the sulfide of the alkali metal, The water may be included in a molar ratio of about 1.5 to about 3.5 specifically with respect to 1 mole of sulfur contained in the sulfur source. In addition, the sulfur source may further comprise a hydroxide of an alkali metal produced by the reaction of sulfur and water.

Meanwhile, according to one embodiment of the present invention, the second step is a step of polymerizing the sulfur source with a dihalogenated aromatic compound to prepare polyarylene sulfide.

The dihalogenated aromatic compound usable for the preparation of the polyarylene sulfide is a compound in which two hydrogens in an aromatic ring are substituted with halogen atoms, and specific examples thereof include o-dihalobenzene, m-dihalobenzene, and p-dihal. Robenzene, dihalotoluene, dihalonaphthalene, dihalobiphenyl, dihalobenzoic acid, dihalodiphenylether, dihalodiphenylsulfone, dihalodiphenylsulfoxide or dihalodiphenyl ketone, and the like. Mixtures of two or more may be used. In the dihalogenated aromatic compound, the halogen atom may be fluorine, chlorine, bromine or iodine. Among them, p-dichlorobenzene (p-DCB) may be used in consideration of the effect of reducing the reactivity and side reaction generation in the production of polyarylene sulfide.

The dihalogenated aromatic compound should be added at about 1.04 to about 1.08 equivalents based on 1 equivalent of the hydrosulfide of the alkali metal. When introduced in the above content range, it is possible to prepare a polyarylene sulfide having excellent physical properties without concern for the increase in the chlorine content present in the polyarylene sulfide to be produced. The dihalogenated aromatic compound is about 1.04 to about 1.08 in order to take into account the superiority of the improvement effect by controlling the addition amount of the sulfur source and the dihalogenated aromatic compound, to control the melt viscosity and the total volatile organic compound, and to improve the yield. It should be put in equivalence.

Further, before proceeding to the second step, the method may further include lowering the temperature of the reactor including the sulfur source to a temperature of less than about 200 ° C. to less than about 200 ° C. to prevent vaporization of the dihalogenated aromatic compound. have.

In addition, the polymerization of the sulfur source and the dihalogenated aromatic compound may be carried out in a solvent of an amide compound which is stable to alkali at high temperature as an aprotic polar organic solvent.

Specific examples of the amide compound are as described above, and considering the reaction efficiency among the illustrated compounds, more specifically, the amide compound may be N-methyl-2-pyrrolidone (NMP).

Since the amide compound contained in the sulfur source in the first step may act as a co-solvent, the amide compound added in the second step is a molar ratio of water (H ₂ O) to the amide compound present in the polymerization system. (Molar ratio of water / amide compound) can be added in an amount such that it is about 0.85 or more.

In particular, the amide-based compound further added in the second step is about 1.0 equivalent to about 2.0 equivalents, or about 1.1 equivalents to about 1.85 equivalents, or about 1.1 equivalents to about 1.35, based on 1 equivalent of the hydrosulfide of the alkali metal. It can be added in equivalent weight. Here, when performing the polymerization reaction in the second step, the amide compound is added to the molar ratio of 2.5 to 4.0 with respect to 1 mol of sulfur. This corresponds to the content of the final amide compound present in the system during the second stage of the polymerization reaction, and is further added in the second stage and the remaining amide compound in the sulfur source obtained through the dehydration reaction in the first stage. It can be said that it is the total amount of an amide compound. On the other hand, the final content of the amide compound present in the system during the polymerization step of the second step, for example, from the total amount of the amide compound introduced in each of the first step and the second step proceeds to the dehydration solution of the first step It can confirm by subtracting the quantity of the outgoing amide compound, and acidifying.

In addition, other additives for controlling the polymerization reaction or molecular weight, such as a molecular weight adjusting agent, a crosslinking agent during the polymerization reaction may be further added in a content that does not lower the physical properties and production yield of the polyarylene sulfide to be finally prepared.

On the other hand, in the second step of the polymerization step of producing a polyarylene sulfide by polymerizing the sulfur source of the present invention with a dihalogenated aromatic compound, a prepolymer of polyarylene sulfide is reacted by reacting a halogenated aromatic compound with a sulfur compound. It is characterized in that it is carried out in a multi-step, including a shear polymerization process for producing a polymer) and a post-stage polymerization process for increasing the molecular weight and melt viscosity by using the prepolymer.

Accordingly, in the present invention, the polymerization reaction of the sulfur source and the dihalogenated aromatic compound is specifically a temperature higher than the temperature at the time of the first polymerization reaction continuously after the first polymerization reaction from about 225 ° C. or more to about 245 ° C. or less. Specifically, the secondary polymerization should be carried out from about 250 ° C. or higher to about 260 ° C. or lower. In order to effectively produce the prepolymer, the first polymerization reaction should be carried out in an aromatic compound in a temperature range of about 225 ° C. or more and about 245 ° C. or less in terms of conversion and yield improvement. Or less than or about 230 ° C. or higher and about 245 ° C. or lower. In addition, the secondary polymerization reaction should be carried out at more than 250 ℃ in terms of maintaining the melt viscosity to a sufficient degree to effectively perform the injection molding, and to reduce the yield and melt viscosity decrease due to high temperature decomposition reaction due to excessive temperature rise In terms of prevention, it should be carried out below 260 ℃.

For example, the secondary polymerization may be performed at a temperature higher than about 5 ° C. to about 35 ° C., specifically about 5 ° C. to about 32 ° C., or about 20 ° C. to about 30 ° C. It can be carried out at a high temperature.

The reaction product produced as a result of the polymerization reaction is separated into an aqueous phase and an organic phase, wherein polyarylene sulfide as a polymerization reactant is dissolved in the organic phase. Accordingly, the process for the precipitation and separation of the polyarylene sulfide prepared may be optionally further performed.

Specifically, the precipitation of the polyarylene sulfide may be performed by adding water to the reaction mixture in a ratio of 3 to 5 equivalents to 1 equivalent of sulfur and cooling. When water is added in the above content range, polyarylene sulfide can be precipitated with excellent efficiency.

The precipitated polyarylene sulfide may then optionally be further subjected to washing and filtration drying processes in accordance with conventional methods.

Specific examples of the polyarylene sulfide may be referred to the following examples. However, the manufacturing method of the polyarylene sulfide is not limited to the contents described herein, and the manufacturing method may further employ a step generally employed in the art to which the present invention pertains, Step (s) may be modified by conventionally changeable step (s).

On the other hand, by the method of producing a polyarylene sulfide according to an embodiment of the present invention as described above, it is possible to easily produce a polyarylene sulfide having excellent yields while exhibiting thermal properties equivalent to those of conventional ones.

Specifically, the polyarylene sulfide produced by the above production method is produced in a yield of about 85% or more, or about 85.5% or more, and is about 20 Pa.S to 150 Pa.S, or about 22 Pa.S to 130. Pa.S, or about 25 Pa.S to 120 Pa.S, or about 40 Pa.S to 120 Pa.S. Here, when the melt viscosity of the polyarylene sulfide is too low, the polymer repeating unit is shortened, so that the content of the end group, Cl, etc. is increased, and thus, the mechanical strength may be lowered. desirable. On the other hand, if the melt viscosity of such polyarylene sulfide is too high, the molding conditions may be changed in order to facilitate the molding during injection molding, so about 150 Pa · S or less is preferable. That is, the polyarylene sulfide may be maintained in the above-described range because the melt viscosity is too small, the mechanical strength is insufficient, and when the polyarylene sulfide is too large, the fluidity during melt molding of the resin composition is poor and the molding operation becomes difficult.

In addition, the polyarylene sulfide may have a melting melting temperature (Tm) of about 270 ° C to about 300 ° C, and a crystallization temperature (Tc) of about 180 ° C to 250 ° C. Here, the melting point (Tm) and crystallization temperature (Tc) of the polyarylene sulfide may be measured using a differential scanning calorimeter (DSC) device (TA instrument, TA Q2000), and a measuring method thereof Is well known in the art and a detailed description thereof will be omitted.

On the other hand, the polyarylene sulfide may have a weight average molecular weight (Mw) of more than about 10000 g / mol to about 30000 g / mol or less. Here, the weight average molecular weight (Mw) of the polyarylene sulfide can be measured using gel permeation chromatography (GPC), for example, using a Waters PL-GPC220 instrument as a gel permeation chromatography (GPC) apparatus, Polymer Laboratories PLgel MIX-B can be measured using a 300mm length column, the measuring method is well known in the art and a detailed description thereof will be omitted.

Hereinafter, preferred examples are provided to aid in understanding the present invention. However, the following examples are merely provided to more easily understand the present invention, and the contents of the present invention are not limited thereto.

<Example>

Example 1

In order to make a PPS polymer, a dehydration reaction (first step) and a polymerization reaction (second step) were performed according to the method as shown in FIG. 1.

(1) dehydration reaction

Sodium sulfide (Na ₂ S) was prepared by mixing 1.00 equivalents of sodium hydrogen sulfide (NaSH) and 1.05 equivalents of sodium hydroxide (NaOH) in a reactor. At this time, 0.44 equivalents of sodium acetate (CH ₃ COONa) powder, 1.65 equivalents of N-methyl-2-pyrrolidone (NMP) and 4.72 equivalents of distilled water were added to the reactor. The reactor was heated to 195 ° C. for 1 hour with stirring at 150 rpm to carry out a dehydration reaction, and the remaining mixture obtained after the dehydration reaction was obtained as a sulfur source. At this time, the measured NMP concentration (v / v%) in the dehydration liquid that was removed to the outside while performing the dehydration reaction was 30.2% as measured by gas chromatography. In addition, the molar ratio of H ₂ O / S in the remaining mixture obtained as the sulfur source was calculated to be 1.82.

(2) polymerization reaction

After the temperature of the reactor including the sulfur source obtained through the dehydration reaction was lowered to below 170 ° C., 1.04 equivalents of para-dichlorobenzene (p-DCB) and 1.35 equivalents of NMP were added to the reactor. At this time, the molar ratio of NMP / S was calculated to be 2.63. And the obtained mixed solution was heated to 230 degreeC and made to react for 2 hours, and also it heated up to 260 degreeC and made to react for further 2 hours. After the reaction was completed, 3 equivalents of distilled water was added into the reactor with respect to 1 equivalent of sulfur present in the reactor, and the resultant was recovered after sufficiently lowering the temperature. The resultant was washed sequentially with a mixture of distilled water and NMP (mixed volume ratio = 1: 1) and distilled water, followed by filtration, washed with NMP for 10 minutes at 90 ° C., and filtered, and then, 90% with an aqueous 0.4% acetic acid solution. After washing at ℃ and filtered, and again filtered at 90 ℃ for 10 minutes with distilled water. The washed polyphenylene sulfide was recovered by drying in a vacuum oven at 150 ° C. for 8 hours.

The yield of polyphenylene sulfide recovered at this time was 85.8%, and the viscosity was 73.8 Pa · S.

Example 2

In order to make a PPS polymer, a dehydration reaction (first step) and a polymerization reaction (second step) were performed according to the method as shown in FIG. 1.

(1) dehydration reaction

Sodium sulfide (Na2S) was prepared by mixing 1.00 equivalents of sodium hydrogen sulfide (NaSH) and 1.05 equivalents of sodium hydroxide (NaOH) in a reactor. At this time, 0.44 equivalents of sodium acetate (CH ₃ COONa) powder, 1.65 equivalents of N-methyl-2-pyrrolidone (NMP) and 4.72 equivalents of distilled water were added to the reactor. The reactor was heated to 205 ° C. for 1 hour with stirring at 150 rpm to carry out a dehydration reaction, and the remaining mixture obtained after the dehydration reaction was obtained as a sulfur source. At this time, the measured NMP concentration (v / v%) in the dehydration liquid which was removed to the outside while performing the dehydration reaction was 30.6% as measured by gas chromatography. In addition, the molar ratio of H ₂ O / S in the remaining mixture obtained as the sulfur source was calculated to be 1.85.

(2) polymerization reaction

After the temperature of the reactor including the sulfur source obtained through the dehydration reaction was lowered below 170 ° C., 1.06 equivalents of para-dichlorobenzene (p-DCB) and 1.35 equivalents of NMP were added to the reactor. At this time, the molar ratio of NMP / S was calculated to be 2.62. And the obtained mixed solution was heated to 230 degreeC and made to react for 2 hours, and it heated up again to 250 degreeC and made it react for 2 hours further. After the reaction was completed, 3 equivalents of distilled water was added into the reactor with respect to 1 equivalent of sulfur present in the reactor, and the resultant was recovered after sufficiently lowering the temperature. The resultant was washed sequentially with a mixture of distilled water and NMP (mixed volume ratio = 1: 1) and distilled water, followed by filtration, washed with NMP for 10 minutes at 90 ° C., and filtered, and then, 90% with an aqueous 0.4% acetic acid solution. After washing at ℃ and filtered, and again filtered at 90 ℃ for 10 minutes with distilled water. The washed polyphenylene sulfide was recovered by drying in a vacuum oven at 150 ° C. for 8 hours.

The yield of polyphenylene sulfide recovered at this time was 86.4%, and the viscosity was 58.0 Pa · S.

Example 3

In order to make a PPS polymer, a dehydration reaction (first step) and a polymerization reaction (second step) were performed according to the method as shown in FIG. 1.

(1) dehydration reaction

Sodium sulfide (Na2S) was prepared by mixing 1.00 equivalents of sodium hydrogen sulfide (NaSH) and 1.05 equivalents of sodium hydroxide (NaOH) in a reactor. At this time, 0.44 equivalents of sodium acetate (CH ₃ COONa) powder, 1.65 equivalents of N-methyl-2-pyrrolidone (NMP) and 4.72 equivalents of distilled water were added to the reactor. The reactor was heated to 205 ° C. for 1 hour with stirring at 150 rpm to carry out a dehydration reaction, and the remaining mixture obtained after the dehydration reaction was obtained as a sulfur source. At this time, the measured NMP concentration (v / v%) in the dehydration liquid that was removed to the outside while performing the dehydration reaction was 30.9% as measured by gas chromatography. In addition, the molar ratio of H ₂ O / S in the remaining mixture obtained as the sulfur source was calculated to be 1.81.

(2) polymerization reaction

After the temperature of the reactor including the sulfur source obtained through the dehydration reaction was lowered to below 170 ° C., 1.04 equivalents of para-dichlorobenzene (p-DCB) and 1.35 equivalents of NMP were added to the reactor. At this time, the molar ratio of NMP / S was calculated to be 2.61. And the obtained mixed solution was heated to 230 degreeC and made to react for 2 hours, and also it heated up to 255 degreeC and made to react for further 2 hours. After the reaction was completed, 3 equivalents of distilled water was added into the reactor with respect to 1 equivalent of sulfur present in the reactor, and the resultant was recovered after sufficiently lowering the temperature. The resultant was washed sequentially with a mixture of distilled water and NMP (mixed volume ratio = 1: 1) and distilled water, followed by filtration, washed with NMP for 10 minutes at 90 ° C., and filtered, and then, 90% with an aqueous 0.4% acetic acid solution. After washing at ℃ and filtered, and again filtered at 90 ℃ for 10 minutes with distilled water. The washed polyphenylene sulfide was recovered by drying in a vacuum oven at 150 ° C. for 8 hours.

The yield of polyphenylene sulfide recovered at this time was 85.0%, and the viscosity was 65.1 Pa.S.

Example 4

In order to make a PPS polymer, a dehydration reaction (first step) and a polymerization reaction (second step) were performed according to the method as shown in FIG. 1.

(1) dehydration reaction

Sodium sulfide (Na2S) was prepared by mixing 1.00 equivalents of sodium hydrogen sulfide (NaSH) and 1.05 equivalents of sodium hydroxide (NaOH) in a reactor. At this time, 0.44 equivalents of sodium acetate (CH ₃ COONa) powder, 1.65 equivalents of N-methyl-2-pyrrolidone (NMP) and 4.72 equivalents of distilled water were added to the reactor. The reactor was heated to 185 ° C. for 1 hour with stirring at 150 rpm to carry out a dehydration reaction, and the remaining mixture obtained after the dehydration reaction was obtained as a sulfur source. At this time, the measured NMP concentration (v / v%) in the dehydration liquid that was removed to the outside while performing the dehydration reaction was 31.0% as measured by gas chromatography. In addition, the molar ratio of H ₂ O / S in the remaining mixture obtained as the sulfur source was calculated to be 2.30.

(2) polymerization reaction

After the temperature of the reactor including the sulfur source obtained through the dehydration reaction was lowered below 170 ° C., 1.06 equivalents of para-dichlorobenzene (p-DCB) and 1.35 equivalents of NMP were added to the reactor. At this time, the molar ratio of NMP / S was calculated to be 2.65. And the obtained mixed solution was heated to 230 degreeC and made to react for 2 hours, and also it heated up to 260 degreeC and made to react for further 2 hours. After the reaction was completed, 3 equivalents of distilled water was added into the reactor with respect to 1 equivalent of sulfur present in the reactor, and the resultant was recovered after sufficiently lowering the temperature. The resultant was washed sequentially with a mixture of distilled water and NMP (mixed volume ratio = 1: 1) and distilled water, followed by filtration, washed with NMP for 10 minutes at 90 ° C., and filtered, and then, 90% with an aqueous 0.4% acetic acid solution. After washing at ℃ and filtered, and again filtered at 90 ℃ for 10 minutes with distilled water. The washed polyphenylene sulfide was recovered by drying in a vacuum oven at 150 ° C. for 8 hours.

The yield of polyphenylene sulfide recovered at this time was 91.6%, and the viscosity was 46.4 Pa · S.

Example 5

In order to make a PPS polymer, a dehydration reaction (first step) and a polymerization reaction (second step) were performed according to the method as shown in FIG. 1.

(1) dehydration reaction

Sodium sulfide (Na2S) was prepared by mixing 1.00 equivalents of sodium hydrogen sulfide (NaSH) and 1.05 equivalents of sodium hydroxide (NaOH) in a reactor. At this time, 0.44 equivalents of sodium acetate (CH ₃ COONa) powder, 1.65 equivalents of N-methyl-2-pyrrolidone (NMP) and 4.72 equivalents of distilled water were added to the reactor. The reactor was heated to 195 ° C. for 1 hour with stirring at 150 rpm to carry out a dehydration reaction, and the remaining mixture obtained after the dehydration reaction was obtained as a sulfur source. At this time, the NMP concentration (v / v%) measured in the dehydration liquid which was removed to the outside while performing the dehydration reaction was 29.9% as measured by gas chromatography. In addition, the molar ratio of H ₂ O / S in the remaining mixture obtained as the sulfur source was calculated to be 1.92.

(2) polymerization reaction

After lowering the temperature of the reactor including the sulfur source obtained through the dehydration reaction to less than 170 ℃, 1.08 equivalents of para-dichlorobenzene (p-DCB) and 1.35 equivalents of NMP were added to the reactor. At this time, the molar ratio of NMP / S was calculated to be 2.64. And the obtained mixed solution was heated to 230 degreeC and made to react for 2 hours, and it heated up again to 250 degreeC and made it react for 2 hours further. After the reaction was completed, 3 equivalents of distilled water was added into the reactor with respect to 1 equivalent of sulfur present in the reactor, and the resultant was recovered after sufficiently lowering the temperature. The resultant was washed sequentially with a mixture of distilled water and NMP (mixed volume ratio = 1: 1) and distilled water, followed by filtration, washed with NMP for 10 minutes at 90 ° C., and filtered, and then, 90% with an aqueous 0.4% acetic acid solution. After washing at ℃ and filtered, and again filtered at 90 ℃ for 10 minutes with distilled water. The washed polyphenylene sulfide was recovered by drying in a vacuum oven at 150 ° C. for 8 hours.

The yield of polyphenylene sulfide recovered at this time was 87.8%, and the viscosity was 27.3 Pa · S.

Comparative Example 1

In order to make a PPS polymer, a dehydration reaction (first step) and a polymerization reaction (second step) were performed according to the method as shown in FIG. 1.

(1) dehydration reaction

Sodium sulfide (Na ₂ S) was prepared by mixing 1.00 equivalents of sodium hydrogen sulfide (NaSH) and 1.05 equivalents of sodium hydroxide (NaOH) in a reactor. At this time, 0.44 equivalents of sodium acetate (CH ₃ COONa) powder, 1.65 equivalents of N-methyl-2-pyrrolidone (NMP) and 4.72 equivalents of distilled water were added to the reactor. The reactor was heated to 185 ° C. for 1 hour with stirring at 150 rpm to carry out a dehydration reaction, and the remaining mixture obtained after the dehydration reaction was obtained as a sulfur source. At this time, the measured NMP concentration (v / v%) in the dehydration liquid that was removed to the outside while performing the dehydration reaction was 29.7% as measured by gas chromatography. In addition, the molar ratio of H ₂ O / S in the remaining mixture obtained as the sulfur source was calculated to be 2.09.

(2) polymerization reaction

After the temperature of the reactor including the sulfur source obtained through the dehydration reaction was lowered below 170 ° C., 1.015 equivalents of para-dichlorobenzene (p-DCB) and 1.35 equivalents of NMP were added to the reactor. At this time, the molar ratio of NMP / S was calculated to be 2.66. And the obtained mixed solution was heated to 230 degreeC and made to react for 2 hours, and it heated up again to 250 degreeC and made it react for 2 hours further. After the reaction was completed, 3 equivalents of distilled water was added into the reactor with respect to 1 equivalent of sulfur present in the reactor, and the resultant was recovered after sufficiently lowering the temperature. The resultant was washed sequentially with a mixture of distilled water and NMP (mixed volume ratio = 1: 1) and distilled water, followed by filtration, washed with NMP for 10 minutes at 90 ° C., and filtered, and then, 90% with an aqueous 0.4% acetic acid solution. After washing at ℃ and filtered, and again filtered at 90 ℃ for 10 minutes with distilled water. The washed polyphenylene sulfide was recovered by drying in a vacuum oven at 150 ° C. for 8 hours.

The yield of polyphenylene sulfide recovered at this time was 79.6%, and the viscosity was 56.4 Pa · S.

Comparative Example 2

In order to make a PPS polymer, a dehydration reaction (first step) and a polymerization reaction (second step) were performed according to the method as shown in FIG. 1.

(1) dehydration reaction

Sodium sulfide (Na ₂ S) was prepared by mixing 1.00 equivalents of sodium hydrogen sulfide (NaSH) and 1.05 equivalents of sodium hydroxide (NaOH) in a reactor. At this time, 0.44 equivalents of sodium acetate (CH ₃ COONa) powder, 1.65 equivalents of N-methyl-2-pyrrolidone (NMP) and 4.72 equivalents of distilled water were added to the reactor. The reactor was heated to 180 ° C. for 1 hour with stirring at 150 rpm to carry out a dehydration reaction, and the remaining mixture obtained after the dehydration reaction was obtained as a sulfur source. At this time, the NMP concentration (v / v%) measured in the dehydration liquid which was removed to the outside while performing the dehydration reaction was 31.2% as measured by gas chromatography. In addition, the molar ratio of H ₂ O / S in the remaining mixture obtained as the sulfur source was calculated to be 2.38.

(2) polymerization reaction

After lowering the temperature of the reactor including the sulfur source obtained through the dehydration reaction to less than 170 ℃, 0.99 equivalents of para-dichlorobenzene (p-DCB) and 1.35 equivalents of NMP were added to the reactor. At this time, the molar ratio of NMP / S was calculated to be 2.63. And the obtained mixed solution was heated to 230 degreeC and made to react for 2 hours, and it heated up again to 250 degreeC and made it react for 2 hours further. After the reaction was completed, 3 equivalents of distilled water was added into the reactor with respect to 1 equivalent of sulfur present in the reactor, and the resultant was recovered after sufficiently lowering the temperature. The resultant was washed sequentially with a mixture of distilled water and NMP (mixed volume ratio = 1: 1) and distilled water, followed by filtration, washed with NMP for 10 minutes at 90 ° C., and filtered, and then, 90% with an aqueous 0.4% acetic acid solution. After washing at ℃ and filtered, and again filtered at 90 ℃ for 10 minutes with distilled water. The washed polyphenylene sulfide was recovered by drying in a vacuum oven at 150 ° C. for 8 hours.

The yield of polyphenylene sulfide recovered at this time was 77.7%, and the viscosity was 61.1 Pa · S.

Comparative Example 3

In order to make a PPS polymer, a dehydration reaction (first step) and a polymerization reaction (second step) were performed according to the method as shown in FIG. 1.

(1) dehydration reaction

Sodium sulfide (Na2S) was prepared by mixing 1.00 equivalents of sodium hydrogen sulfide (NaSH) and 1.05 equivalents of sodium hydroxide (NaOH) in a reactor. At this time, 0.44 equivalents of sodium acetate (CH ₃ COONa) powder, 1.65 equivalents of N-methyl-2-pyrrolidone (NMP) and 4.72 equivalents of distilled water were added to the reactor. The reactor was heated to 180 ° C. for 1 hour with stirring at 150 rpm to carry out a dehydration reaction, and the remaining mixture obtained after the dehydration reaction was obtained as a sulfur source. At this time, the measured NMP concentration (v / v%) in the dehydration liquid that was removed to the outside while performing the dehydration reaction was 30.4% as measured by gas chromatography. In addition, the molar ratio of H ₂ O / S in the remaining mixture obtained as the sulfur source was calculated to be 2.44.

(2) polymerization reaction

After lowering the temperature of the reactor including the sulfur source obtained through the dehydration reaction to less than 170 ℃, 0.99 equivalents of para-dichlorobenzene (p-DCB) and 1.35 equivalents of NMP were added to the reactor. At this time, the molar ratio of NMP / S was calculated to be 2.65. And the obtained mixed solution was heated to 230 degreeC and made to react for 2 hours, and also it heated up to 260 degreeC and made to react for further 2 hours. After the reaction was completed, 3 equivalents of distilled water was added into the reactor with respect to 1 equivalent of sulfur present in the reactor, and the resultant was recovered after sufficiently lowering the temperature. The resultant was washed sequentially with a mixture of distilled water and NMP (mixed volume ratio = 1: 1) and distilled water, followed by filtration, washed with NMP for 10 minutes at 90 ° C., and filtered, and then, 90% with an aqueous 0.4% acetic acid solution. After washing at ℃ and filtered, and again filtered at 90 ℃ for 10 minutes with distilled water. The washed polyphenylene sulfide was recovered by drying in a vacuum oven at 150 ° C. for 8 hours.

The yield of polyphenylene sulfide recovered at this time was 69.4%, and the viscosity was 220.3 Pa · S.

Comparative Example 4

In order to make a PPS polymer, a dehydration reaction (first step) and a polymerization reaction (second step) were performed according to the method as shown in FIG. 1.

(1) dehydration reaction

Sodium sulfide (Na2S) was prepared by mixing 1.00 equivalents of sodium hydrogen sulfide (NaSH) and 1.05 equivalents of sodium hydroxide (NaOH) in a reactor. At this time, 0.44 equivalents of sodium acetate (CH ₃ COONa) powder, 1.65 equivalents of N-methyl-2-pyrrolidone (NMP) and 4.72 equivalents of distilled water were added to the reactor. The reactor was heated to 215 ° C. for 1 hour with stirring at 150 rpm to carry out a dehydration reaction, and the remaining mixture obtained after the dehydration reaction was obtained as a sulfur source. At this time, the measured NMP concentration (v / v%) in the dehydration liquid that was removed to the outside while performing the dehydration reaction was 35.0% as measured by gas chromatography. In addition, the molar ratio of H ₂ O / S in the remaining mixture obtained as the sulfur source was calculated to be 2.13.

(2) polymerization reaction

After the temperature of the reactor including the sulfur source obtained through the dehydration reaction was lowered below 170 ° C., 1.025 equivalents of para-dichlorobenzene (p-DCB) and 1.35 equivalents of NMP were added to the reactor. At this time, the molar ratio of NMP / S was calculated to be 2.55. And the obtained mixed solution was heated to 230 degreeC and made to react for 2 hours, and it heated up again to 250 degreeC and made it react for 2 hours further. After the reaction was completed, 3 equivalents of distilled water was added into the reactor with respect to 1 equivalent of sulfur present in the reactor, and the resultant was recovered after sufficiently lowering the temperature. The resultant was washed sequentially with a mixture of distilled water and NMP (mixed volume ratio = 1: 1) and distilled water, followed by filtration, washed with NMP for 10 minutes at 90 ° C., and filtered, and then, 90% with an aqueous 0.4% acetic acid solution. After washing at ℃ and filtered, and again filtered at 90 ℃ for 10 minutes with distilled water. The washed polyphenylene sulfide was recovered by drying in a vacuum oven at 150 ° C. for 8 hours.

The yield of polyphenylene sulfide recovered at this time was 74.8%, and the viscosity was 62.3 Pa · S.

Comparative Example 5

In order to make a PPS polymer, a dehydration reaction (first step) and a polymerization reaction (second step) were performed according to the method as shown in FIG. 1.

(1) dehydration reaction

Sodium sulfide (Na2S) was prepared by mixing 1.00 equivalents of sodium hydrogen sulfide (NaSH) and 1.05 equivalents of sodium hydroxide (NaOH) in a reactor. At this time, 0.44 equivalents of sodium acetate (CH ₃ COONa) powder, 1.65 equivalents of N-methyl-2-pyrrolidone (NMP) and 4.72 equivalents of distilled water were added to the reactor. The reactor was heated to 185 ° C. for 1 hour with stirring at 150 rpm to carry out a dehydration reaction, and the remaining mixture obtained after the dehydration reaction was obtained as a sulfur source. At this time, the measured NMP concentration (v / v%) in the dehydration liquid that was removed to the outside while performing the dehydration reaction was 28.9% as measured by gas chromatography. In addition, the molar ratio of H ₂ O / S in the remaining mixture obtained as the sulfur source was calculated to be 2.21.

(2) polymerization reaction

After the temperature of the reactor including the sulfur source obtained through the dehydration reaction was lowered below 170 ° C., 1.10 equivalents of para-dichlorobenzene (p-DCB) and 1.35 equivalents of NMP were added to the reactor. At this time, the molar ratio of NMP / S was calculated to be 2.68. And the obtained mixed solution was heated to 230 degreeC and made to react for 2 hours, and it heated up again to 250 degreeC and made it react for 2 hours further. After the reaction was completed, 3 equivalents of distilled water was added into the reactor with respect to 1 equivalent of sulfur present in the reactor, and the resultant was recovered after sufficiently lowering the temperature. The resultant was washed sequentially with a mixture of distilled water and NMP (mixed volume ratio = 1: 1) and distilled water, followed by filtration, washed with NMP for 10 minutes at 90 ° C., and filtered, and then, 90% with an aqueous 0.4% acetic acid solution. After washing at ℃ and filtered, and again filtered at 90 ℃ for 10 minutes with distilled water. The washed polyphenylene sulfide was recovered by drying in a vacuum oven at 150 ° C. for 8 hours.

The yield of polyphenylene sulfide recovered at this time was 83.2%, and the viscosity was 9.8 Pa.S.

Comparative Example 6

In order to make a PPS polymer, a dehydration reaction (first step) and a polymerization reaction (second step) were performed according to the method as shown in FIG. 1.

(1) dehydration reaction

Sodium sulfide (Na2S) was prepared by mixing 1.00 equivalents of sodium hydrogen sulfide (NaSH) and 1.05 equivalents of sodium hydroxide (NaOH) in a reactor. At this time, 0.20 equivalents of sodium acetate (CH ₃ COONa) powder, 1.65 equivalents of N-methyl-2-pyrrolidone (NMP) and 4.72 equivalents of distilled water were added to the reactor. The reactor was heated to 210 ° C. for 1 hour with stirring at 150 rpm to carry out a dehydration reaction, and the remaining mixture obtained after the dehydration reaction was obtained as a sulfur source. At this time, the measured NMP concentration (v / v%) in the dehydration liquid that was removed to the outside while performing the dehydration reaction was 28.6% as measured by gas chromatography. In addition, the molar ratio of H ₂ O / S in the remaining mixture obtained as the sulfur source was calculated to be 1.82.

(2) polymerization reaction

After the temperature of the reactor including the sulfur source obtained through the dehydration reaction was lowered to below 170 ° C., 1.04 equivalents of para-dichlorobenzene (p-DCB) and 1.65 equivalents of NMP were added to the reactor. At this time, the molar ratio of NMP / S was calculated to be 2.96. And the obtained mixed solution was heated to 230 degreeC and made to react for 2 hours, and also it heated to 245 degreeC and made to react for further 2 hours. After the reaction was completed, 3 equivalents of distilled water was added into the reactor with respect to 1 equivalent of sulfur present in the reactor, and the resultant was recovered after sufficiently lowering the temperature. The resultant was washed sequentially with a mixture of distilled water and NMP (mixed volume ratio = 1: 1) and distilled water, followed by filtration, washed with NMP for 10 minutes at 90 ° C., and filtered, and then, 90% with an aqueous 0.4% acetic acid solution. After washing at ℃ and filtered, and again filtered at 90 ℃ for 10 minutes with distilled water. The washed polyphenylene sulfide was recovered by drying in a vacuum oven at 150 ° C. for 8 hours.

The yield of polyphenylene sulfide recovered at this time was 68.0%, and the viscosity was 6.1 Pa.S.

Comparative Example 7

In order to make a PPS polymer, a dehydration reaction (first step) and a polymerization reaction (second step) were performed according to the method as shown in FIG. 1.

(1) dehydration reaction

Sodium sulfide (Na2S) was prepared by mixing 1.00 equivalents of sodium hydrogen sulfide (NaSH) and 1.05 equivalents of sodium hydroxide (NaOH) in a reactor. At this time, 0.20 equivalents of sodium acetate (CH ₃ COONa) powder, 1.65 equivalents of N-methyl-2-pyrrolidone (NMP) and 4.72 equivalents of distilled water were added to the reactor. The reactor was heated to 205 ° C. for 1 hour with stirring at 150 rpm to carry out a dehydration reaction, and the remaining mixture obtained after the dehydration reaction was obtained as a sulfur source. At this time, the measured NMP concentration (v / v%) in the dehydration liquid that was removed to the outside while performing the dehydration reaction was 28.9% as measured by gas chromatography. In addition, the molar ratio of H ₂ O / S in the remaining mixture obtained as the sulfur source was calculated to be 1.72.

(2) polymerization reaction

After the temperature of the reactor including the sulfur source obtained through the dehydration reaction was lowered to below 170 ° C., 1.04 equivalents of para-dichlorobenzene (p-DCB) and 1.65 equivalents of NMP were added to the reactor. At this time, the molar ratio of NMP / S was calculated to be 2.95. And the obtained mixed solution was heated to 230 degreeC and made to react for 2 hours, and also it heated up to 270 degreeC and made to react for 2 hours further. After the reaction was completed, 3 equivalents of distilled water was added into the reactor with respect to 1 equivalent of sulfur present in the reactor, and the resultant was recovered after sufficiently lowering the temperature. The resultant was filtered using a mixed solution of distilled water and NMP (mixed volume ratio = 1: 1), but polyphenylene sulfide particles could not be obtained.

Comparative Example 8

In order to make a PPS polymer, a dehydration reaction (first step) and a polymerization reaction (second step) were performed according to the method as shown in FIG. 1.

(1) dehydration reaction

Sodium sulfide (Na2S) was prepared by mixing 1.00 equivalents of sodium hydrogen sulfide (NaSH) and 1.05 equivalents of sodium hydroxide (NaOH) in a reactor. At this time 0.44 equivalents of sodium acetate (CH3COONa) powder, 1.65 equivalents of N-methyl-2-pyrrolidone (NMP) and 4.72 equivalents of distilled water were added to the reactor. The reactor was heated to 185 ° C. for 1 hour with stirring at 150 rpm to carry out a dehydration reaction, and the remaining mixture obtained after the dehydration reaction was obtained as a sulfur source. At this time, the measured NMP concentration (v / v%) in the dehydration liquid that was removed to the outside while performing the dehydration reaction was 30.2% as measured by gas chromatography. In addition, the molar ratio of H _{2 O} / S in the remaining mixture obtained as the sulfur source was calculated to be 2.26.

(2) polymerization reaction

After the temperature of the reactor including the sulfur source obtained through the dehydration reaction was lowered to below 170 ° C., 1.04 equivalents of para-dichlorobenzene (p-DCB) and 1.35 equivalents of NMP were added to the reactor. At this time, the molar ratio of NMP / S was calculated to be 2.63. And the obtained mixed solution was heated to 220 degreeC and made to react for 2 hours, and it heated up again to 250 degreeC and made it react for further 2 hours. After the reaction was completed, 3 equivalents of distilled water was added into the reactor with respect to 1 equivalent of sulfur present in the reactor, and the resultant was recovered after sufficiently lowering the temperature. The resultant was washed sequentially with a mixture of distilled water and NMP (mixed volume ratio = 1: 1) and distilled water, followed by filtration, washed with NMP for 10 minutes at 90 ° C., and filtered, and then, 90% with an aqueous 0.4% acetic acid solution. After washing at ℃ and filtered, and again filtered at 90 ℃ for 10 minutes with distilled water. The washed polyphenylene sulfide was recovered by drying in a vacuum oven at 150 ° C. for 8 hours.

The yield of polyphenylene sulfide recovered at this time was 74.6%, and the viscosity was 38.3 Pa · S.

Comparative Example 9

In order to make a PPS polymer, a dehydration reaction (first step) and a polymerization reaction (second step) were performed according to the method as shown in FIG. 1.

(1) dehydration reaction

Sodium sulfide (Na2S) was prepared by mixing 1.00 equivalents of sodium hydrogen sulfide (NaSH) and 1.05 equivalents of sodium hydroxide (NaOH) in a reactor. At this time, 1.65 equivalents of N-methyl-2-pyrrolidone (NMP) and 4.72 equivalents of distilled water were added to the reactor. The reactor was heated to 185 ° C. for 1 hour with stirring at 150 rpm to carry out a dehydration reaction, and the remaining mixture obtained after the dehydration reaction was obtained as a sulfur source. At this time, the NMP concentration (v / v%) measured in the dehydration liquid which was removed to the outside while performing the dehydration reaction was 30.0% as measured by gas chromatography. In addition, the molar ratio of H ₂ O / S in the remaining mixture obtained as the sulfur source was calculated to be 1.50.

(2) polymerization reaction

After the temperature of the reactor including the sulfur source obtained through the dehydration reaction was lowered to below 170 ° C., 1.04 equivalents of para-dichlorobenzene (p-DCB) and 1.35 equivalents of NMP were added to the reactor. At this time, the molar ratio of NMP / S was calculated to be 2.60. And the obtained mixed solution was heated to 230 degreeC and made to react for 2 hours, and it heated up again to 250 degreeC and made it react for 2 hours further. After the reaction was completed, 3 equivalents of distilled water was added into the reactor with respect to 1 equivalent of sulfur present in the reactor, and the resultant was recovered after sufficiently lowering the temperature. The resultant was washed sequentially with a mixture of distilled water and NMP (mixed volume ratio = 1: 1) and distilled water, followed by filtration, washed with NMP for 10 minutes at 90 ° C., and filtered, and then, 90% with an aqueous 0.4% acetic acid solution. After washing at ℃ and filtered, and again filtered at 90 ℃ for 10 minutes with distilled water. The washed polyphenylene sulfide was recovered by drying in a vacuum oven at 150 ° C. for 8 hours.

The yield of polyphenylene sulfide recovered at this time was 64.8%, and the viscosity was 5.4 Pa · S.

Comparative Example 10

In order to make a PPS polymer, a dehydration reaction (first step) and a polymerization reaction (second step) were performed according to the method as shown in FIG. 1.

(1) dehydration reaction

Sodium sulfide (Na2S) was prepared by mixing 1.00 equivalents of sodium hydrogen sulfide (NaSH) and 1.05 equivalents of sodium hydroxide (NaOH) in a reactor. At this time, 0.44 equivalents of sodium acetate (CH3COONa) powder, 4.00 equivalents of N-methyl-2-pyrrolidone (NMP) and 4.72 equivalents of distilled water were added to the reactor. The reactor was heated to 185 ° C. for 1 hour with stirring at 150 rpm to carry out a dehydration reaction, and the remaining mixture obtained after the dehydration reaction was obtained as a sulfur source. At this time, the measured NMP concentration (v / v%) in the dehydration liquid that was removed to the outside while performing the dehydration reaction was 53.0% as measured by gas chromatography. In addition, the molar ratio of H ₂ O / S in the remaining mixture obtained as the sulfur source was calculated to be 1.64.

(2) polymerization reaction

After the temperature of the reactor including the sulfur source obtained through the dehydration reaction was lowered to below 170 ° C., 1.04 equivalents of para-dichlorobenzene (p-DCB) and 1.35 equivalents of NMP were added to the reactor. At this time, the molar ratio of NMP / S was calculated to be 4.05. And the obtained mixed solution was heated to 230 degreeC and made to react for 2 hours, and also it heated up to 260 degreeC and made to react for further 2 hours. After the reaction was completed, 3 equivalents of distilled water was added into the reactor with respect to 1 equivalent of sulfur present in the reactor, and the resultant was recovered after sufficiently lowering the temperature. The resultant was filtered using a mixed solution of distilled water and NMP (mixed volume ratio = 1: 1), but polyphenylene sulfide particles could not be obtained.

Test Example 1

Physical properties of the polyphenylene sulfide (PPS) prepared in Examples and Comparative Examples were measured by the following method, and the results are shown in Table 1 below.

1) Melt viscosity (Pa · S): Frequency sweeping method by placing each polyphenylene sulfide resin (about 5 to 10 g of dry sample weight) on an equilibrium plate using ARES-G2 (Advanced Rhoeometric Expansion System) Angular frequency was changed from 0.1 to 100 rad / s using the measured at 300 ℃.

2) Yield: After weighing the dried polyphenylene sulfide with an electronic balance, the number of moles was calculated based on the repeat unit value (108.16 g / mol). This yielded the yield of the polymer actually recovered (mol / mol%) based on the less molar sodium sulfide or the molar number of para-dichlorobenzene.

In Table 1, Comparative Example 7 and Comparative Example 10 did not produce polyphenylene sulfide (PPS) particles, so the physical property evaluation itself was impossible.

As shown in Table 1, in the polymerization step of the polyarylene sulfide, the dihalogenated aromatic compound was introduced at an optimum ratio of 1.04 to 1.08 equivalent to the hydrosulfide of the alkali metal, and at the same time, the dehydration reaction and the second step By performing all the polymerization processes under the optimum conditions, all of the polyarylene sulfides having a melt viscosity of 27.3 Pa.S to 73.8 Pa.S could be effectively produced with a high yield of 85% or more.

Claims (11)

1. Dehydration of an alkali metal hydrosulfide and an alkali metal hydroxide is carried out in a mixed solvent of water and an amide compound in the presence of an organic acid salt of an alkali metal at a temperature of 185 ° C or more and 205 ° C or less to thereby dehydrate the alkali metal. A first step of preparing a sulfur source comprising a sulfide of and a mixed solvent of water and an amide compound; And

   A dihalogenated aromatic compound and an amide compound are added to the reactor containing the said sulfur source, and it superposes | polymerizes at the temperature from 225 degreeC or more to 245 degreeC or less, and then heats up at temperature from 250 degreeC or more to 260 degreeC or less, and superposes | polymerizes. To prepare a polyarylene sulfide;

   Including,

   The dehydration liquid removed during the dehydration reaction of the first step, 15% (v / v) to 35% (v / v) of the amide compound based on the total volume,

   In the second step of the polymerization reaction, the dihalogenated aromatic compound is used in an equivalence ratio of 1.04 to 1.08 based on 1 equivalent of the hydrosulfide of the alkali metal, the production method of polyarylene sulfide.
2. The method of claim 1,

   The organic acid salt of the alkali metal is used in an equivalent ratio of 0.01 to 1.0 with respect to 1 equivalent of the hydrosulfide of the alkali metal,

   Process for preparing polyarylene sulfide.
3. The method of claim 1,

   The organic acid salt of the alkali metal includes lithium acetate, sodium acetate, or a mixture thereof.

   Process for preparing polyarylene sulfide.
4. The method of claim 1,

   The water in the first step is used in an equivalent ratio of 1 to 8 with respect to 1 equivalent of the amide compound,

   Process for preparing polyarylene sulfide.
5. The method of claim 1,

   The sulfur source prepared in the first step comprises water in a molar ratio of 1.5 to 3.5 with respect to 1 mol of sulfur,

   Process for preparing polyarylene sulfide.
6. The method of claim 1,

   Before proceeding to the second step, further comprising the step of lowering the temperature of the reactor containing the sulfur source from more than 150 ℃ to less than 200 ℃,

   Process for preparing polyarylene sulfide.
7. The method of claim 1,

   In the second step, the amide compound is added so as to have a molar ratio of 2.5 to 4.0 with respect to 1 mole of sulfur.

   Process for preparing polyarylene sulfide.
8. The method of claim 1,

   The dihalogenated aromatic compounds include o-dihalobenzene, m-dihalobenzene, p-dihalobenzene, dihalotoluene, dihalonaphthalene, dihalobiphenyl, dihalobenzoic acid, dihalodiphenyl ether, dihalodiphenyl sulfone, It contains any one or two or more selected from the group consisting of dihalodiphenyl sulfoxide and dihalodi diphenyl ketone,

   Process for preparing polyarylene sulfide.
9. The method of claim 1,

   Wherein the polyarylene sulfide is produced in a yield of at least 85% and has a melt viscosity of 20 Pa.S to 150 Pa.S.

   Process for preparing polyarylene sulfide.
10. The method of claim 1,

    After the polymerization reaction in the second step, further comprising the step of adding water to the reaction mixture in an equivalent ratio of 3 to 5 relative to 1 equivalent of sulfur, and cooling.

    Process for preparing polyarylene sulfide.
11. The method of claim 10,

    After the cooling step, further comprising the step of washing and then drying the reaction mixture using water and an amide compound,

    Process for preparing polyarylene sulfide.

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