JP2008248154A - Method for producing polyarylene sulfide resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a slurry composition containing a solid anhydrous alkali metal sulfide in the presence of an aromatic polyhalogen compound, a hydrous alkali metal sulfide, and a compound having an aliphatic ring structure that can be ring-opened by hydrolysis. In the dehydration step, a method for producing a polyarylene sulfide resin having high productivity on an industrial scale by suppressing the distillation of the aromatic polyhalogen compound to the outside of the reaction vessel and reducing the time of the dehydration step. To provide.
A slurry-like composition containing a solid anhydrous alkali metal sulfide in the presence of an aromatic polyhalogen compound, a hydrous alkali metal sulfide, and a compound having an aliphatic ring structure that can be ring-opened by hydrolysis. During the dehydration step to be obtained, the vapor is cooled so that the temperature of the gas phase inside the reaction vessel is in a specific range in an open system, and the aromatic polyhalogen compound is refluxed to the liquid phase.
[Selection figure] None

Description

  The present invention relates to a highly efficient method for producing a polyarylene sulfide resin having a linear structure.

  Polyarylene sulfide resins represented by polyphenylene sulfide resins are excellent in heat resistance and chemical resistance, and are widely used in electrical and electronic parts, automobile parts, water heater parts, fibers, films and the like. In each of these uses, from the viewpoints of strength and moldability, in particular, a demand for a high molecular weight polyarylene sulfide resin is particularly high. The high molecular weight polyarylene sulfide resin can also be produced by synthesizing a low molecular weight polyarylene sulfide resin and then thermally oxidizing and crosslinking it. However, the method of increasing the molecular weight by thermal oxidation crosslinking as described above has a problem in terms of productivity because it takes a long time, and the melt viscosity becomes very high, so that melt molding is impossible. Therefore, an efficient method for producing a high molecular weight polyarylene sulfide resin is desired.

  Therefore, as an efficient method for producing such a high molecular weight polyarylene sulfide resin, for example, an aromatic polyhalogen compound, a hydrous alkali metal sulfide, and less than 1 mol of N-methyl per mol of the hydrous alkali metal sulfide. A method is known in which pyrrolidone is mixed and the mixture is azeotropically dehydrated to obtain a slurry-like composition containing fine-particle alkali metal sulfide, and then polymerized (see Patent Document 1).

  However, although the production method can suppress side reactions and has a low content of by-product impurities and can efficiently produce a high molecular weight polyarylene sulfide resin, in the step of dehydrating the hydrated alkali metal sulfide, As the dehydration reaction progressed, the dehydration efficiency decreased and the productivity decreased.

Japanese Patent No. 3637543

  The problem to be solved by the present invention includes a solid anhydrous alkali metal sulfide in the presence of an aromatic polyhalogen compound, a hydrous alkali metal sulfide, and a compound having an aliphatic cyclic structure that can be ring-opened by hydrolysis. In the dehydration step for obtaining a slurry-like composition, the distillation of aromatic polyhalogen compounds to the outside of the reaction vessel is suppressed, and the time for the dehydration step is shortened. The object is to provide a method for producing an arylene sulfide resin.

  As a result of diligent studies to solve the above problems, the present inventors have found that in the presence of an aromatic polyhalogen compound, a hydrous alkali metal sulfide, and a compound having an aliphatic cyclic structure that can be ring-opened by hydrolysis, During the dehydration process to obtain a slurry-like composition containing anhydrous alkali metal sulfide, the vapor is cooled so that the temperature of the gas phase inside the reaction vessel is in a specific range in an open system, and the aromatic polyhalogen By refluxing the compound to the liquid phase, distilling out of the reaction vessel is suppressed, and the time for the dehydration step is shortened, thereby producing a method for producing polyarylene sulfide resin having high productivity on an industrial scale. The headline and the present invention were completed.

That is, the present invention includes the following step 1 and step 2,
Step 1: An aromatic polyhalogen compound (A), a hydrous alkali metal sulfide (B), and an aliphatic cyclic ring that can be opened by hydrolysis of less than 1 mole with respect to 1 mole of the hydrous alkali metal sulfide (B). The vapor of the mixed liquid of the compound (C) having a structure is cooled so that the temperature of the gas phase inside the reaction vessel is in the range of 90 ° C. to 160 ° C. in an open system, and the aromatic polyhalogen compound (A) The solid alkali metal sulfide (b1), the alkali metal hydrosulfide (b2), and the alkali of the hydrolyzate of the compound (C) were obtained while refluxing the liquid phase into the liquid phase and distilling off the water to the outside of the reaction vessel. Producing a slurry containing a metal salt (c1),
Step 2: Next, in the presence of the slurry, the aromatic polyhalogen compound (A), the alkali metal hydrosulfide (b2), and the alkali metal salt (c1) of the hydrolyzate of the compound (C) are reacted. A step of polymerizing,
The present invention relates to a method for producing a polyarylene sulfide resin having an essential production process.

  According to the present invention, a slurry-like composition containing a solid anhydrous alkali metal sulfide in the presence of an aromatic polyhalogen compound, a hydrous alkali metal sulfide, and a compound having an aliphatic ring structure that can be ring-opened by hydrolysis. Polyarylene sulfide with high productivity on an industrial scale by suppressing the distillation of aromatic polyhalogen compounds to the outside of the reaction vessel and reducing the time of the dehydration process A method for producing a resin can be provided.

  In order to increase the productivity when the polyarylene sulfide resin is produced, when dehydration is performed by increasing the temperature rise rate for heating the mixture in the reaction vessel, the water and the aromatic polyhalogen compound (A) are both The boiling composition collapses, and the aromatic polyhalogen compound (A) excessively distills out of the reaction vessel, resulting in a shift in the molar ratio between the aromatic polyhalogen compound (A) and the alkali metal sulfide in the polymerization step. A polyarylene sulfide resin having a molecular weight of 5 cannot be obtained. The operation of correcting the deviation of the molar ratio by returning or adding the aromatic polyhalogen compound (A) distilled out of the reaction vessel to the reaction vessel is very complicated and productive. It will be lowered. Therefore, by setting the temperature of the gas phase inside the reaction vessel in the range of 90 ° C. to 160 ° C. in step 1 of the present invention, water in the vaporized reaction mixture is distilled out of the reaction vessel, The vaporized aromatic polyhalogen compound (A) is refluxed to the liquid phase part to suppress distillation out of the reaction vessel. As a result, since the shift of the molar ratio between the aromatic polyhalogen compound (A) used in Step 1 and the hydrated alkali metal sulfide (B) is suppressed, the blending of the aromatic polyhalogen compound (A) in Step 1 The accuracy of quantity is greatly improved, and productivity on an industrial scale is dramatically improved.

  The temperature of the gas phase inside the reaction vessel is such that the aromatic polyhalogen compound (A) is efficiently refluxed to the liquid phase while efficiently distilling water out of the reaction vessel, and distilled out of the reaction vessel. Is particularly preferably in the range of 100 ° C. to 140 ° C. in the above range.

  Specific methods for distilling off the water in Step 1 include dehydration treatment with an aromatic polyhalogen compound (A), a hydrous alkali metal sulfide (B), and a compound having an aliphatic cyclic structure that can be opened by hydrolysis. A predetermined amount of (C) is charged into a reaction vessel, and in an open system, the vapor is cooled so that the temperature of the gas phase inside the reaction vessel is in the temperature range, and is at or above the boiling point of the hydrated alkali metal sulfide (B) In addition, the aromatic polyhalogen compound (A) is obtained by heating the liquid phase so that the water is removed by azeotropic distillation, specifically in the range of 90 to 220 ° C, preferably in the range of 100 to 200 ° C. In a liquid phase and water is distilled off to the outside of the reaction vessel.

Examples of the apparatus used in the step 1 include a dehydrator having a reaction vessel equipped with a stirring device, a vapor distillation line, a condenser, a decanter, a distillate return line, an exhaust line, a hydrogen sulfide capturing device, and a heating device. It is done. The reaction vessel used in the dehydration treatment in step 1 and the reaction or polymerization in step 2 is not particularly limited, but it is preferable to use a reaction vessel whose wetted part is made of titanium, chromium, zirconium or the like. Here, the open system of the present invention means that the reaction vessel is substantially open. For example, in the case of a general apparatus, a condenser is connected from a reaction vessel through a vapor distillation line, and the vapor heated and vaporized in the reaction vessel is condensed by the condenser, and the obtained liquid is separated by a decanter. The required effluent is returned to the reaction vessel through the distillate return line. Therefore, it is preferable that the part after the capacitor is opened to the atmosphere. Therefore, it is preferable that the decanter or the exhaust line is opened to the atmosphere. Specifically, the pressure in the gas phase inside the reaction vessel is preferably in the range of 0 MPa to 0.02 MPa as gauge pressure, and more preferably in the range of 0 MPa to 0.01 MPa.

  As a method for cooling the gas phase portion of the reaction vessel in the production method of the present invention, various known cooling methods such as a method for cooling the outside of the reaction vessel or a method for cooling inside the reaction vessel can be mentioned. For example, a method of flowing a refrigerant through an internal coil installed at the top of the reaction vessel, a method of flowing a refrigerant through an external coil or jacket wound around the top of the reaction vessel, and a reflux condenser installed at the top of the reaction vessel are used. Examples thereof include a method, a method in which water is applied to the upper portion outside the reaction vessel, and a method in which a gas such as air or nitrogen is blown onto the upper portion outside the reaction vessel. Any of the various cooling methods described above may be used as long as the gas phase portion in the reaction vessel is cooled and the amount of reflux of the aromatic polyhalogen compound (A) is increased. Among these, the method of applying water to the upper part outside the reaction vessel is preferable because it is easy to handle and the facility can be easily modified.

The timing for starting the cooling of the gas phase inside the reaction vessel is the aromatic polyhalogen compound (A), the hydrous alkali metal sulfide (B), the compound having an aliphatic cyclic structure that can be opened by hydrolysis ( C) charge a predetermined amount of the reaction vessel,
(A) At the same time as the heating of the liquid phase part is started,
(B) After the time when water and the aromatic polyhalogen compound (A) start to flow out by azeotropy,
(C) After the time when the temperature of the liquid phase exceeds 100 ° C,
(D) or the time after the temperature of the liquid phase portion reaches the boiling point of the aromatic polyhalogen compound (A). Among these, from the viewpoint of the balance that water is easily distilled out of the reaction vessel, the aromatic polyhalogen compound (A) is difficult to distill out of the reaction vessel, and the manufacturing cost can be easily reduced, It is preferable to start cooling the gas phase portion inside the reaction vessel after the time when the temperature of the phase portion exceeds 100 ° C.

  The compound (C) having an aliphatic cyclic structure that can be opened by hydrolysis used in the present invention is N-methyl-2-pyrrolidone, N-cyclohexyl-2-pyrrolidone, 2-pyrrolidone, 1,3-dimethyl-2. Examples include cyclic amides or cyclic ureas such as imidazolidinone, ε-caprolactam, N-methyl-ε-caprolactam, and sulfolanes such as sulfolane and dimethylsulfolane. Among these, N-methyl-2-pyrrolidone is particularly preferable in the present invention.

  Further, in the step 1, the aromatic polyhalogen compound (A), the hydrated alkali metal sulfide (B), and 1 mol of the hydrated alkali metal sulfide (B) can be opened by hydrolysis of less than 1 mol. The mixed liquid of the compound (C) having an aliphatic cyclic structure is dehydrated to obtain a solid alkali metal sulfide (b1), an alkali metal hydrosulfide (b2), and an alkali of the hydrolyzate of the compound (C). It is a process for producing a slurry containing a metal salt (c1). When the amount is 1 mol or more, a solid alkali metal sulfide (b1) is not generated, and side reactions are not suppressed, so that a high molecular weight polyarylene sulfide resin is efficiently used. Cannot be obtained.

  In the step 1, by adjusting the amount of the compound (C) having an aliphatic cyclic structure that can be ring-opened by hydrolysis with respect to the hydrous alkali metal sulfide (B), the solid content of the sulfidizing agent And the amount of the hydrolyzate of the compound (C) can be adjusted. That is, in step 1, for example, as shown in the following formula (1), a compound having an aliphatic cyclic structure that removes water contained in the hydrous alkali metal sulfide (B) by dehydration and can be opened by hydrolysis. (C) is a step of hydrolyzing and simultaneously forming a solid alkali metal sulfide (b1).

  As shown in the following formula (1), in the present invention, the hydrated alkali metal sulfide (B) is dehydrated to obtain a solid alkali metal sulfide (b1) and an alkali metal hydrosulfide (b2). However, the hydrated alkali metal sulfide (B) can be prepared and used by previously reacting the hydrated alkali metal hydrosulfide and the hydrated alkali metal hydroxide in a reaction vessel.

ここで、式（１）中、ｘ及びｙは（ｘ＋ｙ）が０．１〜３０を満足する数、ｚはＭＳＨ・ｘＨ_２Ｏに対して当量未満、好ましくは０．０１〜０．９であり、Ｍはアルカリ金属原子、Ｘは前記化合物（Ｃ）、Ｘ’はその加水分解物を表す。

Here, in the formula (1), x and y are numbers in which (x + y) satisfies 0.1 to 30, and z is less than an equivalent to MSH · xH ₂ O, preferably 0.01 to 0.9. Yes, M represents an alkali metal atom, X represents the compound (C), and X ′ represents a hydrolyzate thereof.

  Therefore, fat that can be ring-opened by hydrolysis with respect to 1 mol of the hydrated alkali metal sulfide (B) obtained by previously reacting the hydrated alkali metal hydrosulfide and the hydrated alkali metal hydroxide in the reaction vessel. When the compound (C) having a group cyclic structure is used in an amount of less than 1 mol, the sulfidizing agent is precipitated as a solid, and the intended slurry is obtained.

  On the other hand, the water used for hydrolysis of the compound (C) having an aliphatic ring structure that can be opened by hydrolysis is converted into aromatic polyhalogen compound (A) and alkali metal hydrosulfide (b2) in step 2. However, after the reaction, when the hydrolyzate of the compound (C) is closed to return to the compound (C), it is released into the reaction mixture and dissolves the alkali metal sulfide (b1), which is a solid content in the slurry. And converted into a hydrolyzate of the alkali metal hydrosulfide (b2) and the compound (C).

  Therefore, the amount of the alkali metal sulfide (b1), which is a solid content in the slurry, and the alkali metal hydrosulfide (b2) are adjusted by adjusting the amount of the compound (C) having an aliphatic cyclic structure in Step 1. ) Can be adjusted. In the present invention, the alkali metal sulfide (b1) is present in the form of a slurry with a solid content, and then the compound (C) having the aliphatic cyclic structure is hydrolyzed by performing a heterogeneous reaction in the slurry state in Step 2. The amount of the alkali metal salt of the product can be reduced, side reactions during polymerization of the polyarylene sulfide resin can be suppressed, and the molecular weight can be increased. Therefore, the charged amount of the compound (C) having an aliphatic cyclic structure in Step 1 is the compound (C) having an aliphatic cyclic structure that can be ring-opened by hydrolysis with respect to 1 mol of the hydrous alkali metal sulfide (B). ) Is less than 1 mol, and when it is 1 mol or more, the solid alkali metal sulfide (b1) is not generated, and side reactions are not suppressed, so that a high molecular weight polyarylene sulfide resin cannot be efficiently obtained. Among them, it is preferable to use the compound (C) having an aliphatic cyclic structure that can be ring-opened by hydrolysis with respect to 1 mol of the hydrous alkali metal hydrosulfide (B) at a ratio of 0.01 to 0.9 mol. In particular, 0.04 to 0.4 mol of the compound (C) having an aliphatic cyclic structure that can be ring-opened by hydrolysis with respect to 1 mol of the hydrous alkali metal sulfide from the point that such an effect becomes remarkable. It is preferable to use in proportion.

  Examples of the hydrated alkali metal sulfide (B) used in Step 1 include liquid or solid hydrates of compounds such as lithium sulfide, sodium sulfide, potassium sulfide, rubidium sulfide, cesium sulfide, and the like. It is preferable that it is -80 mass%, especially 35-65 mass%. Among these, a sodium sulfide hydrate is preferable from the viewpoint of reactivity.

  Further, in Step 1, in addition to the hydrated alkali metal sulfide (B), addition of an alkali metal hydroxide to perform dehydration treatment further promotes the production of solid alkali metal sulfide (b1).

  On the other hand, examples of the alkali metal hydroxide include lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide, and aqueous solutions thereof. In addition, when using this aqueous solution, it is preferable that it is an aqueous solution with a density | concentration of 20 mass% or more from the point that the spin-drying | dehydration process of the process 1 is easy. Among these, lithium hydroxide, sodium hydroxide, and potassium hydroxide are particularly preferable, and sodium hydroxide is particularly preferable. The amount of alkali metal hydroxide used is preferably in the range of 0.8 to 1.2 moles per mole of alkali metal hydrosulfide (b2) from the point of promoting the formation of solid alkali metal sulfide. In particular, the range of 0.9 to 1.1 mol is more preferable.

  In addition, the reaction mixture in the reaction vessel in the initial stage of dehydration has two layers of the aromatic polyhalogen compound (A) and the molten hydrous alkali metal sulfide. It precipitates in the form of fine particles and is uniformly dispersed in the aromatic polyhalogen compound (A). Further, dehydration is continued until almost all of the compound (C) having an aliphatic cyclic structure that can be opened by hydrolysis in the reaction mixture is hydrolyzed.

  As described above, in step 1 of the present invention, water is discharged out of the reaction vessel by dehydration, and the compound (C) having an aliphatic ring structure that can be ring-opened by hydrolysis is hydrolyzed. In which the solid alkali metal sulfide (b1) is precipitated. Therefore, when excess water is present in the reaction mixture in the reaction mixture, the compound (C) having an aliphatic ring structure that can be opened by hydrolysis in Step 2 is additionally added in the reaction mixture. Since a large amount of the alkali metal salt of the hydrolyzate of compound (C) is generated, a side reaction is induced and the high molecular weight of the target polyarylene sulfide resin is easily inhibited. Therefore, it is preferable that the amount of water in the reaction mixture after the dehydration treatment in Step 1 is as small as possible. Specifically, the content of solid alkali metal sulfide (b1) in the finally obtained slurry is determined as follows. The range of 0.1 to 0.99 mol per mol of the hydrous alkali metal sulfide (B) used in No. 1, more preferably the range of 0.4 to 0.98 mol, more preferably 0.6 to 0 The point is that it is within the range of 96 moles, and in particular, the operability in the next step 2 which is substantially free of moisture and the effect of increasing the molecular weight of the resulting polyarylene sulfide resin are significant. To preferred.

  The aromatic polyhalogen compound (A) used in step 1 can be used in the reaction of step 2 as it is. In step 2, the aromatic polyhalogen compound (A) may be added to the reaction mixture obtained in step 1.

  Examples of the aromatic polyhalogen compound (A) include p-dihalogenated benzene, m-dihalogenated benzene, o-dihalogenated benzene, 1,2,3-trihalogenated benzene, 1,2,4-trihalogen. Benzene, 1,3,5-trihalogenated benzene, 1,2,3,5-tetrahalogenated benzene, 1,2,4,5-tetrahalogenated benzene, 1,2,3,4,5- Pentahalogenated benzene, hexahalogenated benzene, 1,4,6-trihalogenated naphthalene, 2,5-dihalogenated toluene, 1,4-dihalogenated naphthalene, 1-methoxy-2,5-dihalogenated benzene, 4 , 4′-dihalogenated biphenyl, 3,5-dihalogenated benzoic acid, 2,4-dihalogenated benzoic acid, 2,5-dihalogenated nitrobenzene, 2, -Dihagenated ronitrobenzene, 2,4-dihalogenated anisole, p, p'-dihalogenated diphenyl ether, 4,4'-dihalogenated benzophenone, 4,4'-dihalogenated diphenyl sulfone, 4,4'-dihalogenated diphenyl Examples include sulfoxide, 4,4′-dihalogenated diphenyl sulfide, and compounds having an alkyl group having 1 to 18 carbon atoms as a nuclear substituent on the aromatic ring of each compound. Moreover, it is desirable that the halogen atom contained in each compound is a chlorine atom or a bromine atom.

  Among these, the bifunctional aromatic dihalogen compound is preferable from the viewpoint that the present invention can efficiently produce a linear high molecular weight polyarylene sulfide resin, and the final polyarylene sulfide resin obtained is particularly preferable. From the viewpoint of good mechanical strength and moldability, p-dichlorobenzene, m-dichlorobenzene, 4,4′-dichlorobenzophenone and 4,4′-dichlorodiphenyl sulfone are preferable, and p-dichlorobenzene is particularly preferable. When it is desired to give a branched structure to a part of the polymer structure of the linear polyarylene sulfide resin, 1,2,3-trihalobenzene, 1,2,4-trihalogenated together with the aromatic dihalogen compound. It is preferable to use a part of benzene or 1,3,5-trihalogenated benzene.

  The amount of the aromatic polyhalogen compound (A) used is not particularly limited, but it is an alkali metal from the viewpoint that the fluidity of the slurry obtained in step 1 is good and the reactivity and polymerizability in step 2 are excellent. The range of 0.2 to 5.0 mol per mol of sulfide is preferable, and the range of 0.3 to 2.0 mol is particularly preferable. The aromatic polyhalogen compound (A) can be used as it is in the subsequent process for producing the polyarylene sulfide resin, and may be additionally used if necessary in the subsequent process for producing the polyarylene sulfide resin. In such a case, it may be used after being reduced.

  In addition, a copolymer containing two or more different reaction units can be obtained by appropriately selecting and combining the aromatic polyhalogen compound (A). For example, p-dichlorobenzene and 4,4′-dichlorobenzophenone or Use in combination with 4,4′-dichlorodiphenylsulfone is particularly preferred because a polyarylene sulfide having excellent heat resistance can be obtained.

  Further, the alkali metal hydrosulfide (b2) can be subjected to the reaction in Step 2 by using the alkali metal hydrosulfide (b2) that is present in the slurry through Step 1.

  After the alkali metal hydrosulfide (b2) is consumed by the reaction with the aromatic polyhalogen compound (A), the hydrolyzate of the compound (C) involved in the reaction is represented by the following formula (2). Thus, the ring is closed to release water, which then dissolves the solid alkali metal sulfide in the slurry to produce again the alkali metal hydrosulfide (b2). Therefore, in the reaction in Step 2, the solid alkali metal sulfide (b1) is gradually converted into the necessary amount of alkali metal hydrosulfide (b2) and the alkali metal salt of the hydrolyzate of the compound (C) by such a cycle ( Since it is converted into c1), side reactions are suppressed.

  In the present invention, since the reaction or polymerization in step 2 proceeds by such a cycle of hydrolysis of the compound (C) and subsequent release of water by ring closure, water is added to the reaction mixture again in step 2. Although it is not necessary, in the present invention, the total amount of water content in the reaction mixture is the hydrous alkali metal sulfide (B) used in Step 1 in order to promote the dissolution of the solid alkali metal sulfide in the slurry. Less than an equivalent amount, preferably 0.02 to 0.9 mol, more preferably 0.04 to 0.4 mol, with respect to 1 mol of the hydrated alkali metal sulfide (B). It is preferable to add.

  In addition, as described above, the alkali metal hydrosulfide (b2) that is a raw material for the reaction or polymerization reaction in the step 2 is gradually changed from the alkali metal sulfide (b1) that is a solid content in the slurry to the alkali metal hydrosulfide. Although it is sequentially supplied to the reaction mixture by being converted to (b2), an alkali metal hydrosulfide (b2) may be separately added at an arbitrary stage of step 2 if necessary. Examples of the alkali metal hydrosulfide (b2) that can be used here include lithium hydrosulfide, sodium hydrosulfide, potassium hydrosulfide, rubidium hydrosulfide, cesium hydrosulfide, and hydrates thereof. Among these, lithium hydrosulfide and sodium hydrosulfide are preferable, and sodium hydrosulfide is particularly preferable.

  Further, a small amount of alkali metal hydroxide may be added in order to react with alkali metal hydrosulfide (b2) present in a trace amount in the alkali metal sulfide constituting the solid content of the slurry, or alkali metal thiosulfate.

  A specific method for performing the reaction and polymerization in Step 2 is to add water, an aromatic polyhalogen compound (A), an alkali metal hydrosulfide (b2), and an organic solvent to the slurry obtained through Step 1 as necessary. The reaction or polymerization is preferably performed in the range of 180 to 300 ° C, preferably in the range of 200 to 280 ° C. The polymerization reaction can be carried out at a constant temperature, but can also be carried out while raising the temperature stepwise or continuously.

  In addition, the amount of the aromatic polyhalogen compound (A) in Step 2 is specifically preferably in the range of 0.8 to 1.2 moles per mole of sulfur atoms in the reaction mixture, particularly 0.9 to The range of 1.1 mol is preferred from the viewpoint of obtaining a higher molecular weight polyarylene sulfide resin.

  In the reaction or polymerization reaction in Step 2, the compound (C) may be further added as an organic solvent. The total amount of the compound (C) used in the reaction is not particularly limited, but the compound (C) is 0.6 to 10 mol per mol of sulfur atom present in the reaction mixture. ) Is preferably added, and more preferably in the range of 2.0 to 6.0 mol in terms of enabling higher molecular weight of the polyarylene sulfide resin. In addition, from the viewpoint of increasing the concentration of the reactant per polymerization vessel volume, a range of 1.0 to 3.0 mol per mol of sulfur atoms present in the reaction mixture is preferable.

In the initial stage of the reaction or polymerization in step 2, the amount of water in the reaction mixture is substantially anhydrous. That is, the water used for the hydrolysis of the compound (C) in the dehydration step in the step 1 and the water added to the hydrolysis of the compound (C) as necessary after that are used as described above. Again, the hydrolyzate is released by a ring-closing reaction. At the same time, since it is used again for the production of the alkali metal hydrosulfide (b2) and the hydrolysis of the compound (C), water apparently does not exist in the reaction mixture, Since the hydrolysis of the compound (C) does not proceed when the solid content disappears, water is apparently observed in the reaction.
Therefore, in the step 2 of the present invention, it is preferable that the polymerization slurry is substantially anhydrous when the consumption rate of the solid alkali metal sulfide is 10%.

  For each step of the dehydration treatment in Step 1 and the reaction or polymerization in Step 2, each usual polymerization method such as a batch method, a batch method or a continuous method can be adopted. In both the dehydration step and the polymerization step, it is preferably performed in an inert gas atmosphere. Examples of the inert gas to be used include nitrogen, helium, neon, argon, etc. Among them, nitrogen is preferable from the viewpoint of economy and ease of handling.

  The post-treatment method of the reaction mixture containing the polyarylene sulfide resin obtained by the polymerization step is not particularly limited. For example, (1) after the completion of the polymerization reaction, the reaction mixture is left as it is, or an acid or a base is used. Then, the solvent is distilled off under reduced pressure or normal pressure, and then the solid after the solvent is distilled off is washed once or twice with a solvent such as water, acetone, methyl ethyl ketone, alcohols, and further neutralized. , Washing with water, filtration and drying, or (2) after completion of the polymerization reaction, the reaction mixture is mixed with water, acetone, methyl ethyl ketone, alcohols, ethers, halogenated hydrocarbons, aromatic hydrocarbons, aliphatic hydrocarbons, etc. Solvent (solvent that is soluble in the polymerization solvent used and is a poor solvent for at least polyarylene sulfide resin) is used as a precipitant. Or by precipitating a solid product such as polyarylene sulfide resin or inorganic salt and filtering, washing and drying, or (3) after completion of the polymerization reaction, the reaction mixture is mixed with a reaction solvent (or low An organic solvent having an equivalent solubility in the molecular polymer) and stirring, followed by filtration to remove the low molecular weight polymer, and then one or more times with a solvent such as water, acetone, methyl ethyl ketone, alcohols, etc. Examples of the method include washing, then neutralization, washing with water, filtration, and drying.

  In the post-treatment methods exemplified in the above (1) to (3), the polyarylene sulfide resin may be dried in a vacuum or in an inert gas atmosphere such as air or nitrogen. May be.

  The polyarylene sulfide resin thus obtained can be used as it is for various molding materials and the like, but may be oxidized and crosslinked by heat treatment in air or oxygen-enriched air or under reduced pressure conditions. The temperature of this heat treatment is preferably in the range of 180 ° C. to 270 ° C., although it varies depending on the target crosslinking treatment time and the atmosphere to be treated. In addition, the heat treatment may be performed in a state where the polyarylene sulfide resin is melted at a temperature equal to or higher than the melting point of the polyarylene sulfide resin using an extruder or the like. It is preferable to carry out at +100 degrees C or less.

  The polyarylene sulfide resin obtained by the production method of the present invention described in detail above is subjected to various heat processing methods such as injection molding, extrusion molding, compression molding, blow molding, etc., in heat resistance, molding processability, dimensional stability, etc. It can be processed into an excellent molded product.

  Further, the polyarylene sulfide resin obtained by the present invention can be used as a polyarylene sulfide resin composition combined with various fillers in order to further improve performance such as strength, heat resistance, and dimensional stability. I can do it. Although it does not restrict | limit especially as a filler, For example, a fibrous filler, an inorganic filler, etc. are mentioned. Examples of the fibrous filler include glass fiber, carbon fiber, silane glass fiber, ceramic fiber, aramid fiber, metal fiber, potassium titanate, silicon carbide, calcium sulfate, calcium silicate, and other natural fibers such as wollastonite. Can be used. Inorganic fillers include barium sulfate, calcium sulfate, clay, viroferrite, bentonite, sericite, zeolite, mica, mica, talc, talpulgite, ferrite, calcium silicate, calcium carbonate, magnesium carbonate, glass beads, etc. Can be used. Further, various additives such as a mold release agent, a colorant, a heat stabilizer, a UV stabilizer, a foaming agent, a rust inhibitor, a flame retardant, and a lubricant can be added as additives during the molding process.

  Furthermore, the polyarylene sulfide resin obtained according to the present invention can be appropriately selected from polyester, polyamide, polyimide, polyetherimide, polycarbonate, polyphenylene ether, polysulfone, polyethersulfone, polyetheretherketone, polyether depending on the application. Synthetic resins such as ketone, polyarylene, polyethylene, polypropylene, polytetrafluoroethylene, polydifluoroethylene, polystyrene, ABS resin, epoxy resin, silicone resin, phenol resin, urethane resin, liquid crystal polymer, or polyolefin rubber Alternatively, it may be used as a polyarylene sulfide resin composition containing an elastomer such as fluorine rubber or silicone rubber.

  Since the polyarylene sulfide resin obtained by the production method of the present invention also has various performances such as heat resistance and dimensional stability inherent in the polyarylene sulfide resin, for example, a connector, a printed circuit board, a sealing molded product, etc. Injection molding of automobile parts such as electrical / electronic parts, lamp reflectors and various electrical parts, interior materials such as various buildings, aircraft and automobiles, or precision parts such as OA equipment parts, camera parts and watch parts, or It is widely useful as a material for various molding processes such as compression molding, extrusion molding of composites, sheets, pipes, etc., or pultrusion molding, or as a material for fibers or films.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

(Measuring method of melt viscosity)
The melt viscosity (η) of the obtained polymer is an orifice having a former / latter ratio of 10/1 between a temperature of 300 ° C., a stress of 1.96 MPa, an orifice length and an orifice diameter using a flow tester manufactured by Shimadzu Corporation. Is a value measured after holding for 6 minutes.

Example 1
(Dehydration process: anhydrous sodium sulfide production process)
In a 1-liter autoclave of zirconium lining with stirring blades connected with a pressure gauge, thermometer, condenser, and decanter, 220.5 g (1.5 mol) of p-dichlorobenzene (hereinafter abbreviated as p-DCB), N-methyl 2-pyrrolidone 29.7 g (0.3 mol), 47.43 wt% aqueous NaOH solution 177.29 g (1.5 mol), and 48.71 wt% aqueous NaOH solution 123.18 g (1.5 mol) were charged. The temperature was raised in a nitrogen atmosphere while stirring.
Distillation of a mixed solution of water and p-DCB started at a liquid phase temperature of 128 ° C., and the temperature was raised to an internal temperature of 173 ° C. over 2 hours. The gas phase temperature gradually increased from 93 ° C. at the start of dehydration, and when the gas phase temperature reached 107 ° C., water was sprayed outside the upper flange of the autoclave to start cooling the gas phase portion. The amount of water spray was controlled so that the gas phase temperature did not exceed 110 ° C. The gas phase temperature at the end of the dehydration was 109 ° C. After distilling 177.98 g of water, the container was sealed. At that time, p-dichlorobenzene distilled by azeotropic distillation was separated by a decanter and returned to the container as needed, and the accumulated amount of p-dichlorobenzene returned to the container was 225 g. The inside of the container after the completion of dehydration was in a state where fine particulate anhydrous sodium sulfide was dispersed in p-dichlorobenzene.

(Polymerization process: PPS production process)
After completion of the dehydration step, the internal temperature is cooled to 160 ° C., 416.3 g (4.2 mol) of N-methyl-2-pyrrolidone is charged, the temperature is raised to 220 ° C., stirred for 2 hours, and then to 250 ° C. The temperature was raised and stirred for 1 hour. The final pressure was 0.34 MPa. After cooling, the resulting slurry was poured into 3 liters of water, stirred at 80 ° C. for 1 hour, and then filtered. The cake was again stirred with 3 liters of warm water for 1 hour, washed and filtered. This operation was repeated 4 times, and after filtration, dried at 120 ° C. overnight using a hot air dryer to obtain 154 g of white powdery PPS. The melt viscosity of this polymer was 66 Pa · s.

Example 2
(Dehydration process: anhydrous sodium sulfide production process)
In the dehydration step, the same operation as in Example 1 was performed except that the amount of water spray was controlled so that the gas phase temperature did not exceed 125 ° C. and the temperature was raised to an internal temperature of 173 ° C. over 1.5 hours. The gas phase temperature at the end of the dehydration was 125 ° C. The amount of distilled water was 177.98 g, and the cumulative amount of p-dichlorobenzene returned to the container was 677 g.
(Polymerization process: PPS production process)
The same operation as in Example 1 was performed, and the obtained polymer had a melt viscosity of 64 Pa · s.

Comparative Example 1
(Dehydration process: anhydrous sodium sulfide production process)
In the dehydration step, the same operation as in Example 1 was performed except that the gas phase portion was not cooled and the temperature was raised to an internal temperature of 173 ° C. over 2 hours. The gas phase temperature at the end of the dehydration was 166 ° C. The amount of distilled water was 177.97 g of water, and the cumulative amount of p-dichlorobenzene returned to the container was 721 g.
(Polymerization process: PPS production process)
The same operation as in Example 1 was performed, and the obtained polymer had a melt viscosity of 65 Pa · s.

Comparative Example 2
(Dehydration process: anhydrous sodium sulfide production process)
In the dehydration step, the same operation as in Example 1 was performed except that the gas phase portion was not cooled and the temperature was raised to an internal temperature of 173 ° C. over 3.3 hours. The gas phase temperature at the end of the dehydration was 168 ° C. The amount of distilled water was 177.9 g, and the cumulative amount of p-dichlorobenzene returned to the container was 347 g.
(Polymerization process: PPS production process)
The same operation as in Example 1 was performed, and the obtained polymer had a melt viscosity of 64 Pa · s.

Claims (6)

Step 1 and Step 2 below
Step 1: An aromatic polyhalogen compound (A), a hydrous alkali metal sulfide (B), and an aliphatic cyclic ring that can be opened by hydrolysis of less than 1 mole with respect to 1 mole of the hydrous alkali metal sulfide (B). The vapor of the mixed liquid of the compound (C) having a structure is cooled so that the temperature of the gas phase inside the reaction vessel is in the range of 90 ° C. to 160 ° C. in an open system, and the aromatic polyhalogen compound (A) The solid alkali metal sulfide (b1), the alkali metal hydrosulfide (b2), and the alkali of the hydrolyzate of the compound (C) were obtained while refluxing the liquid phase into the liquid phase and distilling off the water to the outside of the reaction vessel. Producing a slurry containing a metal salt (c1),
Step 2: Next, in the presence of the slurry, the aromatic polyhalogen compound (A), the alkali metal hydrosulfide (b2), and the alkali metal salt (c1) of the hydrolyzate of the compound (C) are reacted. A step of polymerizing,
A process for producing a polyarylene sulfide resin, in which is an essential production process. In Step 1, the ratio of 0.01 to 0.9 mol of the compound (C) having an aliphatic ring structure that can be ring-opened by hydrolysis as described above per 1 mol of the hydrous alkali metal sulfide (B). The method for producing a polyarylene sulfide resin according to claim 1, which is used in the above. The method for producing an alkali metal sulfide according to claim 1 or 2, wherein the aromatic polyhalogen compound (A) is an aromatic dihalogen compound. The solid alkali metal sulfide (b1) content in the slurry obtained in the step 1 is 0.1 to 0.99 mol per mol of the hydrous alkali metal sulfide (B) used in the step 1. Item 4. The method for producing a polyarylene sulfide resin according to any one of Items 1 to 3. The polyarylene sulfide resin according to any one of claims 1 to 4, wherein the polymerization slurry is substantially anhydrous when the consumption rate of the solid alkali metal sulfide (b1) in step 2 is 10%. Manufacturing method. After the completion of Step 1, the compound (C) having an aliphatic cyclic structure that can be further ring-opened by hydrolysis has a total amount of the compound (C) of 0.6 to 10 mol per mol of sulfur atoms present in the reaction mixture. The method for producing a polyarylene sulfide resin according to any one of claims 1 to 5, which is added so that