JP2007009128A - Method for producing slurry containing alkali metal sulfide and method for producing polyarylene sulfide by using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a simple and economical method for producing slurry containing an alkali metal sulfide having high fluidity and provide a method for efficiently producing a polyarylene sulfide by using the slurry. <P>SOLUTION: The method for producing an alkali metal sulfide having high fluidity is characterized by the addition of (a) an organic polar solvent to an alkali metal sulfide free from water or having low water content. The invention further provides a method for producing a polyarylene sulfide by using the product. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for producing a slurry containing alkali metal sulfide having high fluidity, and a method for producing polyarylene sulfide using the slurry. More specifically, the present invention relates to a method for producing a slurry containing alkali metal sulfide having high fluidity by an economical and simple method, and a method for efficiently producing polyarylene sulfide using the slurry.

  In recent years, special physical properties of organic sulfur compounds, particularly aliphatic sulfur compounds and aromatic sulfur compounds (thiols, thioketones, thioethers, thioacids, etc.) have attracted attention and are frequently used in medicines, agricultural chemicals, industrial chemicals, and the like. In addition, a large number of aromatic polymer compounds (polyarylene sulfide, hereinafter sometimes abbreviated as PAS) having sulfur as a bond are also produced. Such a sulfur-containing aromatic polymer compound is usually produced by contacting and reacting a halogenated aromatic compound and an alkali metal sulfide to remove the alkali metal halide, for example, polyarylene. The sulfide can be obtained by polymerizing a polyhalogenated aromatic compound and an alkali metal sulfide in contact with each other in an organic polar solvent.

  As a specific method for producing this PAS, in an organic amide solvent such as N-methyl-2-pyrrolidone (hereinafter sometimes abbreviated as NMP), an alkali metal sulfide such as sodium sulfide and a polyhalo such as p-dichlorobenzene are used. A method of reacting with an aromatic compound has been proposed, but only a PAS having a low molecular weight and a low melt viscosity can be obtained. In addition, a commonly practiced method is to remove the water contained in the hydrous sodium sulfide by heating sodium sulfide containing a large amount of water of crystallization in one or more moles of an organic amide solvent per mole of the sulfur component of the sodium sulfide. In this method, a sulfidizing agent is prepared by adding p-dichlorobenzene and polymerized by heating. Not only does it take a long time to remove the water from the hydrous sodium sulfide, but also the sulfide obtained by this method. As the agent, 1.0 mol or more of water per 1 mol of sulfur component of the sulfidizing agent remains, so that it takes a long time to obtain PAS (for example, see Patent Document 1). .

The problem in the above method, that is, the method of controlling the amount of water in the reaction system is polymerization using an alkali metal sulfide anhydride having a purity of 95 wt% or more and an alkali metal hydrosulfide contained as impurities of 2 wt% or less. Water is added to the system in an amount of 0.1 to 0.8 mole per mole of alkali metal sulfide, and the molar concentration of alkali metal sulfide to the organic amide solvent is set to 2.5 to 5 mole / liter. A method of heating and reacting an alkali metal sulfide and a dihaloaromatic compound (see, for example, Patent Document 2), one or more selected from alkali metal sulfides and alkaline earth metal sulfides, wherein water / sulfide A metal sulfide having a molar ratio of 1.2 or less is mixed with at least one polymerization aid selected from the group consisting of metal chlorides, metal carbonates, and metal carboxylates. And a dihalogen aromatic compound using a low water content alkali metal sulfide having a water content per mole of sulfur component of the alkali metal sulfide of 0.5 mol. A method of reacting (for example, see Patent Document 3), a polysulfide sulfide obtained by reacting a metal sulfide having a water content in the reaction system of 0.3 to 0.95 mol per sulfur source and a dihalogenated aromatic compound. (Hereinafter, also abbreviated as PPS) (for example, see Patent Document 4), an aqueous mixture comprising a sulfur source and a polar organic compound is dehydrated to form a mixture, provided that in this case The molar ratio of the polar organic compound to the sulfur source should be in the range of 0.15 / 1 to about 0.9 / 1, and the dehydrated mixture and the polyhalo-substituted aromatic compound may optionally be In the presence of an additional polar organic compound to produce a polymerization mixture, and the polymerization mixture is subjected to a polymerization reaction under conditions effective to cause a polymerization reaction (see, for example, Patent Document 5). ), And the organic amide solvent and water are removed from the mixture containing 0.8 to 10 moles of organic amide solvent and 0.8 to 20 moles of water per mole of the sulfur component of the alkali metal sulfide. Low water content alkali metal sulfides with water content and organic amide solvent amount adjusted to 0.05 mol or more and less than 0.8 mol, respectively, per mol of sulfur component of alkali metal sulfide, and dihalogenated aromatic in organic polar solvent A method of polymerizing by contacting with a compound (for example, see Patent Document 6) has been disclosed, but the metal sulfide obtained from any of the methods has a low water content, so it has poor fluidity. Had problems. Therefore, when the reactor in which the metal sulfide is prepared and the reactor in which the preparation is used to contact the dihalogenated aromatic compound in an organic polar solvent to produce PAS are different, the former reactor ( In the process of transferring from 1) to the latter reactor (2), there were problems such as longer transferability and increased residual amount of metal sulfide in the reactor (1). Longer transfer time leads to lower productivity. Further, the increase in the residual amount of metal sulfide in the reactor (1) is the ratio of the composition contained in the metal sulfide transferred to the reactor (2) and the metal sulfide remaining in the reactor (1). Due to the difference, it is difficult to adjust the amount of the dihalogenated aromatic compound and the organic polar solvent to be added so that the polymerization in the reactor (2) can be performed satisfactorily, and at the same time, it remains in the reactor (1). Since the amount of metal sulfide consumed during the polymerization in the reactor (2) is reduced by the amount of metal sulfide, the productivity per unit is lowered. Therefore, a method for solving these problems, that is, a method for improving the fluidity of metal sulfides has been desired.
Japanese Examined Patent Publication No. 45-3368 (page 13) JP-A-4-145127 (pages 2 and 3) JP-A-64-9229 (pages 3 to 5) JP 59-98133 A (page 2) JP 5-239210 A (page 3) Japanese Unexamined Patent Publication No. 2005-054181 (2nd page)

  The present invention has been achieved as a result of studying the solution of the above-mentioned problems as an object. Accordingly, an object of the present invention is to provide a method for producing a slurry containing alkali metal sulfide having high fluidity by an economical and simple method, and a method for producing polyarylene sulfide efficiently using the slurry. .

  The present invention employs the following means in order to solve such problems. That is, a method for producing a slurry containing a good-flowing alkali metal sulfide, wherein (a) an organic polar solvent is added to anhydrous and / or low water content alkali metal sulfide.

  In addition, a polyarylene sulfide production method characterized in that the slurry containing the good-flowing alkali metal sulfide thus obtained is polymerized by contacting with a dihalogenated aromatic compound in an organic polar solvent. is there.

That is, the present invention
(1) (b) A method for producing a slurry containing an alkali metal sulfide, wherein (a) an organic polar solvent is added to the anhydrous alkali metal sulfide and / or the low hydrous alkali metal sulfide,
(2) (b) The low water content alkali metal sulfide is a low water content alkali metal sulfide containing less than 1.5 moles of water per mole of sulfur component of the alkali metal sulfide. A method for producing a slurry containing an alkali metal sulfide of
(3) At least (b) alkali metal sulfide, 0.8 to 10 moles of (c) organic amide solvent per mole of sulfur component of the alkali metal sulfide, and 0 per mole of sulfur component of the alkali metal sulfide. (C) The organic amide solvent and (d) water are removed from the mixture containing 8 to 20 moles of (d) water, and the water content and the organic amide solvent amount in the mixture are changed to sulfur component 1 of alkali metal sulfide. Production of slurry containing alkali metal sulfide characterized by adding (a) organic polar solvent to (b) low water content alkali metal sulfide adjusted to 0.05 mol or more and less than 0.8 mol, respectively, per mole Method,
(4) (a) The addition amount of the organic polar solvent is 0.01 mol or more and 14.2 mol or less per mol of the sulfur component of (b) alkali metal sulfide, and any one of (1) to (3) A method for producing a slurry containing the alkali metal sulfide according to claim 1,
(5) A method for producing a slurry containing an alkali metal sulfide according to any one of (1) to (4), wherein (a) an organic polar solvent is added to (b) the alkali metal sulfide at 180 ° C. or higher,
(6) A method comprising polymerizing a slurry containing an alkali metal sulfide obtained by the production method according to any one of (1) to (5) and a dihalogenated aromatic compound in an organic polar solvent. And (7) a slurry containing an alkali metal sulfide prepared in the reactor (1) by the production method according to any one of claims 1 to 5 and then containing the alkali metal sulfide. The method for producing polyarylene sulfide according to (6), wherein the slurry is transferred to the reactor (2) and brought into contact with the dihalogenated aromatic compound.

  ADVANTAGE OF THE INVENTION According to this invention, the method of manufacturing the slurry containing an alkali metal sulfide with high fluidity | liquidity by an economical and simple method, and the method of manufacturing polyarylene sulfide efficiently using this can be provided. .

  In the present invention, anhydrous or low hydrous alkali metal sulfide is used as a raw material of a slurry containing a good-flowing alkali metal sulfide. However, in order to efficiently produce polyarylene sulfide, low hydrous alkali metal sulfide should be used. Is preferred.

  Regarding the method for producing (A) PAS in the present invention, an alkali metal sulfide, an organic amide solvent, water, a low hydrous alkali metal sulfide production step, a slurry production method containing an alkali metal sulfide, and an alkali metal sulfide are hereinafter described. Including slurry, PAS, organic polar solvent, dihalogenated aromatic compound, catalyst compound, polymerization aid, molecular weight regulator / branching / crosslinking agent, polymerization stabilizer, polymerization process, polymer recovery, other post-treatment and production PAS in this order Detailed description.

-Alkali metal sulfide In this invention, an alkali metal sulfide is used as a raw material of a low hydrous alkali metal sulfide. Specific examples of the alkali metal sulfide include, for example, lithium sulfide, sodium sulfide, potassium sulfide, rubidium sulfide, cesium sulfide, and a mixture of two or more of these, and sodium sulfide is preferably used. These alkali metal sulfides can be used as hydrates or aqueous mixtures or in the form of anhydrides. The aqueous mixture refers to an aqueous solution, a mixture of an aqueous solution and a solid component, or a mixture of water and a solid component. Since generally available inexpensive alkali metal sulfides are hydrates or aqueous mixtures, it is preferred to use such forms of alkali metal sulfides.

  Further, an alkali metal sulfide prepared from an alkali metal hydrosulfide and an alkali metal hydroxide and / or an alkali metal hydroxide and hydrogen sulfide can also be used as the same alkali metal sulfide as described above. Here, when preparing an alkali metal sulfide from an alkali metal hydrosulfide and an alkali metal hydroxide, 1 mol of the alkali metal sulfide and 1 mol of the alkali metal sulfide and 1 water of 1 mol of the alkali metal hydrosulfide and 1 mol of the alkali metal hydroxide. It is assumed that moles are formed. Moreover, when preparing an alkali metal sulfide from an alkali metal hydroxide and hydrogen sulfide, it is considered that 1 mol of alkali metal sulfide and 2 mol of water are generated from 2 mol of alkali metal hydroxide and 1 mol of hydrogen sulfide.

  Specific examples of the alkali metal hydrosulfide include, for example, sodium hydrosulfide, potassium hydrosulfide, lithium hydrosulfide, rubidium hydrosulfide, cesium hydrosulfide and a mixture of two or more of these. Sodium sulfide is preferably used. These alkali metal hydrosulfides can be used as a hydrate or an aqueous mixture or in the form of an anhydride, and the hydrate or the aqueous mixture is preferable from the viewpoint of availability and cost. Further, hydrogen sulfide can be used in any form of gas, liquid, and aqueous solution.

  Specific examples of the alkali metal hydroxide include, for example, lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide, and a mixture of two or more thereof. Sodium hydroxide is preferably used. These alkali metal hydroxides can be used as a hydrate or an aqueous mixture or in the form of an anhydride, and the hydrate or the aqueous mixture is preferable from the viewpoint of availability and cost. When the alkali metal hydrosulfide is used, the amount of the alkali metal hydroxide used is 1.0 to 1.20 mol, preferably 1.005 to 1.15 mol, based on 1 mol of the sulfur component of the alkali metal hydrosulfide. More preferably, the range of 1.02-1.10 mol can be illustrated. The amount of alkali metal hydroxide used in the case of using hydrogen sulfide is 2.0 to 2.40 mol, preferably 2.01 to 2.30 mol, more preferably 2.04 to 2.2. A range of 20 moles can be exemplified.

(2) Organic amide solvent In the present invention, an organic amide solvent is used in the production of a low water content alkali metal sulfide. Specific examples of the organic amide solvent include N-alkylpyrrolidones such as N-methyl-2-pyrrolidone and N-ethyl-2-pyrrolidone, caprolactams such as N-methyl-ε-caprolactam, 1,3-dimethyl- 2-Imidazolidinone, N, N-dimethylacetamide, N, N-dimethylformamide, hexamethylphosphoric triamide, and mixtures thereof are preferably used. Among these, N-methyl-2-pyrrolidone (hereinafter sometimes abbreviated as NMP) is preferably used.

  The amount of the organic amide solvent used at the start of production of the low hydrous alkali metal sulfide is 0.8 to 10 mol per mol of the sulfur component of the alkali metal sulfide, and the lower limit is preferably 0.85 mol or more, The amount is more preferably 0.9 mol or more, further preferably 0.95 mol or more, and even more preferably 1.1 mol or more. As an upper limit, it is more preferable that it is 3.0 mol or less, it is more preferable that it is 2.0 mol or less, and it is still more preferable that it is 1.5 mol or less. If the amount is too small, metal elution from the container tends to increase when a metal container is used for the reaction. If the amount is too large, the time required for the reaction becomes long, which is economically disadvantageous.

(3) Water In the present invention, water is used in the production of the low water content alkali metal sulfide. Water as used herein means all water present in the reaction system at the start of production of the low water content alkali metal sulfide. Water added to the reaction system, hydrate of alkali metal sulfide and / or aqueous solution It includes all of water introduced into the reaction system as a mixture, water introduced into the reaction system as a water-containing organic amide solvent, water introduced into the reaction system as other water-containing compounds, and the like. In addition, when the alkali metal sulfide is prepared from an alkali metal hydrosulfide and an alkali metal hydroxide, and / or when prepared from an alkali metal hydroxide and hydrogen sulfide, the water generated along with the generation of the alkali metal sulfide. Is also included in the water described above. In addition, when water is by-produced by the reaction of components other than the above that coexist in the production of the low hydrous alkali metal sulfide, this water is also included in the water.

  The amount of water in the mixture at the start of production of the low hydrous alkali metal sulfide must be 0.8 to 20 mol per mol of the sulfur component of the alkali metal sulfide, and the lower limit is 1.0 mol or more. It is preferable that it is 2.0 mol or more. As an upper limit, it is preferable that it is 15 mol or less, and it is more preferable that it is 10 mol or less. If the amount is too small, metal elution from the container tends to increase when a metal container is used for the reaction. If the amount is too large, the time required for the reaction becomes long, which is economically disadvantageous.

(4) Low hydrous alkali metal sulfide production process In the method for producing low hydrous alkali metal sulfide, at least alkali metal sulfide, 0.8 to 10 moles of organic amide solvent per mole of sulfur component of alkali metal sulfide, alkali The organic amide solvent and the water are removed from the mixture containing 0.8 to 20 moles of water per mole of the sulfur component of the metal sulfide, and the water content and the organic amide solvent amount in the mixture are respectively changed to the sulfur component 1 of the alkali metal sulfide. Adjust to 0.05 mol or more and less than 0.8 mol per mol. Here, the amount of water and the organic amide solvent in the mixture is obtained by subtracting the amount of water and the organic amide solvent removed from the reaction system from the charged amount (including the case where the raw material is generated from the charged raw material). Indicates quantity.

  The water content in the mixture after removing water and the organic amide solvent from the mixture is not less than 0.05 mol and less than 0.8 mol per mol of the sulfur component of the alkali metal sulfide, and is 0.1 to 0.75. Mole is preferable, and 0.1 to 0.7 mol is more preferable. Further, in the production of PAS described later, when the production of PAS is carried out under the condition that the polymerization solvent is small, the water content is preferably 0.1 to 0.7 mol, more preferably 0.1 to 0.6 mol, and 15 to 0.5 mol is even more preferable. The amount of the organic amide solvent in the mixture after removing water and the organic amide solvent from the mixture is 0.05 mol or more and less than 0.8 mol per mol of the sulfur component of the alkali metal sulfide, -0.75 mol is preferable and 0.1-0.7 mol is more preferable. Further, in the production of PAS described later, when the production of PAS is carried out under the condition that the polymerization solvent is small, the water content is preferably 0.1 to 0.7 mol, more preferably 0.1 to 0.6 mol, and 15 to 0.5 mol is even more preferred. If the amount is too small, the viscosity of the produced low water content alkali metal sulfide tends to be too high and the handling tends to be difficult. If the amount is too large, a long time is required for the reaction when producing PAS.

  The method for adjusting the amounts of the organic amide solvent and water in the mixture to the above ranges is not particularly limited as long as the adjustment is possible, but for example, the following liquid removal step is preferably employed. That is, a mixture of at least an alkali metal sulfide, an organic amide solvent, and water is preferably prepared in an inert gas atmosphere at a temperature ranging from room temperature to 150 ° C., preferably from room temperature to 100 ° C. An example is a method in which the organic amide solvent and water are distilled off by raising the temperature to not lower than 170 ° C., preferably not lower than 170 ° C. The preferable upper limit of the temperature at which the organic amide solvent and water are distilled off is 280 ° C. Moreover, in order to accelerate | stimulate distillation, you may distill while stirring, Desirably you may distill through the stream of an inert gas, Moreover, you may distill by adding toluene etc. Good.

  Moreover, when producing a low water content alkali metal sulfide by the said liquid removal process, it is preferable that a liquid removal process contains the following 2 processes at least.

  Step 1: Dehydrating the mixture below the boiling point of the organic amide solvent to adjust the water content to 0.8 mol to 2.0 mol per mol of the sulfur component of the alkali metal sulfide charged.

  Step 2; The mixture prepared in Step 1 is drained at a temperature equal to or higher than the boiling point of the organic amide solvent, water and the organic amide solvent are removed, and the water content and the amount of the organic amide solvent in the mixture are changed to sulfur components of the alkali metal sulfide. The process of adjusting each 0.05 mol or more and less than 0.8 mol per mol.

  Here, it is preferable to perform the process 2 continuously after the process 1, and there may exist additional processes, such as a pre-processing process and a post-processing process, besides these processes. Further, Step 1 and Step 2 may be carried out in the same reactor, and there is no problem even if Step 2 is carried out by transferring the reaction mixture from the reactor carrying out Step 1 to a different container. Hereinafter, step 1 and step 2 will be described in detail.

  <Step 1> In the production of a low water content alkali metal sulfide, a mixture containing at least the alkali metal sulfide, the organic amide solvent and water in the above ranges is dehydrated below the boiling point of the organic amide solvent, and the water content is reduced. Step 1 of adjusting the charged alkali metal sulfide to 0.8 to 2.0 mol, preferably 0.9 to 1.7 mol, more preferably 0.95 to 1.5 mol per 1 mol of the sulfur component of the alkali metal sulfide is performed. It is preferable. Even if these amounts are too small or too large, metal elution from the container tends to increase when a metal container is used for the reaction. Although there is no restriction | limiting in particular as this liquid removal method, For example, the liquid removal process which heats under the above-mentioned inert gas under normal pressure or pressure reduction and performs liquid removal can be employ | adopted preferably. In addition, it is preferable to perform the liquid removal in the process 1 below the boiling point of an organic amide solvent, and this specific temperature is the kind of organic amide solvent to be used, the composition of the liquid mixture to perform liquid removal, the pressure at the time of liquid removal, etc. However, it is more preferable to carry out at 230 ° C. or less, particularly preferably at 210 ° C. or less. This tends to reduce metal elution from the container when a metal container is used for the reaction. Further, the lower limit is not particularly limited as long as the liquid can be drained within a desired range, but from the viewpoint of the liquid draining efficiency, it is preferably 150 ° C. or higher, and more preferably 170 ° C. or higher. In addition, it is possible to distill off the organic amide solvent together with water during the liquid removal in step 1, but in step 1, the amount of organic amide solvent in the reaction system is 0.8 mol per mol of sulfur component of the alkali metal sulfide. Preferably, it is 0.9 mol or more, more preferably 0.95 mol or more, and even more preferably 1.1 mol or more. This tends to further suppress metal elution from the container when a metal container is used. Therefore, when the organic amide solvent is distilled off together with water during the liquid removal in step 1, it is preferable to separate the distilled organic amide solvent again and return it to the reaction system. This method includes rectification. be able to.

  <Step 2> In the production of the low water content alkali metal sulfide, the mixture prepared in Step 1 is dehydrated at a temperature equal to or higher than the boiling point of the organic amide solvent, water and the organic amide solvent are removed, and the amount of water in the mixture and It is preferable to perform Step 2 of adjusting the amount of the organic amide solvent to 0.05 mol or more and less than 0.8 mol, respectively, per 1 mol of the sulfur component of the alkali metal sulfide. The amount of water in the mixture after removing water and the organic amide solvent in Step 2 is 0.05 mol or more and less than 0.8 mol per mol of the sulfur component of the alkali metal sulfide. 75 mol is preferable, and 0.1 to 0.7 mol is more preferable. Furthermore, in the production of PAS to be described later, when the production of PAS is carried out under the condition that the polymerization solvent is small, the water content is preferably 0.1 to 0.7 mol, more preferably 0.1 to 0.6 mol, 0 15 to 0.5 moles is even more preferred. The amount of the organic amide solvent is 0.05 mol or more and less than 0.8 mol per mol of the sulfur component of the alkali metal sulfide, preferably 0.1 to 0.75 mol, more preferably 0.1 to 0.7 mol. preferable. Further, in the production of PAS described later, when the production of PAS is carried out under the condition that the polymerization solvent is small, the water content is preferably 0.1 to 0.7 mol, more preferably 0.1 to 0.6 mol, and 15 to 0.5 mol is even more preferable. When these amounts are too large, a long time is required for the reaction when producing PAS. A method for adjusting the amount of the organic amide solvent and water in such a mixture is not particularly limited. For example, the liquid removal step of performing liquid removal by heating at normal pressure or reduced pressure under the above-described inert gas. Is preferably adopted. In addition, it is preferable to perform the liquid removal in the step 2 above the boiling point of the organic amide solvent, and this specific temperature depends on the type of the organic amide solvent to be used, the composition of the mixture for liquid removal, the pressure at the time of liquid removal, etc. Although it is different and cannot be defined generally, it is more preferably carried out at a temperature exceeding the boiling point of the organic amide solvent, more preferably at 210 ° C. or higher, and particularly preferably at 230 ° C. or higher. This tends to remove water and organic amide solvent in a short time. Further, the upper limit is not particularly limited as long as each content after liquid removal is within the above range, but it is preferably 280 ° C. or lower, and more preferably 270 ° C. or lower.

(5) Slurry production process including alkali metal sulfide The low water content alkali metal sulfide described above is preferably used as a method for efficiently producing PAS, which will be described later. In order to produce a sulfide slurry, it is necessary to add (a) an organic polar solvent to the low water content alkali metal sulfide. (A) An organic amide solvent is preferably used as the organic polar solvent, and specific examples thereof include N-alkylpyrrolidones such as N-methyl-2-pyrrolidone and N-ethyl-2-pyrrolidone, and N-methyl-ε. -Aprotic organic solvents represented by caprolactams such as caprolactam, 1,3-dimethyl-2-imidazolidinone, N, N-dimethylacetamide, N, N-dimethylformamide, hexamethylphosphoric triamide, and the like, and A mixture or the like is preferably used. Of these, N-methyl-2-pyrrolidone is preferably used.

  When producing a slurry containing an alkali metal sulfide in the present invention, an anhydrous alkali metal sulfide and / or a low hydrous alkali metal sulfide is used as the alkali metal sulfide, but a low hydrous alkali metal sulfide is used. Preferably, a low hydrous alkali metal sulfide containing less than 1.5 mol of water per mol of the sulfur component of the alkali metal sulfide produced by the above-described method can be preferably used.

  In the present invention, the amount of the (a) organic polar solvent added to the low hydrous alkali metal sulfide is preferably 0.01 mol or more. (A) If the amount of the organic polar solvent is too small, the fluidity of the low hydrous alkali metal sulfide slurry cannot be significantly improved. Although there is no restriction | limiting in particular about the upper limit of addition amount, (a) If there are too many organic polar solvents, since the organic polar solvent in a subsequent superposition | polymerization process will also increase, even with the usage-amount of a small polymerization solvent, injection molding, extrusion molding, etc. It is uneconomical in the present invention that it is possible to produce PAS suitable for various uses of commercial resins. Therefore, the amount of (a) organic polar solvent added is preferably 0.01 to 14.2 mol, more preferably 0.05 to 3.0 mol, and more preferably 0.001 mol per mol of the sulfur component of the low hydrous alkali metal sulfide. 1-2 moles are even more preferred.

  The temperature at which (a) the organic polar solvent is added to the low hydrous alkali metal sulfide is preferably 180 ° C. or higher, preferably 190 ° C. or higher, and more preferably 200 ° C. or higher. If the temperature is too low, (a) the low hydrous alkali metal sulfide solidifies before the addition of the organic polar solvent, making it difficult to obtain a uniform, good-flowing alkali metal sulfide slurry. Although there is no restriction | limiting in particular about the upper limit of addition temperature, As a preferable temperature, 280 degrees C or less can be illustrated. If it is 280 ° C. or higher, the boiling point of the organic polar solvent is greatly exceeded, so that significant boiling occurs simultaneously with the addition of the solvent, which is not preferable for safety.

  (A) Although there is no restriction | limiting in particular in the method of adding an organic polar solvent, For example, the method of adding under pressure conditions, the method of adding using a pump, and the method of adding using self-weight can be illustrated. At that time, it is preferable as an efficient production method to uniformly disperse the added (a) organic polar solvent and to remove the low hydrous alkali metal sulfide adhering to the reactor. In addition, (a) the organic polar solvent may be added to the reactor in any of an open system and a closed system. Water or an organic amide solvent contained in the low hydrous alkali metal sulfide and further added (a) organic It is preferable that the polar solvent does not leak out of the system.

(6) Slurry containing alkali metal sulfide The slurry containing the good-flowing alkali metal sulfide thus prepared is brought into contact with a dihalogenated aromatic compound in an organic polar solvent to produce polyarylene sulfide. In particular, it is particularly preferably used.

  There is no particular limitation on the method of contacting the prepared good-flowing alkali metal sulfide slurry with PA in the organic polar solvent by contacting with a dihalogenated aromatic compound, but the following methods are exemplified. it can.

  (A) An alkali metal sulfide slurry prepared in advance is charged into a reactor, and an organic polar solvent, a dihalogenated aromatic compound, and a catalyst compound described later as necessary are charged before and / or during the temperature increase, and the reactor A method of polymerizing at a polymerization temperature after sufficiently stirring and mixing.

  (B) As a pre-process, preferably after preparing an alkali metal sulfide slurry obtained by the present invention in the presence of a catalyst compound, an organic polar solvent and a dihalogenated aromatic compound are added to the reactor used here, and A method of stirring and polymerizing at a polymerization temperature.

  (C) After preparing the alkali metal sulfide slurry according to the present invention in the reactor (1), preferably in the presence of a catalyst compound, the slurry is transferred to a reactor (2) different from the reactor (1) A method in which an organic polar solvent and a dihalogenated aromatic compound are further added to 2) and the mixture is sufficiently stirred and polymerized at the polymerization temperature.

  As a method for effectively utilizing the high fluidity characteristic of the alkali metal sulfide slurry according to the present invention, the above contact method (C), that is, the reactor for preparing the alkali metal sulfide slurry and the subsequent polymerization are performed. This is a method for producing PAS with different reactors. Moreover, (C) is a preferable method also from a viewpoint of production efficiency. There is no restriction | limiting in particular about the transfer method, For example, the transfer using piping can be mentioned. In addition, as described above, it is necessary to use (a) an organic polar solvent for the production of the alkali metal sulfide slurry, but (a) a method for further increasing the fluidity by further adding the organic polar solvent during the transfer. Can also be exemplified as a preferred method.

  The temperature of the reactor (2) immediately before being transferred from the reactor (1) to the reactor (2) is preferably 150 ° C. or higher, preferably 180 ° C. or higher, and more preferably 190 ° C. or higher. If the temperature is too low, (a) the alkali metal sulfide slurry to which the organic polar solvent is added is solidified in the reactor (2), and the dihalogenated aromatic compound or organic polar solvent used in the polymerization is added after the solidification. Since the solidified product does not tend to dissolve easily, poor polymerization is caused. In addition, after the transfer, the time until the temperature of the reactor (2) reaches the polymerization start temperature becomes long, which is inefficient. Although there is no restriction | limiting in particular in the upper limit of the temperature of a reactor (2), 280 degrees C or less can be illustrated as preferable temperature.

(7) PAS
The PAS in the present invention is a homopolymer or copolymer having a repeating unit of the formula, — (Ar—S) —, as a main constituent unit, and preferably containing 80 mol% or more of the repeating unit. Ar includes units represented by the following formulas (A) to (K), among which the formula (A) is particularly preferable.

(R1 and R2 are substituents selected from hydrogen, an alkyl group, an alkoxy group, and a halogen group, and R1 and R2 may be the same or different.)
As long as this repeating unit is a main structural unit, it can contain a small amount of branching units or crosslinking units represented by the following formulas (L) to (N). The amount of copolymerization of these branched units or cross-linked units is preferably in the range of 0 to 1 mol% with respect to 1 mol of-(Ar-S)-units.

  The PAS in the present invention may be any of a random copolymer, a block copolymer and a mixture thereof containing the above repeating unit.

  Furthermore, the molecular weight of various PASs is not particularly limited, but usually, a melt viscosity of 5 to 5,000 Pa · s (300 ° C., shear rate 1000 / second) can be exemplified as a preferable range.

  Typical examples of these include polyphenylene sulfide, polyphenylene sulfide sulfone, polyphenylene sulfide ketone, random copolymers thereof, block copolymers, and mixtures thereof. Particularly preferred PASs include p-phenylene sulfide units as the main structural unit of the polymer.

In addition to polyphenylene sulfide (hereinafter sometimes abbreviated as PPS) containing 80 mol% or more, particularly 90 mol% or more, polyphenylene sulfide sulfone and polyphenylene sulfide ketone.

(8) Organic Polar Solvent In the production of the PAS of the present invention, an organic polar solvent is used as a polymerization solvent, and an organic amide solvent is particularly preferable. Specific examples include N-alkylpyrrolidones such as N-methyl-2-pyrrolidone and N-ethyl-2-pyrrolidone, caprolactams such as N-methyl-ε-caprolactam, and 1,3-dimethyl-2-imidazolide. Non-, N, N-dimethylacetamide, N, N-dimethylformamide, aprotic organic solvents such as hexamethylphosphoric triamide, and mixtures thereof are preferably used because of their high reaction stability. Of these, N-methyl-2-pyrrolidone is preferably used. In addition, since the organic amide solvent used in the production of the low hydrous alkali metal sulfide and the organic polar solvent (a) used in the production of the alkali metal sulfide slurry are also included in the organic polar solvent used in the production of PAS, The organic amide solvent contained in the low hydrous alkali metal sulfide and the (a) organic polar solvent used in the production of the alkali metal sulfide slurry can also be regarded as a category of the organic polar solvent used in the production of PAS.

  Although there is no restriction | limiting in particular in the usage-amount of the organic polar solvent used as a polymerization solvent of PAS in this invention, The range of 0.2-15 mol per mol of sulfur components of an alkali metal sulfide can be illustrated. However, in the PAS production method of the present invention, a PAS suitable for various uses for the commercial use of resins such as injection molding and extrusion molding can be used even when the amount of polymerization solvent used is smaller than that of the conventional method. Since it can be produced, the amount of the organic polar solvent used as the polymerization solvent is preferably 1.0 to 4.0 mol, more preferably 1.0 to 3.3 mol per mol of the sulfur component of the alkali metal sulfide. 5 moles, more preferably 1.5 to 3.2 moles can be exemplified as a preferred range, and 1.5 to 2.7 moles is preferred when a significant improvement in polymer productivity is desired, and 1.5 to 2. 6 mol can be illustrated as a particularly preferable range. Generally, it is economically advantageous to use less polymerization solvent because the amount of polymer production per unit volume increases. However, if the amount is too small, undesirable reactions tend to occur, and if the amount is too large, the degree of polymerization tends not to increase. And may be economically disadvantageous. Further, if it is too much or too little, the time required for the reaction tends to become long, which may be disadvantageous economically. Here, the amount of the organic polar solvent in the reaction system is an amount obtained by subtracting the organic polar solvent removed from the reaction system from the organic polar solvent introduced into the reaction system.

(9) Dihalogenated aromatic compound Examples of the dihalogenated aromatic compound used in the production of the PAS of the present invention include dihalogenated benzenes such as p-dichlorobenzene, o-dichlorobenzene, m-dichlorobenzene, and p-dibromobenzene. And dihalogenated aromatic compounds containing a substituent other than halogen such as 1-methoxy-2,5-dichlorobenzene and 3,5-dichlorobenzoic acid. Especially, the dihalogenated aromatic compound which has p-dihalogenated benzene represented by p-dichlorobenzene as a main component is preferable. Particularly preferably, it contains 80 to 100 mol%, more preferably 90 to 100 mol% of p-dichlorobenzene. It is also possible to use a combination of two or more different dihalogenated aromatic compounds in order to produce a PAS copolymer.

  The amount of the dihalogenated aromatic compound is preferably in the range of 0.9 to 2.0 mol per mol of the sulfur component of the alkali metal sulfide from the viewpoint of obtaining a polyarylene sulfide having a viscosity suitable for processing. The range of 0.95-1.5 mol is more preferable, and the range of 1.005-1.2 mol is still more preferable.

(10) Catalyst compound In the present invention, when the alkali metal sulfide slurry is polymerized by contacting with a dihalogenated aromatic compound in an organic polar solvent, at least a part of the polymerization is an organic carboxylic acid metal salt, an aliphatic cyclic amine compound. , N-heteroaromatic compounds, organic sulfoxide compounds, and the like, preferably in the presence of at least one compound (hereinafter sometimes referred to as catalyst compound). Thereby, the reaction rate at the time of superposition | polymerization can be improved, and it exists in the tendency for a polymerization reaction to advance easily even if use of a very small amount of polymerization solvent. Here, increasing the reaction rate shortens the process time required for the polymerization reaction, and the use of a small amount of polymerization solvent increases the amount of polymer produced per unit volume of the reactor, thus producing an economically advantageous polymer. It is important for that. Among the catalyst compounds, the use of an organic carboxylic acid metal salt is preferable in that it can serve as a polymerization aid described later. Further, the reaction rate improving action by the catalyst compound is more preferably 0.05 mol or more and less than 0.8 mol, more preferably 0.05 to 0.8 mol in the presence of 0.05 to 0.8 mol of water per mol of the sulfur component in the reaction system. Tends to be expressed in the presence of 0.1 to 0.6 mol, particularly preferably 0.15 to 0.5 mol of water, and from this viewpoint, a polymerization reaction is performed using a low water content alkali metal sulfide. This is advantageous. The reason why the catalyst compound improves the reaction rate is not clear, but the catalytic compound interacts with the alkali metal sulfide in the reaction system to improve the solubility of the alkali metal sulfide in the reaction system. However, it is estimated that the reaction rate is improved by improving the contact probability between the alkali metal sulfide and the dihalogenated aromatic compound.

  The organic carboxylic acid metal salt has the general formula R (COOM) n (wherein R is an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group, an aryl group, an alkylaryl group, an arylalkyl group, an aminoalkyl group). N-alkylaminoalkyl group and N-phenylaminoalkyl group having 2 to 20 carbon atoms, among which an alkyl group, an aryl group and an N-alkylaminoalkyl group are preferable, and M is lithium, sodium, potassium , An alkali metal selected from rubidium and cesium, or an alkaline earth metal selected from magnesium, calcium, strontium and barium. N is an integer of 1 to 3). . Specific examples of the organic carboxylic acid metal salt include, for example, lithium acetate, sodium acetate, potassium acetate, magnesium acetate, calcium acetate, lithium propionate, sodium propionate, potassium propionate, lithium 4-hydroxybutyrate, 4-hydroxybutyric acid. Sodium, lithium N-methyl-4-aminobutyrate, sodium N-methyl-4-aminobutyrate, lithium N-ethyl-4-aminobutyrate, sodium N-ethyl-4-aminobutyrate, N-phenyl-4-aminobutyric acid Examples thereof include a compound selected from lithium, sodium N-phenyl-4-aminobutyrate, lithium valerate, sodium benzoate, sodium phenylacetate, potassium p-toluate, and mixtures thereof. An organic carboxylic acid metal salt is obtained by reacting an organic acid with one or more compounds selected from the group consisting of alkali metal hydroxides, alkali metal carbonates, and alkali metal bicarbonates, at approximately equal chemical equivalents. It may be formed. Among the above organic carboxylic acid metal salts, lithium salts are highly soluble in the reaction system and have a large catalytic effect, but are expensive, and potassium, rubidium, cesium, and alkaline earth metal salts are inferior in solubility in the reaction system. A sodium salt that is inexpensive and has an appropriate solubility in the polymerization system is preferably used.

  Specific examples of the aliphatic cyclic amine compound include piperazine, piperidine, pyrrolidine, N, N′-dimethylpiperazine, 1,4-diazabicyclo [2,2,2] octane, 1,5-diazabicyclo [4,3,0. ] -Non-5-ene, 1,8-diazabicyclo [5,4,0] -7-undecene, 1,5-diazabicyclo [4,4,0] -5-nonene, one kind selected from hexamethylenetetramine Examples thereof include compounds and mixtures thereof.

  Specific examples of the N-heteroaromatic compound are selected from pyridine, pyridazine, pyrimidine, sym-triazine, sym-tetrazine, quinoline, isoquinoline, quinazoline, 1,5-naphthyridine, pteridine, acridine, phenazine, and phenanthridine. One kind of compound and a mixture thereof may be mentioned.

  Specific examples of the organic sulfoxide compound include dimethyl sulfoxide and / or tetramethylene sulfoxide.

  Among the above catalyst compounds, sodium acetate is particularly preferable because it is inexpensive and easily available.

  At least one catalyst compound selected from organic carboxylic acid metal salts, aliphatic cyclic amine compounds, N-heteroaromatic compounds, and organic sulfoxide compounds can also be used as hydrates or aqueous solutions. The amount of these catalyst compounds used is 0.001 to 1.0 mol, preferably 0.01 to 0.7 mol, more preferably 0.02 to 0.6 mol, and more preferably 0.02 to 0.6 mol, per mol of sulfur component in the reaction system. When 0.05 to 0.45 mol is preferably present in the reaction system, a particularly large reaction promoting effect tends to be obtained. Therefore, the amount of catalyst compound used is preferably within the above range in order to obtain PAS in a short time.

(11) Polymerization aid In the production of the PAS of the present invention, a polymerization aid can be used in order to obtain a high degree of polymerization PAS in a shorter time. Here, the polymerization assistant refers to a substance having an action of increasing the viscosity of the obtained PAS. Specific examples of such a polymerization assistant include, for example, organic carboxylic acid metal salts, water, alkali metal chlorides, organic sulfonic acid metal salts, alkali metal sulfates, alkaline earth metal oxides, and alkali metal phosphates. And alkaline earth metal phosphates. These may be used alone or in combination of two or more. Among these, organic carboxylic acid metal salts and / or water are preferably used.

  The organic carboxylic acid metal salt is represented by the general formula R (COOM) n (wherein R is an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group, an aryl group, an alkylaryl group, or an arylalkyl group. , Sodium, potassium, rubidium, and cesium, and n is an integer of 1 to 3). The organic carboxylic acid metal salt can also be used as a hydrate or an aqueous solution. Specific examples of the organic carboxylate include lithium acetate, sodium acetate, potassium acetate, sodium propionate, sodium benzoate, sodium phenylacetate, potassium p-toluate, and a mixture thereof. The organic carboxylic acid metal salt is prepared by adding an organic acid and one or more compounds selected from the group consisting of an alkali metal hydroxide, an alkali metal carbonate, and an alkali metal bicarbonate to each other by adding approximately equal chemical equivalents. You may form by. Among the above organic carboxylic acid metal salts, potassium, rubidium and cesium salts are presumed to have poor solubility in the reaction system, and sodium acetate which is inexpensive and has an appropriate solubility in the reaction system is preferably used. .

  In addition, when an organic carboxylic acid metal salt is used as the catalyst compound described above, this may exhibit both an effect as a catalyst compound and an effect as a polymerization aid.

  The amount of the organic carboxylic acid metal salt used is preferably in the range of 0.01 to 0.7 mol, more preferably in the range of 0.02 to 0.6 mol, based on 1 mol of the sulfur component in the reaction system. A range of 0.05 to 0.45 mol is even more preferable. If the amount is less than the above range, the effect of increasing the degree of polymerization tends to be insufficient, and even if the amount exceeds the above range, the effect of increasing the degree of polymerization further tends to be difficult to obtain.

  When water is used as a polymerization aid, it is preferable to include a step in which the amount of water in the polymerization system is 0.8 to 5.0 moles per mole of sulfur component in the reaction system. The water content in the polymerization system is set to the above range, as described later, the conversion of the dihalogenated aromatic compound is 60 mol% or more, preferably 70% or more, more preferably 80% or more, and still more preferably 90%. % Is preferable. A more preferable range of the amount of water in the polymerization system is 0.8 to 2.0 mol, more preferably 0.85 to 1.8 mol, per mol of the sulfur component in the reaction system. If the water content in this case is less than the above range, a sufficient degree of polymerization effect may not be obtained. On the other hand, if it exceeds the above range, the polymerization time will not only become long, but also the internal pressure of the reactor. Therefore, a reactor having a high pressure resistance is required for the reactor, which tends to be unfavorable in terms of economy and safety.

  In addition, when water is used as a polymerization aid, it is preferable to use an organic carboxylic acid metal salt at the same time, which can further enhance the effect as a polymerization aid, and can be used in a short time even with a smaller amount of aid. It tends to be possible to obtain a degree of polymerization PAS. In this case, the preferable range of the amount of water is 0.8 to 2.0 mol, more preferably 0.85 to 1.8 mol, per mol of the sulfur component in the reaction system. Moreover, the range of the preferable usage-amount of organic carboxylic acid metal salt is the range of 0.02-0.6 mol per mol of sulfur components in a reaction system, and the range of 0.05-0.45 mol is more preferable. .

(12) Molecular weight regulator / branching / crosslinking agent In the production of the PAS of the present invention, a molecular weight regulator such as a monohalogen compound is used to form a terminal end of the produced PAS or to control the polymerization reaction or the molecular weight. (Not necessarily an aromatic compound) can be used in combination with the dihalogenated aromatic compound. In order to form a branched or cross-linked polymer, branching such as trihalogenated polyhalogen compounds (not necessarily aromatic compounds), active hydrogen-containing halogenated aromatic compounds, and halogenated aromatic nitro compounds. -A cross-linking agent can be used in combination. As the polyhalogen compound, a commonly used compound can be used. Among them, polyhalogenated aromatic compounds are preferable, and specific examples include 1,3,5-trichlorobenzene, 1,2,4-trichlorobenzene, Examples include 1,2,4,5-tetrachlorobenzene, hexachlorobenzene, 1,4,6-trichloronaphthalene, and among them, 1,3,5-trichlorobenzene and 1,2,4-trichlorobenzene are preferable. Examples of the active hydrogen-containing halogenated aromatic compound include halogenated aromatic compounds having functional groups such as amino group, mercapto group, and hydroxyl group. Specific examples include 2,5-dichloroaniline, 2,4-dichloroaniline, 2,3-dichloroaniline, 2,4,6-trichloroaniline, 2,2′-diamino-4,4′-dichlorodiphenyl ether, 2 , 4′-diamino-2 ′, 4-dichlorodiphenyl ether, and the like. Examples of the halogenated aromatic nitro compound include 2,4-dinitrochlorobenzene, 2,5-dichloronitrobenzene, 2-nitro-4,4′-dichlorodiphenyl ether, and 3,3′-dinitro-4,4′-. Examples include dichlorodiphenyl sulfone, 2,5-dichloro-2-nitropyridine, 2-chloro-3,5-dinitropyridine, and the like.

(13) Polymerization stabilizer In the production of the PAS of the present invention, a polymerization stabilizer can be used in order to stabilize the polymerization reaction system and prevent side reactions. The polymerization stabilizer contributes to stabilization of the polymerization reaction system and suppresses undesirable side reactions. One measure of the side reaction is the generation of thiophenol, and the addition of a polymerization stabilizer can suppress the generation of thiophenol. Specific examples of the polymerization stabilizer include compounds such as alkali metal hydroxides, alkali metal carbonates, alkaline earth metal hydroxides, and alkaline earth metal carbonates. Among these, alkali metal hydroxides such as sodium hydroxide, potassium hydroxide, and lithium hydroxide are preferable. Since the aforementioned organic carboxylic acid metal salt also acts as a polymerization stabilizer, it is one of the polymerization stabilizers used in the present invention.

  These polymerization stabilizers can be used alone or in combination of two or more. The polymerization stabilizer is usually 0.01 to 0.2 mol, preferably 0.03 to 0.1 mol with respect to 1 mol of the sulfur component of the alkali metal sulfide in the reaction system before the start of the polymerization reaction. It is desirable to use it. If this ratio is small, the stabilizing effect may be insufficient. Conversely, if it is too large, it tends to be economically disadvantageous or the polymer yield tends to decrease. In addition, when a part of alkali metal sulfide decomposes | disassembles at the time of reaction and hydrogen sulfide generate | occur | produces, the alkali metal hydroxide produced | generated as a result can also become a polymerization stabilizer.

(14) Polymerization step In the polyarylene sulfide production method of the present invention, the alkali metal sulfide slurry obtained by the above method is contacted with a dihalogenated aromatic compound in an organic polar solvent to polymerize the polyarylene sulfide. In the production, after starting the polymerization reaction, a step of carrying out the reaction from 200 ° C. to 260 ° C. at an average heating rate of 0.1 ° C./min or more (polymerization step A), and then a step of continuing the reaction at 250 ° C. or more ( It is desirable to include a polymerization step B). In the present invention, the polymerization of PAS is carried out by a method including at least a polymerization step A (hereinafter abbreviated as step A) and a polymerization step B (hereinafter abbreviated as step B). It is possible to obtain a polyarylene sulfide having a high melt viscosity at a high temperature. Hereinafter, step A and step B will be described in detail.

<Step A> In the present invention, when the alkali metal sulfide slurry is polymerized by contacting with a dihalogenated aromatic compound in an organic polar solvent, the reaction from 200 ° C. to 260 ° C. is carried out after the polymerization reaction is started. It is desirable to perform the process A performed at 0.1 degree-C / min or more. The average rate of temperature increase is the time m required to raise the temperature section (provided that t2 <t1) from a certain temperature t2 (° C.) to a certain temperature t1 (° C.). From (minutes), the following formula
Average heating rate (° C./min)=[t 1 (° C.) − T 2 (° C.)] / M (min)
Is the average speed calculated by Therefore, if it is within the range of the above average heating rate, it is not always necessary to have a constant rate, there may be a constant temperature section, and there is no problem even if the temperature is raised in multiple stages, and the essence of the present invention is impaired. As long as there is not, there may be a section which becomes a negative temperature rising rate temporarily.

  The average rate of temperature rise is preferably 0.1 ° C./min to 2.0 ° C./min, and more preferably 0.5 ° C./min to 1.5 ° C./min. If the average heating rate is too low, it tends to be difficult to increase the degree of polymerization effective for obtaining high toughness. If the average heating rate is too high, it may be difficult to control the reaction, and more energy tends to be required to raise the temperature. In addition, when a violent reaction occurs at the initial stage of the reaction, it tends to be preferable to carry out the reaction by a method in which the reaction is carried out to some extent at 240 ° C. or lower and then heated to a temperature exceeding 240 ° C.

  Step A is also preferably performed in the presence of at least one catalyst compound selected from organic carboxylic acid metal salts, aliphatic cyclic amine compounds, N-heteroaromatic compounds, and organic sulfoxide compounds.

  The amount of water in the reaction system in step A is the sulfur component in the reaction system at the start of the reaction, that is, when the conversion rate of the dihalogenated aromatic compound (hereinafter sometimes abbreviated as DHA) charged to the reaction system is zero. It is preferable that it is 0.05 mol or more and less than 0.8 mol per mol, 0.1-0.75 mol is preferable and 0.1-0.7 mol is more preferable. Furthermore, when the production of PAS is carried out under conditions with a small amount of polymerization solvent, the water content is preferably 0.1 to 0.7 mol, more preferably 0.1 to 0.6 mol, and 0.15 to 0.5 mol. Even more preferable. When the amount is too small, the polymerization reaction tends to hardly proceed, and when the amount is too large, the reaction promoting effect by the catalyst compound tends to be difficult to be exhibited. Therefore, when the components other than the alkali metal sulfide slurry according to the present invention contain water, it is preferable to dehydrate the components before the reaction to adjust the water content in the reaction system. Further, when the amount of water in the reaction system is small, it is preferable to add water preferably within the above range of water content. The DHA conversion rate is a value calculated by the following equation. The remaining amount of DHA can be usually determined by gas chromatography.

(A) When dihalogenated aromatic compound is added excessively in a molar ratio with respect to the alkali metal sulfide Conversion rate = [[DHA charge (mol) -DHA remaining amount (mol)] / [DHA charge (mol) −DHA excess (mole)]] × 100%
(B) In cases other than the above (a) Conversion rate = [[DHA charge (mol) −DHA remaining amount (mol)] / [DHA charge (mol)]] × 100%

  The amount of the organic polar solvent used as the polymerization solvent in Step A can be exemplified by the range of 0.2 to 15 moles per mole of sulfur component in the reaction system, but preferably per mole of sulfur component in the reaction system. 1.0 to 4.0 mol, more preferably 1.0 to 3.5 mol, and even more preferably 1.5 to 3.2 mol can be exemplified as a preferable range, and a significant improvement in polymer productivity is desired. Is preferably 1.5 to 2.7 mol, and 1.5 to 2.6 mol can be exemplified as a particularly preferable range. Generally, it is economically advantageous to use a small amount of polymerization solvent because the amount of polymer per unit volume increases.However, if the amount is too small, an undesirable reaction tends to occur, and if it is too large, the degree of polymerization tends to be difficult to increase. Yes, it may be economically disadvantageous. Further, if it is too much or too little, the time required for the reaction tends to become long, which may be disadvantageous economically.

  Furthermore, the reaction in the step A is such that the conversion rate of the dihalogenated aromatic compound at the end of the step A is 60 mol% or more, preferably 70% or more, more preferably 80% or more, and further preferably 90% or more. It is desirable to carry out this process, and this tends to make it easy to obtain a high polymerization degree PAS suitable for high toughness.

  <Step B> In the present invention, when the alkali metal sulfide slurry is polymerized by bringing it into contact with a dihalogenated aromatic compound in an organic polar solvent, the step B is continued after the step A at 250 ° C. or higher. desirable. It is preferable to perform the process B at 255 to 280 degreeC, and 260 to 280 degreeC is more preferable. When the temperature is less than 250 ° C., the reaction rate is relatively slow, and it is difficult to obtain a high viscosity PAS in a short time. On the other hand, when the temperature exceeds 300 ° C., the generated polymer component tends to be decomposed and the solvent tends to be deteriorated. Further, the reactor internal pressure tends to increase, and the reactor has a higher pressure resistance. Since a container may be required, it may be undesirable from an economic and safety standpoint.

  The reaction in Step B may be either a one-step reaction performed at a constant temperature, a multi-step reaction in which the temperature is raised stepwise, or a reaction in which the temperature is continuously changed. In addition, the reaction time in Step B depends on the type and amount of the raw material used, or the reaction temperature, and thus cannot be specified unconditionally. In addition, it is economically disadvantageous after 40 hours. The reaction time of the preferred step B can be exemplified as 0.5 to 10 hours. However, in the method of the present invention, a highly hydrous PAS can be obtained in a short time compared to the prior art because a low water content alkali metal sulfide having excellent reactivity is used. Therefore, the desired high viscosity PAS can be obtained in 0.5 to 5 hours, and further in 0.5 to 3 hours.

  The preferred reaction time of step B is as described above, but the ratio of the time ma (minute) required for step A to the time mb (minute) required for step B, ma / mb is preferably less than 1.5. Less than 0.0 is more preferable. By setting Ta / Tb in this way, a PAS having a high degree of polymerization tends to be easily obtained even under conditions where the total time of the process A and the process B is short.

  In Step B, at least part of the amount of water in the reaction system is 0.8 to 5.0 mol, preferably 0.8 to 2.0 mol, more preferably 0, per mol of sulfur component in the reaction system. It is desirable to carry out the reaction by adjusting the amount to 85 to 1.8 mol, which is particularly effective for efficiently obtaining a PAS having a high degree of polymerization and a high viscosity. If the amount of water is below the above range, a longer reaction time tends to be required to obtain the desired high degree of polymerization PAS. A reactor having pressure resistance may be required. Although there is no restriction | limiting in particular in the method at the time of adjusting the moisture content in a polymerization system, For example, the method of press-fitting a deficient water in a reaction system can be illustrated.

  It is preferable to perform the process B continuously from the process A, and the process A and the process B may be performed in the same reactor, or the reaction mixture in the process A is transferred to a different reactor and the process B is performed. Also good.

  The amount of the organic polar solvent used as the polymerization solvent in Step B can be exemplified by the range of 0.2 to 15 moles per mole of sulfur component in the reaction system, but preferably per mole of sulfur component in the reaction system. 1.0 to 4.0 mol, more preferably 1.0 to 3.5 mol, and even more preferably 1.5 to 3.2 mol can be exemplified as a preferable range, and a significant improvement in polymer productivity is desired. Is preferably 1.5 to 2.7 mol, and 1.5 to 2.6 mol can be exemplified as a particularly preferable range. Generally, it is economically advantageous to use a small amount of polymerization solvent because the amount of polymer per unit volume increases.However, if the amount is too small, an undesirable reaction tends to occur, and if it is too large, the degree of polymerization tends to be difficult to increase. Yes, it may be economically disadvantageous. Further, if it is too much or too little, the time required for the reaction tends to become long, which may be disadvantageous economically.

  In the polymerization of the present invention, known polymerization methods such as a batch method and a continuous method can be employed. Further, the atmosphere during polymerization is preferably a non-oxidizing atmosphere, preferably carried out in an inert gas atmosphere such as nitrogen, helium, and argon, and nitrogen is particularly preferred from the viewpoint of economy and ease of handling. . The reaction pressure is not particularly limited because it cannot be defined unconditionally depending on the type and amount of the raw material and solvent used, or the reaction temperature.

  In order to obtain a high degree of polymerization PAS in a shorter time, it is preferable to carry out at least a part of the entire polymerization step in the presence of the polymerization aid described above. Although there is no restriction | limiting in particular in the addition time of a polymerization auxiliary agent, it adds at any time before the start of preparation of a low hydrous alkali metal sulfide, the time of the start of process A, the process A, the start of process B, and the process B Alternatively, it may be added in a plurality of times. However, if at least Step B is performed in the presence of a polymerization aid, a high degree of polymerization PAS can be easily obtained in a short time. The polymerization aid may be added in any form, such as an anhydride, hydrate, aqueous solution or mixture with an organic polar solvent. However, when the polymerization aid to be added contains water and at the start of step A Or when adding in the middle of the process A, it is preferable that the water content per 1 mol of sulfur components in the reaction system at the stage where the addition of the polymerization aid is completed is 0.05 mol or more and less than 0.8 mol.

  In order to obtain a PAS having a high degree of polymerization, it is preferable to continue the polymerization by adding an alkali metal hydroxide during the polymerization. Although this effect is not clear, it is presumed that there is a tendency to stabilize the polymerization reaction particularly when the conversion rate of the dihalogenated aromatic compound is high, and this facilitates a high degree of polymerization reaction. The addition time of the alkali metal hydroxide is not particularly limited as long as it is in the middle of the polymerization, but when the preferred addition time is indicated by the conversion rate of the dihalogenated aromatic compound, the lower limit of the conversion rate is 60% or more, preferably 70%. Above, more preferably 80% or more, still more preferably 90% or more, and the upper limit is 98% or less, preferably 95% or less. When the addition time is less than the preferable lower limit, the by-product tends to increase, and when it exceeds the upper limit, the effect tends to be difficult to obtain. Among the alkali metal hydroxides, lithium hydroxide, sodium hydroxide and potassium hydroxide are preferable, and sodium hydroxide is particularly preferable. There is no particular limitation on the form of the alkali metal hydroxide, and it can be used in any form of anhydride, hydrate, and aqueous mixture, but the viewpoint of easy availability and handling of the aqueous mixture. Is preferable. Moreover, as a method of adding an alkali metal hydroxide as an aqueous mixture, a method of press-fitting into a reaction system can be exemplified.

  In addition, after adding an alkali metal hydroxide in the middle of polymerization, the alkali metal hydroxide added by the action of a compound other than the alkali metal hydroxide already present in the reaction system is converted into another compound May be used in the same manner as the alkali metal hydroxide after conversion. That is, there is no problem even if the converted compound is added as an alkali metal hydroxide during the polymerization.

  The amount of alkali metal hydroxide added during the polymerization is not particularly limited, but is preferably 0.01 to 0.2 mol, preferably 1 to 0.2 mol, based on 1 mol of the sulfur component of the alkali metal sulfide in the reaction system before the start of the polymerization reaction. It is desirable to use at a ratio of 0.02 to 0.15 mol. If this ratio is small, the effect may be difficult to obtain, and if it is too large, it is difficult to obtain a further effect, which may be economically disadvantageous.

  When the alkali metal hydroxide is added in a form containing water, such as a hydrate and an aqueous mixture, the amount of this water is optional, but in this case, the amount of water in the reaction system after adding the alkali metal hydroxide. Should be noted, the amount of water contained in the alkali metal hydroxide should be noted. That is, as described above, there is no limitation on the addition time of the alkali metal hydroxide as long as it is in the course of polymerization, and there is no problem even if it is carried out at any stage of Step A and Step B, but the alkali metal hydroxide was added. When the amount of water in the reaction system changes later, it is desirable that the amount of water in the reaction system after the addition becomes a preferable amount of water in each of step A and step B.

(15) Polymer Recovery In the production of the PAS of the present invention, PAS is recovered from a solid material containing a PAS component and a solvent obtained in the polymerization step after the polymerization step. As a recovery method, for example, a flash method, that is, a polymerization reaction product is flashed from a high-temperature and high-pressure (normally 250 ° C. or higher, 0.8 MPa or higher) state to an atmosphere of normal pressure or reduced pressure, and the polymer is powdered simultaneously with solvent recovery. The polymerization reaction product is gradually cooled from the high temperature and high pressure state to recover and the polymerization reaction product is gradually cooled from the high temperature and high pressure state to precipitate the PAS component in the reaction system, and 70 ° C. As mentioned above, the method of collect | recovering the solid containing a PAS component by filtering off preferably in the state of 100 degreeC or more etc. are mentioned. Here, the state where the polymer component is precipitated is a state where at least 60% or more of the generated polymer component is not melted and dissolved in the polymerization solvent. More specifically, when the solid component in the polymer obtained by rapidly cooling the reaction system in a certain state to 100 ° C. or less was recovered by 80-mesh sieving, all of the charged low water content alkali metal sulfide was converted to PAS. Based on the assumed weight (theoretical amount), it can be recovered in a yield of 60% or more. Also, when the molar amount of the sulfur component of the alkali metal sulfide present in the system before the start of the polymerization reaction is larger than the molar amount of the dihalogenated aromatic compound, it cannot be converted into PAS. In some cases, the amount of alkali metal sulfide present in the system before the start of the polymerization reaction is considered as a reference. Further, as a preferable mode when the polymerization reaction product is gradually cooled from the high temperature and high pressure state, when the polymer component is cooled at an average rate of about 1 ° C./min from a state where at least 60% of the polymer component is melted in the polymerization solvent. An example is an embodiment in which the average cooling rate at least at Ts ± 10 ° C. is 0.01 to 2 ° C./min with respect to the temperature Ts (° C.) at which the polymer component is deposited. Here, the average cooling rate is the following from the time m (minutes) required to cool the temperature section (where t1> t2) from a certain temperature t1 (° C.) to a certain temperature t2 (° C.). Formula Average cooling rate (° C / min) = [t1 (° C)-t2 (° C)] / m (min)
Is the average speed calculated by Therefore, if it is in the range of the cooling rate mentioned above, it does not necessarily need to be a constant rate, there may exist a constant temperature area, and it does not interfere even if it cools by multistage. In addition, as said Ts (degreeC), about 180 degreeC to about 250 degreeC can be illustrated in the preferable usage-amount range of the organic polar solvent mentioned above, for example.

  The product containing the solid PAS thus obtained is preferably washed with an organic solvent and / or water.

  The following method can be illustrated as a specific method when the product containing solid PAS is washed with an organic solvent. That is, the organic solvent used for washing is not particularly limited as long as it does not have an action of decomposing PAS. For example, nitrogen-containing polar solvents such as N-methyl-2-pyrrolidone, dimethylformamide, dimethylacetamide, Sulfoxide and sulfone solvents such as dimethyl sulfoxide and dimethyl sulfone, ketone solvents such as acetone, methyl ethyl ketone, diethyl ketone and acetophenone, ether solvents such as dimethyl ether, dipropyl ether and tetrahydrofuran, chloroform, methylene chloride, trichloroethylene and ethylene chloride , Halogen solvents such as dichloroethane, tetrachloroethane, chlorobenzene, methanol, ethanol, propanol, butanol, pentanol, ethylene glycol, propylene group Call, phenol, cresol, alcohol phenol based solvents such as polyethylene glycol, benzene, toluene, and aromatic hydrocarbon solvents such as xylene. Among these organic solvents, use of N-methyl-2-pyrrolidone, acetone, dimethylformamide, chloroform and the like is preferable, and N-methyl-2-pyrrolidone and / or acetone is more preferable. These organic solvents can be used as one kind or a mixture of two or more kinds.

  As a method of washing with an organic solvent, there is a method of immersing PAS in an organic solvent, and it is possible to appropriately stir or heat as necessary.

  There is no restriction | limiting in particular about the washing | cleaning temperature at the time of wash | cleaning PAS with an organic solvent, Arbitrary temperature of about normal temperature-about 300 degreeC can be selected. Although the cleaning efficiency tends to increase as the cleaning temperature increases, a sufficient effect is usually obtained at a cleaning temperature of room temperature to 150 ° C.

  The ratio of PAS and organic solvent is preferably higher in organic solvent, but usually a bath ratio of 300 g or less of PAS per 1 liter of organic solvent is selected.

  In addition, when a product containing solid PAS in a slurry state containing granular PAS is obtained by using a method in which the polymerization reaction product is gradually cooled and recovered from a high-temperature and high-pressure state as a recovery method, Before the washing, it is preferable to filter the slurry and then wash with an organic solvent. By following such a procedure, a higher cleaning effect can often be obtained when the same amount of organic solvent is used. In addition, although there is no restriction | limiting in particular in the filtering method, Filtering by a sieve etc., filtering by centrifugation, filtering using a filter cloth, etc. can be illustrated.

  Moreover, in order to remove a residual organic solvent and an ionic impurity from the product containing solid PAS, it is preferable to wash several times with water.

  As a method for washing PAS with water, there is a method of immersing PAS in water, and it is possible to appropriately stir or heat as necessary.

  The washing temperature when washing PAS with water is preferably 20 ° C to 220 ° C, more preferably 50 ° C to 200 ° C. If it is less than 20 ° C., it is difficult to remove by-products, and if it exceeds 220 ° C., the pressure becomes high, which is not preferable for safety.

  The water used in the water washing is preferably distilled water or deionized water, but if necessary, formic acid, acetic acid, propionic acid, butyric acid, chloroacetic acid, dichloroacetic acid, acrylic acid, crotonic acid, benzoic acid, salicylic acid, Organic acidic compounds such as oxalic acid, malonic acid, succinic acid, phthalic acid, fumaric acid and their alkali metal salts, alkaline earth metal salts, inorganic acidic compounds such as sulfuric acid, phosphoric acid, hydrochloric acid, carbonic acid, silicic acid, ammonium ions, etc. An aqueous solution containing may be used.

  The operation of the hot water treatment for washing with water of 100 ° C. or higher is usually performed by charging a predetermined amount of water with a predetermined amount of PAS, and heating and stirring at normal pressure or in a pressure vessel. The ratio of PAS and water is preferably as much as possible, but usually a bath ratio of 200 g or less of PAS is selected for 1 liter of water.

(16) Other post-treatments The PAS thus obtained is dried under normal pressure and / or under reduced pressure. The drying temperature is preferably in the range of 120 to 280 ° C, more preferably in the range of 140 to 250 ° C. The drying atmosphere may be any of an inert atmosphere such as nitrogen, helium and reduced pressure, an oxidizing atmosphere such as oxygen and air, and a mixed atmosphere of air and nitrogen, preferably under reduced pressure, particularly under normal pressure. It is preferable to dry again under reduced pressure after drying to remove moisture and the like. The drying time is preferably 0.5 to 50 hours, preferably 1 to 30 hours, and more preferably 1 to 20 hours.

  The PAS obtained in the present invention can be treated at a temperature of 130 to 260 ° C. in an oxygen-containing atmosphere in order to remove volatile components or to increase the cross-linking molecular weight.

  When carrying out dry heat treatment for the purpose of suppressing cross-linking high molecular weight and removing volatile matter, the temperature is preferably from 130 to 250 ° C, more preferably from 160 to 250 ° C. Further, it is desirable that the oxygen concentration is less than 2% by volume, more preferably less than 1% by volume. Drying under reduced pressure is also a preferred method. The treatment time is preferably 0.5 to 50 hours, more preferably 1 to 20 hours, and still more preferably 1 to 10 hours.

  When the dry heat treatment is performed for the purpose of increasing the cross-linking molecular weight, the temperature is preferably 160 to 260 ° C, more preferably 170 to 250 ° C. Further, it is desirable that the oxygen concentration is 2% by volume or more, more preferably 8% by volume or more. The treatment time is preferably 1 to 100 hours, more preferably 2 to 50 hours, and even more preferably 3 to 25 hours.

  The heat treatment apparatus may be a normal hot air dryer or a heating apparatus with a rotary blade or a stirring blade. However, for efficient and more uniform treatment, a heating device with a rotary blade or a stirring blade is used. Is more preferable.

(16) Generated PAS
-PAS obtained by the present invention is excellent in heat resistance, chemical resistance, flame retardancy, electrical properties and mechanical properties, and not only for injection molding, injection compression molding and blow molding, but also by extrusion molding, It can be formed into extruded products such as films, fibers and pipes. In addition, since the low water content alkali metal sulfide of the present invention has a small amount of metal elution from the metal reactor in its production, the PAS obtained using this has high whiteness only for applications requiring high whiteness. In addition, it can be suitably used for applications that require coloring. In addition, whiteness can be represented by the L value which measured the granular polymer dried using the color measuring machine here, for example. For wider application to various uses using PAS, the whiteness of PAS is preferably 55 or more, more preferably 60 or more in terms of L value.

  Examples of the use of the resin composition of the present invention include sensors, LED lamps, connectors, sockets, resistors, relay cases, switches, coil bobbins, capacitors, variable capacitor cases, optical pickups, oscillators, various terminal boards, transformers, Electricity represented by plugs, printed circuit boards, tuners, speakers, microphones, headphones, small motors, magnetic head bases, power modules, semiconductors, liquid crystals, FDD carriages, FDD chassis, motor brush holders, parabolic antennas, computer-related parts, etc. Electronic parts: VTR parts, TV parts, irons, hair dryers, rice cooker parts, microwave oven parts, acoustic parts, audio equipment parts such as audio / laser discs (registered trademark) / compact discs, lighting parts, refrigerators Products, air conditioner parts, typewriter parts, homes such as word processor parts, office electrical product parts; office computer related parts, telephone equipment related parts, facsimile related parts, copying machine related parts, cleaning jigs, motor parts, Machine-related parts typified by lighters and typewriters: Optical equipment typified by microscopes, binoculars, cameras, watches, etc., precision machine-related parts; water taps, mixing faucets, pump parts, pipe joints, water volume control valves , Water supply parts such as relief valves, hot water temperature sensors, water volume sensors, water meter housings; valve alternator terminals, alternator connectors, IC regulators, light detent potentiometer bases, various valves such as exhaust gas valves, fuel-related and exhaust System / intake system pipes, Ar intake nozzle snorkel, intake manifold, fuel pump, engine coolant joint, carburetor main body, carburetor spacer, exhaust gas sensor, coolant sensor, oil temperature sensor, throttle position sensor, crankshaft position sensor, air flow meter, brake pad Wear sensor, thermostat base for air conditioner, heating hot air flow control valve, brush holder for radiator motor, water pump impeller, turbine vane, wiper motor related parts, distributor, starter switch, starter relay, transmission wire harness, window washer Nozzle, air conditioner panel switch board, fuel-related electromagnetic valve coil , Fuse connector, horn terminal, electrical component insulation plate, step motor rotor, lamp socket, lamp reflector, lamp housing, brake piston, solenoid bobbin, engine oil filter, fuel tank, ignition device case, vehicle speed sensor, cable liner, etc. Examples include automobile / vehicle-related parts and other various uses.

  As a method for producing a PPS film using the PAS obtained according to the present invention, a known melt film-forming method can be employed. For example, after melting PAS in a single-axis or biaxial extrusion period, Manufactured by a method of creating a film by cooling on an extrusion cooling drum, or a biaxial stretching method in which the film thus produced is stretched vertically and horizontally by a roller-type longitudinal stretching apparatus and a transverse stretching apparatus called a tenter. However, the present invention is not limited to this.

  The PAS film obtained in this way has excellent mechanical properties, electrical properties, and heat resistance, and is suitably used for various applications such as dielectric films for film capacitors and chip capacitors, and films for mold release. can do.

  As a method for producing a PAS fiber using the PAS obtained by the present invention, a known melt spinning method can be applied. For example, kneading while supplying a raw material PAS chip to a single-screw or twin-screw extruder Then, a method of extruding from a spinneret through a polymer stream line changer installed at the tip of the extruder, a filtration layer, etc., cooling, stretching, heat setting, etc. can be adopted, but it is particularly limited to this. It is not something.

  The PAS monofilament or short fiber thus obtained can be suitably used for various applications such as a papermaking dryer campus, a net conveyor, and a bag filter.

  Hereinafter, the method of the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. Various measurement methods are as follows.

[Residual rate of alkali metal sulfide in reactor (1)]
According to the present invention, it is possible to improve the fluidity of the low water content alkali metal sulfide, whereby the alkali metal sulfide slurry in the reactor (1) after being transferred from the reactor (1) to the reactor (2). The residual amount of is also reduced. In order to evaluate this, the alkali metal sulfide slurry prepared in the production process of the alkali metal sulfide slurry was transferred from the reactor (1) to the reactor (2) and then remained in the reactor (1). The residual ratio of the metal sulfide slurry was calculated by the following formula.
Residual rate (wt%) = [(Sample introduced to reactor (1) (g) −Dewatered amount (g) −Transfer amount (g)) / [Sample introduced to reactor (1) (g) − Drainage amount (g)] × 100

[Polymer yield]
The yield of PAS was defined as the ratio of the yield of PAS to the weight (theoretical amount) assuming that all sulfur components in the reactor before polymerization were converted to PAS. If the sulfur component is charged in excess of the dihalogenated aromatic compound, it may not be all converted to PAS, but even in that case, the amount of the sulfur component is considered as a reference.

[Polymer melt viscosity]
The melt viscosity of the polymer was measured as a melt flow rate (unit: g / 10 min) using a Toyo Seiki melt indexer F-B01. The measurement was performed using an orifice having a hole diameter of 2.096 mm and a length of 8.00 mm under conditions of a temperature of 315.5 ° C. and a load of 5 kg. The amount of sample charged into the melt indexer is about 7 g. When the sample is put into the apparatus and the piston is inserted after 1 minute, and when the piston is further loaded after 4 minutes, about 2.5 g of polymer flows out. This was done by measuring the time.

[Example 1]
First, low hydrous sodium sulfide was prepared using a SUS316 1 liter autoclave with a stirrer.

<Preparation of low hydrous sodium sulfide (step 1)>
A 1 liter autoclave with a stirrer made of SUS316 having a bottom plug valve (hereinafter sometimes abbreviated as “reactor (1)”) 116.9 g of a sodium hydrosulfide aqueous solution having a concentration of 48 wt% (1.0 mol in terms of sodium hydrosulfide). ), 193.8 g (1.05 mol in terms of sodium hydroxide) of an aqueous solution of sodium hydroxide having a concentration of 21.7 wt% obtained by dissolving 96% sodium hydroxide in 150 g of water, 119.0 g (1.2 mol) of NMP, and anhydrous Sodium acetate 21.3 g (0.26 mol) was charged at room temperature. Assuming that all of the sodium hydrosulfide charged is converted to sodium sulfide, the amount of water relative to 1 mol of sulfur component of sodium sulfide is 12.7 mol (228.8 g), and the amount of NMP is 1.2 mol. there were.

  A rectifying column containing a filler is attached to the upper part of the reactor (1) through a valve, and gradually heated to 205 ° C., which is the boiling point of NMP, over about 1.5 hours while stirring through nitrogen at normal pressure. Then, 205 g of a distillate was obtained. When this distillate was analyzed by gas chromatography, the composition of the distillate was 203.5 g of water and 1.5 g of NMP. At this stage, 25.3 g (1.40 mol) of water was contained in the reaction system. It was found that 117.5 g (1.18 mol) of NMP remained.

<Preparation of low hydrous sodium sulfide (Step 2)>
Subsequently, heating was continued, and the temperature was gradually raised to about 260 ° C. over about 1.5 hours to obtain 95.8 g of a distillate. When this distillate was analyzed by gas chromatography, the composition of the distillate was 18.1 g of water and 77.7 g of NMP. Accordingly, 7.2 g (0.40 mol) of water and 39.7 g (0.40 mol) of NMP remained in the reaction system, and 0.40 mol of water and 0.40 mol per mol of sulfur component. It can be seen that a low hydrous sodium sulfide containing moles of NMP could be prepared. The hydrogen sulfide scattered from the reaction system through the steps 1 and 2 was 0.006 mol.

<Preparation of sodium sulfide slurry>
After the completion of step 2, the valve on the top of the reactor (1) was closed, and then cooled to about 230 ° C. Thereafter, 29.7 g (0.30 mol) of NMP was added to the pressure vessel connected in advance to the inside of the reactor (1) via a pressure valve at the top of the reactor (1), and then replaced with nitrogen. And NMP was added to the reactor (1) under pressurized conditions. The composition in the reactor (1) at this stage was 0.40 mol of water and 0.70 mol of NMP per mol of sulfur component.

<Transfer of sodium sulfide slurry>
After completion of the addition of NMP, the upper valve of the reactor (1) is closed, and a 500 mL glass container prepared in advance and the bottom plug valve of the reactor (1) are connected by piping, so that the temperature of the reactor (1) reaches 215 ° C. When reached, the bottom plug valve was opened and the contents of the reactor (1) were transferred to a 500 mL glass container. The transfer time, which was the time from the start of opening of the bottom plug valve to the end of the liquid drop from the reactor (1), was 10 seconds. Moreover, the residual rate in the reactor (1) calculated from the transfer amount to a 500 mL glass container was 8.6 wt%.

[Comparative Example 1]
Preparation of low hydrous sodium sulfide in the reactor (1) in the same manner as in Example 1, and transfer from the reactor (1) to a 500 mL glass container without adding NMP to the obtained low hydrous sodium sulfide Went. The transfer time was 90 seconds, and the residual rate in the reactor (1) was 40.7%.

  From the results of Example 1 and Comparative Example 1, it was found that the transfer time was shortened and the residual rate in the reactor (1) could be reduced by improving the fluidity of the prepared low hydrous sodium sulfide.

[Example 2]
Here, the result of trying to synthesize PPS using the sodium sulfide slurry obtained in Example 1 is shown.

  In order to transfer the sodium sulfide slurry prepared in the reactor (1) of Example 1 to the reactor (2) different from the reactor (1), the bottom plug valve of the reactor (1) and the reactor (2) A pipe for connecting the two was previously installed.

  After completing the preparation of the sodium sulfide slurry, the bottom plug valve of the reactor (1) was opened when the temperature reached 185 ° C., and the sodium sulfide slurry was transferred to the reactor (2). The temperature of the reactor (2) at the start of the transfer was 185 ° C., and the residual rate in the reactor (1) calculated from the transferred amount to the reactor (2) was 8.1%.

<PPS polymerization>
Since there is a residue in the reactor (1), p-dichlorobenzene (p-DCB), NMP, and water added to the reactor (2) are removed from the sodium sulfide slurry transferred to the reactor (2). The amount added was determined according to the actual amount. As a precondition for determining the addition amount, it is assumed that the sodium sulfide slurry remaining in the reactor (1) and the reactor (2) has the same composition. That is, for example, when the residual rate in the reactor (1) is 10%, the sulfur component remaining in the reactor (1) is also 10% of the total sulfur component, and in the reactor (2), 90% of the total sulfur component. The amount of p-DCB, NMP, and water added is calculated assuming that% is transferred.

After completion of the transfer, the bottom plug valve was closed, and a pressure vessel connected to the inside of the reactor (2) via a pressure valve was attached to the top of the reactor (2), and the inside of the reactor (2) was sealed under nitrogen gas. Using a pressure vessel, 138.5 g (0.94 mol) of liquid p-DCB and 164.0 g (1.65 mol) of NMP were added into the reactor (2) by press-fitting with pressurized nitrogen. At this stage, the amount of water per mol of sulfur component in the reaction system was 0.40 mol, the amount of NMP was 2.5 mol, and the amount of DCB was 1.025 mol.
While stirring the contents of the reactor (2) at 400 rpm, the temperature was raised from 200 ° C. to 230 ° C. over 30 minutes, and then maintained at 230 ° C. for 50 minutes. Subsequently, the temperature of the reaction system was raised from 230 ° C. to 270 ° C. over 40 minutes. After reaching 270 ° C. for 10 minutes, 18.2 g (1.01 mol) of water was injected into the reaction system over 10 minutes. As a result, the amount of water per mole of sulfur component in the reaction system became 1.5 moles. After adding water, it was kept at 270 ° C. for 105 minutes. Then, after cooling from 270 ° C. to 250 ° C. over 15 minutes, it was cooled from 250 ° C. to 220 ° C. over 75 minutes, and further rapidly cooled to near room temperature, and the contents were taken out. The recovered content was 551 g.

<Polymer recovery>
The contents were diluted with 0.5 liters of NMP, stirred as a slurry at 85 ° C. for 30 minutes, and then filtered through an 80 mesh wire net to obtain a solid. The obtained solid was washed and filtered again with 0.5 liter of NMP. The obtained solid was washed again with 1 liter of water (70 ° C.) three times and filtered. Subsequently, 0.52 g of acetic acid and 1 liter of water (70 ° C.) were added to the obtained solid substance, followed by washing and filtration. Further, the obtained solid was again washed with 1 liter of water (70 ° C.) and filtered.

    The solid thus obtained was dried with hot air at 130 ° C. to obtain a dried polymer. The polymer yield was 89% and the polymer melt flow rate was 109 g / 10 min.

[Comparative Example 2]
Here, the result of an attempt to synthesize PPS in the same manner as in Example 2 using sodium sulfide obtained in Comparative Example 1 is shown.

  As in Example 2, the reactor (1) was installed in the reactor (2), and the residual ratio in the reactor (1) calculated from the amount transferred from the reactor (1) to the reactor (2) was It was 41.2%.

<PPS polymerization>
As in Example 2, the amounts of p-DCB, NMP, and water added to the reactor (2) were determined in accordance with the actual amount of sodium sulfide transferred to the reactor (2).

To the reactor (2), 88.6 g (0.60 mol) of p-DCB and 122.4 g (1.23 mol) of NMP were added into the reactor (2) by press-fitting with pressurized nitrogen. At this stage, the amount of water per mol of sulfur component in the reaction system was 0.40 mol, the amount of NMP was 2.5 mol, and the amount of DCB was 1.025 mol.
While stirring the contents of the reactor (2) at 400 rpm, the temperature was raised from 200 ° C. to 230 ° C. over 30 minutes, and then maintained at 230 ° C. for 50 minutes. Subsequently, the temperature of the reaction system was raised from 230 ° C. to 270 ° C. over 40 minutes. After reaching 270 ° C. and holding for 10 minutes, 11.6 g (0.65 mol) of water was injected into the reaction system over 10 minutes. As a result, the amount of water per mole of sulfur component in the reaction system became 1.5 moles. After adding water, it was kept at 270 ° C. for 105 minutes. Then, after cooling from 270 ° C. to 250 ° C. over 15 minutes, it was cooled from 250 ° C. to 220 ° C. over 75 minutes, and further rapidly cooled to near room temperature, and the contents were taken out. The collected content was 353 g.

<Polymer recovery>
The contents were diluted with 0.5 liters of NMP, stirred as a slurry at 85 ° C. for 30 minutes, and then filtered through an 80 mesh wire net to obtain a solid. The obtained solid was washed and filtered again with 0.5 liter of NMP. The obtained solid was washed again with 1 liter of water (70 ° C.) three times and filtered. Subsequently, 0.52 g of acetic acid and 1 liter of water (70 ° C.) were added to the obtained solid substance, followed by washing and filtration. Further, the obtained solid was again washed with 1 liter of water (70 ° C.) and filtered.

    The solid thus obtained was dried with hot air at 130 ° C. to obtain a dried polymer. The polymer yield was 75% and the polymer melt flow rate was 423 g / 10 min.

  As is clear from the above results, polymerization was performed using a sodium sulfide slurry prepared by adding a small amount of NMP to low hydrous sodium sulfide before transfer from the reactor (1) to the reactor (2). Then, since the transfer can be performed efficiently, the production amount per unit is high. Furthermore, it was found that high yields can be achieved while at the same time high-viscosity PPS can be obtained. On the other hand, in Comparative Example 2 in which transfer was performed without adding NMP to low hydrous sodium sulfide and polymerization was performed using the transferred product, the production amount per unit was low. Furthermore, the yield was low and only low viscosity PPS was obtained. This is because the low hydrous alkali metal sulfide has low fluidity and is difficult to transport in a uniform state, and is composed of the residue in the reactor (1) and the transported material in the reactor (2). Since the ratios were different, it was speculated that the balance during polymerization was lost, resulting in poor polymerization.

Claims (7)

(B) A method for producing a slurry containing an alkali metal sulfide, wherein (a) an organic polar solvent is added to the anhydrous alkali metal sulfide and / or the low hydrous alkali metal sulfide. 2. The alkali metal according to claim 1, wherein the low water content alkali metal sulfide is a low water content alkali metal sulfide containing less than 1.5 moles of water per mole of sulfur component of the alkali metal sulfide. A method for producing a slurry containing sulfide. At least (b) alkali metal sulfide, 0.8 to 10 moles of (c) organic amide solvent per mole of sulfur component of the alkali metal sulfide, and 0.8 to about 0.8 to 1 mole of sulfur component of the alkali metal sulfide. From the mixture containing 20 moles of (d) water, (c) the organic amide solvent and (d) water are removed, and the amount of water and the amount of organic amide solvent in the mixture are determined per mole of sulfur component of the alkali metal sulfide. A method for producing a slurry containing an alkali metal sulfide, wherein (a) an organic polar solvent is added to (b) a low hydrous alkali metal sulfide each adjusted to 0.05 mol or more and less than 0.8 mol. 4. The alkali according to any one of claims 1 to 3, wherein the amount of the (a) organic polar solvent added is 0.01 mol or more and 14.2 mol or less per mol of the sulfur component of the (b) alkali metal sulfide. A method for producing a slurry containing a metal sulfide. The method for producing a slurry containing an alkali metal sulfide according to any one of claims 1 to 4, wherein (a) an organic polar solvent is added to (b) the alkali metal sulfide at 180 ° C or higher. A slurry containing an alkali metal sulfide obtained by the production method according to any one of claims 1 to 5 and a dihalogenated aromatic compound are brought into contact with each other in an organic polar solvent for polymerization to produce a polyarylene sulfide. Method. After preparing the slurry containing an alkali metal sulfide by the production method according to any one of claims 1 to 5 in the reactor (1), the slurry containing the alkali metal sulfide is transferred to the reactor (2), and dihalogen The method for producing a polyarylene sulfide according to claim 6, wherein the polyarylene sulfide is brought into contact with the fluorinated aromatic compound.