JPH07173290A - Production of polyarylene sulfide polymer - Google Patents

Abstract

PURPOSE:To produce a polyarylene sulfide polymer excellent in physical properties, such as toughness, with excellent reproducibility, with high output of polymer per unit volume of reactor, i.e., high productivity and with high economic efficiency in commercial production. CONSTITUTION:A process for producing a polyarylene sulfide polymer by the polycondensation of a sulfiding agent and a dihaloaromatic compound in an organic polar solvent while the azeotropically distilled water is removed out of the system, wherein the molar ratio of the solvent to the sulfiding agent is (1.0:1) to (3.5:1), the molar ratio of water to the sulfiding agent in the reaction system at the end of reaction is (0.05:1) to (0.9:1), and the molar ratio of water to the solvent in the reaction system is preferably (0.02:1) to (0.3:1).

Description

Detailed Description of the Invention

[0001]

The present invention relates to a polyarylene sulfide represented by polyphenylene sulfide (hereinafter abbreviated as PPS) by the reaction of a dihaloaromatic compound such as dihalobenzenes with a sulfidizing agent such as an alkali metal sulfide (hereinafter referred to as PPS). (Hereinafter referred to as PAS)). More specifically, the present invention is a method for obtaining PAS having excellent stability and high productivity by controlling the amount of water and the amount of solvent in the system during the polymerization reaction to a specific ratio with a relatively simple device. It is about.

In recent years, more and more heat-resistant thermoplastic resins have been required for electric and electronic parts, automobile parts and the like. Therefore, they have high heat resistance and physical properties such as moldability and dimensional stability. PAS typified by excellent PPS is of great importance, and the issue is how to increase the production amount with stable physical properties. The present invention provides a method for producing PAS with high productivity and stable physical properties.

[0003]

2. Description of the Related Art As a method for producing PAS typified by PPS, an alkali metal sulfide disclosed in (1) US Pat. In particular, sodium sulfide having crystal water (hereinafter abbreviated as hydrous sodium sulfide) is heated in a polar solvent to remove water contained in the hydrous sodium sulfide,
There is a method in which dichlorobenzene is added thereto and the mixture is heated and polymerized. However, in this method, in order to remove the water content of hydrous sodium sulfide (including the reaction product of hydrous sodium hydrosulfide and sodium hydroxide) which is one of the raw materials, a method of physically distilling by heating in a polymerization solvent is used. Because it depends on Sufficient dehydration is difficult, that is, 1 to 1.5 mol of water remains in the system with respect to 1 mol of a sulfidizing agent such as sodium sulfide, and it is difficult to control the residual water content. At the time of distilling water, the sulfide content in the metal sulfide is entrained in the form of hydrogen sulfide and becomes a loss, which changes the abundance of the sulfur content in the reaction system. When a considerable amount of water remains, the metal sulfide erodes the reaction vessel, and the eluted heavy metal ions hinder the formation of high molecular weight polymer.

As described above, due to the water content in the system, it is not possible to increase the molecular weight, or if the amount of solvent used for the sulfiding agent is reduced, a decomposition reaction occurs, or a polymer cannot be obtained with good reproducibility. There was such a problem. Therefore, various methods have been proposed for the purpose of reducing the amount of water in the system.

For example, (2) JP-A-5-239210 discloses an aqueous mixture of a sulfur source such as an alkali metal sulfide and an organic polar solvent (provided that the molar ratio of the organic polar solvent to the sulfur source is 0.15). / 1 to about 0.9 / 1), and the dehydrated mixture is mixed with a polyhalo-substituted aromatic compound and polymerized. In this method, it is possible to control the water remaining in the system before the polymerization to 1 mol or less per mol of the sulfur source, and it may be possible to increase the production amount per reactor volume. However, in this method, since the aqueous mixture containing a considerably small amount of solvent relative to the sulfur source is dehydrated, the amount of sulfur present in the reaction system fluctuates due to corrosion problems of the reactor at that time or loss of hydrogen sulfide during dehydration. Then, there is a problem that the reproducibility of the reaction is not good. Further, as shown in the examples of the publication, the viscosity of the obtained polymer is not so high and it cannot be said to be sufficient.

(3) JP-A-60-104130 discloses a mixture of an aromatic dihalide (which may contain a small amount of aromatic tri- or tetrahalide) and an organic solvent at 150 ° C. or higher. Discloses a method for producing a high molecular weight PAS, which comprises introducing a water-containing alkali metal sulfide at a rate at which water can be removed from a reaction mixture, and carrying out a polymerization reaction while keeping the system substantially anhydrous. . In this method, the polymerization reaction is carried out in an anhydrous state, but since the amount of water in the system is made too small, the solubility of the alkali metal sulfide in the solvent becomes small, so the reaction rate becomes slow and the polymerization reaction In addition to the problems that it takes a long time, side reactions such as decomposition reactions occur at the same time, it is necessary to introduce the hydrated alkali metal sulfide at a relatively high temperature, and there is a problem of corrosion of the reaction device.

Further, (4) JP-A-59-105027 discloses that raw materials such as an organic polar solvent, a sulfur source, and a dihalogeno aromatic compound are collectively charged and dehydrated while the temperature of the reaction system is raised, and further dehydrated. The polymerization reaction is carried out while continuing. The publication suggests that the molar ratio of the solvent to the sulfur source (sulfur source / solvent) is 1/2 to 1/15, which is a very wide range, but the water content in the system is anhydrous. However, it takes a long time to bring the system into an anhydrous state in which water cannot be detected, and there is also a problem that the reaction rate becomes remarkably slow.

(5) JP-A-3-35023 discloses a method for producing PAS in which a sulfur source and a dihalogenoaromatic compound are polymerized while dehydrating under pressure in an organic polar solvent. The publication does not specifically describe the molar ratio of the solvent to the sulfur source (sulfur source / solvent), but according to the examples, it is 1 / 5.7, which is clearly in the conventional range of solvent amount. On the other hand, the water content in the system is not specifically described, but it will be about 0.3 in consideration of the examples. Certainly, this method reduces the amount of water in the system compared to the conventional method. However, it is difficult to obtain a polymer having excellent physical properties with good reproducibility simply by reducing the amount of water in the system.

(6) JP-A-4-275334 discloses that an aqueous mixture of a sulfur source such as an alkali metal sulfide and an organic polar solvent (provided that the sulfur source is 0.36 mol per mol of the organic polar solvent). It is disclosed that the above) is dehydrated, the dehydrated mixture is mixed with a polyhalo-substituted aromatic compound, the mixture is polymerized, and degassing is performed during the polymerization to remove by-produced water. In this method, since a large amount of water is present in the initial stage of the reaction, the reaction in the initial stage of the polymerization is slow, and as a result, the reaction takes a long time, which is disadvantageous in that the productivity is improved.

[0010]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned drawbacks of the conventional production method and produces a polymer having high reproducibility and excellent physical properties such as toughness and stability, with high productivity and economically. The purpose is to provide a method of doing.

[0011]

Means for Solving the Problems As a result of intensive studies conducted by the present inventors in order to achieve the above object, in order to produce PAS with high productivity, the reaction time should be shortened or the volume of the reaction container per volume should be reduced. Although it is sufficient to increase the production amount, we focused on the point that it is important to strictly control both the amount of solvent and the amount of water in the polymerization system for that purpose. Moreover, as a method for this purpose, the present inventors have prepared a polyarylene sulfide polymer by polycondensing while removing azeotropically distilling water of a sulfidizing agent and a dihaloaromatic compound in an organic polar solvent to the outside of the system. The method is desirable, and in the method, the dihaloaromatic compound and the sulfide are mixed at a molar ratio of the organic polar solvent and the sulfiding agent (solvent / sulfiding agent) of 1.0 / 1 to 3.5 / 1. The reacting agent is reacted, and the molar ratio of water in the reaction system at the end of the reaction and the sulfiding agent (water / sulfiding agent) is 0.05 / 1 to 0.9.
It has been found that when the conditions such as / 1 are satisfied, the obtained polymer has excellent physical properties and is effective in achieving the improvement of productivity which is the object of the present invention.

That is, the present invention provides a method for producing a polyarylene sulfide polymer, which comprises polycondensing while removing azeotropically distillatively distilling water of a sulfidizing agent and a dihaloaromatic compound in an organic polar solvent, while carrying out polycondensation. The molar ratio of the organic polar solvent and the sulfiding agent (solvent / sulfiding agent) is 1.0 / 1 to 3.5 / 1, and water in the reaction system at the end of the reaction and the sulfiding agent The present invention provides a method for producing PAS in which the molar ratio (water / sulfiding agent) of 0.05 / 1 to 0.9 / 1 is an essential condition. Polymerization under such essential conditions makes it possible to obtain a polymer having excellent physical properties, particularly toughness after crosslinking, with extremely high productivity.

[0013]

[Structure] In the present invention, the terms "sulfiding agent", "dihaloaromatic compound" and "solvent" include the case where each of the compounds or substances referred to is a mixture within the defined range. Must be understood. For example, the present invention includes, as one specific example, the case where the “dihalo aromatic compound” is composed of a plurality of types of compounds and the PAS produced is a copolymer.

(Production of Polymer) The method for producing PAS according to the present invention is based on a dehalogenation / sulfurization reaction of a dihaloaromatic compound with a sulfidizing agent.

(Sulfiding Agent) Examples of the sulfiding agent used in the present invention include alkali metal sulfides, alkali metal hydrosulfides, and mixtures thereof.

Examples of the alkali metal sulfides include lithium sulfide, sodium sulfide, potassium sulfide, rubidium sulfide, and cesium sulfide. These may be used alone or in combination of two or more. You may use it. Further, the alkali metal sulfide is an anhydride,
Either a hydrate or an aqueous solution may be used, but it is preferable to use a hydrate or an aqueous solution because the purpose of the present invention is met.

Among the above alkali metal sulfides, sodium sulfide and potassium sulfide are preferable, and sodium sulfide is particularly preferable. These alkali metal sulfides can be obtained by reacting an alkali metal hydrosulfide with an alkali metal base or a hydrogen sulfide with an alkali metal base. However, even if prepared in the reaction system, those prepared outside the reaction system can be used. You can use it.

Examples of alkali metal hydrosulfides include lithium hydrosulfide, sodium hydrosulfide, potassium hydrosulfide, rubidium hydrosulfide, and cesium hydrosulfide. These may be used alone or in combination of two kinds. The above may be mixed and used. The above-mentioned alkali metal hydrosulfide may be used in any form of anhydrate, hydrate and aqueous solution, but it is preferable to use hydrate or aqueous solution because it meets the object of the present invention.

Among the above alkali metal hydrosulfides, sodium hydrosulfide and potassium hydrosulfide are preferable, and sodium hydrosulfide is particularly preferable. These alkali metal hydrosulfides can also be obtained by reacting hydrogen sulfide with an alkali metal base, but they may be prepared in the reaction system or may be prepared outside the reaction system.

Examples of alkali metal bases include alkali metal hydroxides. Examples of the alkali metal hydroxide include lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, and cesium hydroxide, which may be used alone or in combination with 2
You may mix and use 1 or more types.

Of the above alkali metal hydroxide compounds, lithium hydroxide, sodium hydroxide and potassium hydroxide are preferable, and sodium hydroxide is particularly preferable. In any of the above cases, a small excess of alkali metal base may be added to remove impurities that are present in trace amounts in the alkali metal sulfide and the alkali metal hydrosulfide.

(Dihaloaromatic Compound) The dihaloaromatic compound corresponding to the monomer forming the skeleton of the aromatic sulfide polymer has an aromatic nucleus and two halo substituents on the nucleus. And can be polymerized via a dehalogenation / sulfurization reaction with a sulfidizing agent such as an alkali metal sulfide. Therefore, the aromatic nucleus may have various substituents which do not inhibit the dehalogenation / sulfurization reaction, in addition to the case where the aromatic nucleus is composed of only aromatic hydrocarbon.

Specifically, examples of the dihaloaromatic compound used in the present invention include compounds represented by the following formulas (A) to (D).

[0024]

[Chemical 1]

Here, each substituent has the following meaning. X: Cl, Br, I or F. In particular, at least one halogen selected from the group consisting of Cl and Br. Y: -R, -OR, -COOR, -COONa, -CN
And -NO ₂ (R is selected from the group consisting of H, an alkyl group, a cycloalkyl group, an aryl group and an aralkyl group). Here, it is usual that the alkyl group or the alkyl group portion has about 1 to 18 carbon atoms, and the aryl group or the aryl group portion has about 6 to 18 carbon atoms.

[0026]

[Chemical 2]

(R 'and R''are selected from the group consisting of H, an alkyl group, a cycloalkyl group, an aryl group and an aralkyl group). Here, the alkyl group or alkyl group portion and the aryl group or aryl group portion are defined as above.

In the formula (A), m and n are respectively m =
2, an integer of 0 ≦ n ≦ 4. In the formula (B), a and b are respectively a = 2 and 0 ≦ b ≦ 6. In the formula (C), c, d,
e and f are 0 ≦ c ≦ 2, 0 ≦ d ≦ 2, and c + d, respectively.
= 2, an integer of 0 ≦ e, f ≦ 2. In the formula (D), g, h, i
And j are 0 ≦ g ≦ 2, 0 ≦ h ≦ 2, and g + h =, respectively.
An integer of 2, 0 ≦ i, j ≦ 2.

The following are examples of the dihalogen-substituted aromatic compound of the above general formula. p-dihalobenzene, m-dihalobenzene, o-dihalobenzene, 2,
5-dihalotoluene, 1,4-dihalonaphthalene, 1-
Methoxy-2,5-dihalobenzene, 4,4'-dihalobiphenyl, 3,5-dihalobenzoic acid, 2,4-dihalobenzoic acid, 2,5-dihalonitrobenzene, 2,4-dihalonitrobenzene, 2 , 4-dihaloanisole, p,
p'-dihalodiphenyl ether, 4,4'-dihalobenzophenone, 4,4'-dihalodiphenyl sulfone,
4,4'-dihalodiphenyl sulfoxide, 4,4'-
Dihalodiphenyl sulfide and the like, among which p-
Dihalobenzene, m-dihalobenzene, 4,4′-dihalobenzophenone and 4,4′-dihalodiphenyl sulfone are preferred, and among them, p-dichlorobenzene,
m-Dichlorobenzene, 4,4'-dichlorobenzophenone and 4,4'-dichlorodiphenyl sulfone are particularly preferably used.

As described above, it is possible to obtain a copolymer containing two or more different reaction units by appropriately selecting and combining dihaloaromatic compounds. When p-dichlorobenzene and 4,4′-dichlorobenzophenone or 4,4′-dichlorophenyl sulfone are used in combination,

[0031]

[Chemical 3]

Unit and

[0033]

[Chemical 4]

Unit or

[0035]

[Chemical 5]

A copolymer containing units can be obtained. However, copolymerization is possible, but when p-dihalobenzene is used in a dihaloaromatic compound in an amount of 70 mol% or more, preferably 90 mol% or more, more preferably 95 mol% or more, various physical properties are excellent. It is preferable because PPS can be obtained.

The amount of the dihaloaromatic compound used in the present invention is preferably 0.8 to 1.3 mol per mol of the sulfidizing agent, and particularly 0.9 to 1.10 mol is excellent in physical properties. To obtain the polymer.

Although the PAS according to the present invention is a polymer of the above dihaloaromatic compound, it is a monohalo compound (not necessarily an aromatic compound) for forming the terminal of the produced polymer or for controlling the polymerization reaction or the molecular weight. It is also possible to use a polyhalo compound of trihalo or higher (not necessarily an aromatic compound) in order to form a branched or crosslinked polymer. Specific examples where these monohalo or polyhalo compounds are aromatic compounds will be apparent to those skilled in the art as the monohalo or polyhalo derivatives of the above specific examples. Specifically, a branched phenylene sulfide polymer can be obtained, for example, by using dihalobenzene in combination with a slight amount of trichlorobenzene. The amount of the monohalo or polyhalo compound used varies depending on the purpose or the reaction conditions and cannot be specified unconditionally, but is preferably 0.
It is 1 mol or less, more preferably 0.05 mol or less.

(Solvent and Water) The organic polar solvent used in the polymerization reaction of the present invention is an organic polar solvent having no active hydrogen, that is, an aprotic type organic polar solvent.

This solvent must not unduly hinder the polymerization reaction of the present invention. Further, this solvent should have such a solubility that it can dissolve at least the dihaloaromatic compound as the raw material and the sulfiding agent that gives S ²⁻ to a concentration necessary for the reaction. Therefore, this solvent is usually a polar solvent having nitrogen, oxygen and / or sulfur atoms. Further, it is desirable that this solvent is not capable of participating in the same dehalogenation / sulfurization reaction as the starting dihaloaromatic compound. Thus, for example, it is desirable that it is not a haloaromatic hydrocarbon.

Since the solvent used in the present invention is to provide a controlled minute amount of water to the polymerization reaction,
It is desirable that this water be solvable as a solute.

As is clear from the production method of the present invention, the boiling point of the solvent used must be higher than that of water. Specific examples of such a solvent include (1)
Amides such as hexamethylphosphoric triamide (H
MPA), N-methylpyrrolidone (NMP), N-cyclohexylpyrrolidone (NCP), N-methylcaprolactam, tetramethylurea (TMU), dimethylformamide (DMF), dimethylacetamide (DMA),
In addition, (2) etherified polyacetylene glycol such as polyethylene glycol dialkyl ether (polymerization degree up to about 2000, alkyl group is about C _{1 to} C ₂₀ )
, And (3) sulfoxides such as tetramethylene sulfoxide, dimethyl sulfoxide (DMSO) and others. Among these, N-methylcaprolactam and NMP are particularly preferable because they have high chemical stability.

The amount of the solvent used varies depending on the type of solvent used and the amount of water relative to the solvent in the system, but it is an object of the present invention to maintain the viscosity of the reaction system which allows a uniform polymerization reaction. In order to increase the production amount of the polymer per volume of the reaction vessel and improve the productivity, the amount should be within the range of 1.0 to 3.5 mol per mol of the sulfidizing agent used for the polymerization. Further, a more preferable amount of solvent used is 1.2 to 3.0 mol per mol of the sulfidizing agent.

The water for adjusting the water content in the polymerization system or the water content of the sulfidizing agent may be any water that does not inhibit the reaction, so that the reaction such as distilled water or ion-exchanged water may be inhibited. Water free of anions and cations is preferable.

Generally, the amount of water to be present in the polymerization reaction of the present invention is preferably as low as possible in order to avoid concurrent occurrence of hydrolysis reaction and the like. However, when the sulfiding agent used is a hydrate or the like, even if the sulfiding agent is dehydrated by heating in an organic polar solvent, 1 mol or more remains in the system with respect to 1 mol of the sulfiding agent. It is difficult to reduce the water content in the system. Therefore, the dihaloaromatic compound is added to the reaction system to polymerize and the liberated water is dehydrated. Further, even if the dehydration operation as described above is performed, it is very difficult to completely dehydrate the inside of the reaction system, and there is a problem that the reaction rate becomes remarkably slow. In the polymerization reaction of the present invention, the amount of water to be present in the reaction system at the end of the reaction is 0.05 to 0.9 per mol of the sulfidizing agent.
The amount is preferably 0.05 to 0.5 mol, more preferably 0.05 to 0.3 mol. Particularly, in the method of the present invention, the water content in the system is not limited only to the amount of the sulfidizing agent, and it is more preferable to specify the water content in the system to the amount of the solvent. Is obtained.
The amount is 0.01 to 0.3 with respect to 1 mol of the organic polar solvent.
Is. (Polymerization) Polymerization according to the present invention is carried out by heating a mixture of an organic polar solvent, a sulfidizing agent and a dihaloaromatic compound,
Dehydration is carried out by azeotropic distillation or the like, and while continuing the dehydration operation, the temperature is raised to a temperature at which polymerization is possible to carry out the polymerization reaction, and the water content in the reaction system is a predetermined amount, that is, 1 mol of the sulfidizing agent used. On the other hand, when the amount becomes 0.05 to 0.9 mol, the reaction system is closed to carry out a further polymerization reaction, or a mixture of an organic polar solvent and a sulfidizing agent is heated if necessary, and dehydration operation is carried out by azeotropic distillation or the like. The amount of water in the reaction system is adjusted to 1 to 1.5 mol with respect to 1 mol of the sulfidizing agent, and then the dihaloaromatic compound is added all at once or continuously while continuing the dehydration operation. Polymerization is performed, and when the amount of water in the reaction system reaches a predetermined amount, that is, 0.05 to 0.9 mol with respect to 1 mol of the sulfidizing agent used, the reaction system is closed and a further polymerization reaction is performed.

The temperature at which polymerization is carried out while dehydrating is 18
It is 0 to 280 ° C., preferably 200 to 260 ° C., more preferably 210 to 250 ° C. If the temperature is lower than 180 ° C., the polymerization reaction hardly progresses, and if it is 280 ° C. or higher, the decomposition reaction of the polymer or solvent easily occurs. Further, the temperature at which the reaction system further polymerizes after reaching a predetermined water content is 2
The temperature is from 00 to 300 ° C., preferably from 210 to 280 ° C., more preferably from 220 to 260 ° C. When the temperature is lower than 200 ° C., the polymerization reaction is slow, and when the temperature is 300 ° C. or higher, the decomposition reaction of the polymer or solvent easily occurs.

The reaction time for polymerization while dehydration is 0.1 to 40 hours, preferably 0.5 to 20 hours, more preferably 1 to 10 hours. The reaction time depends on the type and amount of the starting materials used, or the reaction temperature, and therefore cannot be specified unconditionally. However, if the time is less than 0.1 hours, the dehydration operation is likely to be insufficient, and if 40 hours or more, the present invention is not performed. It goes against the goal of improving productivity.

The reaction time for further polymerization after the reaction system has reached a predetermined water content is 0 to 40 hours, preferably 0.5 to 20 hours, more preferably 1 to 10 hours. The reaction time depends on the type and amount of the raw materials used, or the reaction temperature, and therefore cannot be specified unconditionally, but if a polymer having sufficient physical properties such as molecular weight at the end of the dehydration operation can be obtained, further polymerization reaction is not necessary. Further, even if the polymerization reaction is required, it is against the objective of the present invention to improve the productivity for 40 hours or more.

In the polymerization reaction of the present invention, it is preferable to use a polymerization vessel whose wetted part is made of titanium, chromium or the like, and usually in an atmosphere of an inert gas such as nitrogen, helium or argon, which is particularly economical. Nitrogen is preferred from the viewpoints of properties and easy handling.

The reaction pressure is not particularly limited because it cannot be unconditionally specified because it depends on the type and amount of the starting materials and the solvent used, the reaction temperature and the like. Further, the adjustment of the reaction solution and the reaction for producing the copolymer may be a one-step reaction conducted at a constant temperature, a multi-step reaction in which the temperature is raised stepwise, or the temperature is continuously changed. It doesn't matter if it is a formal reaction.

To recover the polymer, at the end of the reaction, first, the reaction mixture as it is, or after adding an acid or a base, is heated under reduced pressure or atmospheric pressure to distill off only the solvent, and then the bottom solids are dried with water. It can be carried out by washing once or twice or more with a solvent such as acetone, acetone, methyl ethyl ketone, alcohols, and then neutralizing, washing with water, filtering and drying. Alternatively, after completion of the reaction, a solvent such as water, acetone, methyl ethyl ketone, alcohols, ethers, halogenated hydrocarbons, aromatic hydrocarbons and aliphatic hydrocarbons (soluble in the used polymerization reaction) is added to the reaction mixture. And a poor solvent for at least the produced polymer) is added as a precipitating agent to precipitate a solid product such as a polymer or an inorganic salt, which is filtered, washed and dried. It can also be done by doing. The "washing" in these cases can be carried out in the form of extraction. Also,
After completion of the reaction, a reaction solvent (or a solvent having the solubility of a low molecular weight polymer equivalent thereto) is added to the reaction mixture, and the mixture is stirred, filtered to remove the low molecular weight polymer, and then water, acetone, methyl ethyl ketone, alcohols. It can also be performed by washing once or twice or more with a solvent such as, and then neutralizing, washing with water, filtering and drying. Drying is performed by heating the isolated polymer to a temperature at which a solvent such as water is substantially evaporated. Drying may be performed under vacuum,
It may be performed in air or in an atmosphere of an inert gas such as nitrogen.

In any method, unless an organic acid salt is made to coexist as the third salt, the problem of contamination by the organic acid salt that is to be dissolved and released in the wash water does not occur. The obtained polymer can be used as it is for various molding materials, etc., but it can be thickened by heat treatment in air or oxygen-enriched air or under reduced pressure. After carrying out, it may be used for various molding materials and the like. The heat treatment temperature varies depending on the treatment time and the atmosphere to be treated, and therefore cannot be specified unconditionally, but it is usually preferable to perform the heat treatment at 180 ° C or higher. If the heat treatment temperature is less than 180 ° C., the rate of thickening is very slow and productivity is poor, which is not preferable. The heat treatment may be performed in a molten state at a temperature not lower than the melting point of the polymer using an extruder or the like. However, due to the possibility of polymer deterioration or workability, the melting point plus 100 ° C
It is preferable to perform the following.

The polymer obtained according to the present invention has a conventional P content.
Similar to AS, it is possible to obtain a molded product excellent in heat resistance, moldability, dimensional stability, etc. by various melt processing methods such as injection molding, extrusion molding, compression molding, blow molding as it is. However, in order to further improve performances such as strength, heat resistance and dimensional stability, it is also possible to use it in combination with various fillers within a range not impairing the object of the present invention.

Examples of the filler include fibrous filler and inorganic filler. As the fibrous filler, glass fiber, carbon fiber, silane glass fiber, ceramic fiber, aramid fiber, metal fiber, potassium titanate, silicon carbide,
Fibers such as calcium sulfate and calcium silicate and natural fibers such as wollastonite can be used. Further, as the inorganic filler, barium sulfate, calcium sulfate, clay, biferrite, bentonite, sericite, zeolite, mica, mica, talc, atalpulgite, ferrite, calcium silicate, calcium carbonate, magnesium carbonate, glass beads and the like. Can be used.

Further, a small amount of a release agent, a colorant, a heat stabilizer, an ultraviolet stabilizer, a foaming agent, a rust preventive, a flame retardant, an additive as an additive in the molding process within a range not departing from the object of the present invention. A lubricant and a coupling agent can be contained. Further, similarly, the following synthetic resins and elastomers can be mixed and used. These synthetic resins include polyester, polyamide, polyimide, polyetherimide,
Polycarbonate, polyphenylene ether, polysulfone, polyether sulfone, polyether ether ketone, polyether ketone, polyarylene, polyethylene, polypropylene, polytetrafluoride ethylene, polydifluoride ethylene, polystyrene, ABS resin, epoxy resin, silicone resin , Phenol resin, urethane resin, liquid crystal polymer, etc., and the elastomer includes polyolefin rubber, fluororubber, silicone rubber, etc.

The polymer and its composition of the present invention have excellent heat resistance and dimensional stability as in the case of PPS obtained by the conventional method. Therefore, for example, electrical / electronic materials such as connectors, printed circuit boards, and molded encapsulation products can be obtained. Injection molding / compression molding of parts, lamp reflectors / automotive parts such as various electrical component parts, interior materials for various buildings and aircraft / automobiles, precision parts such as office automation equipment parts / camera parts / watch parts, or Extrusion molding of composites, sheets, pipes, etc.
Molding materials or fibers with excellent heat resistance, moldability, dimensional stability, etc. in various molding fields such as pultrusion
Used as a film.

[0057]

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

Reference Example 1 Raw materials used 1. Sulfidating agent (alkali metal sulfide) Crystalline sodium sulfide (pentahydrate) (hereinafter Na ₂ S ・ 5H ₂
(Abbreviated as O) is a product of Sankyo Kasei Co., Ltd. Wako Pure Chemical Industries, Ltd. product is used for crystalline sodium sulfide (9-hydrate) (hereinafter abbreviated as Na ₂ S.9H ₂ O).

2. Solvent N-methylpyrrolidone (hereinafter, abbreviated as NMP) uses a product manufactured by Mitsubishi Kasei.

3. Dihalo aromatic compound p-dichlorobenzene (hereinafter abbreviated as p-DCB)
Is a product of Sumitomo Chemical Co., Ltd.

<Evaluation of Physical Properties> The melt viscosity (η) of the obtained polymer was measured by using a Koka type flow tester (3).
16 ° C, shear rate 100 / sec, nozzle hole diameter 0.5 mm,
Length 1.0 mm).

The toughness of the polymer was evaluated by a bending test. The method of the bending test will be described in detail below. The obtained polymer was melt-kneaded at 300 ° C. using a small extruder and pelletized, and then a small injection molding machine was used to obtain a thickness of 2.0 mm, Width 10.0 mm, length 60.0 m
A sample piece of m was prepared, and a bending test was performed using this sample piece. Bending test, span length 30.0mm,
The test speed was 1.5 mm / min.

Comparative Example 1 A stainless steel (titanium lining) 4 liter autoclave equipped with a stirring blade, in which a temperature sensor, a cooling tower, a dropping tank, a dropping pump, and a distillate separating tank were connected, was placed in a Na ₂ S.9H ₂ O 1200. Water-NM was prepared by charging 9 g (5.0 mol) and NMP 991 g (10.0 mol) and raising the temperature to 200 ° C. under a nitrogen atmosphere.
The P mixture was distilled off. The composition of the distillate is NMP138
g, 687 g of water, and 33 mmol of ionic sulfur.
Close the system, then raise the system to 220 ℃ and p-DC
A solution in which 735.0 g (5.0 mol) of B was dissolved in 400 g of NMP was added dropwise over 2 hours. 220 after completion of dropping
Hold at 3 ° C for 3 hours. Then, the temperature was raised to 250 ° C. over 1 hour, and the temperature was maintained for 1 hour to complete the reaction.
The slurry after the reaction had a strong offensive odor (decomposition odor), and no polymer was obtained.

Example 1 In a 4 liter autoclave, 1200.9 g (5.0 mol) of Na ₂ S.9H ₂ O and N were added.
1090 g (11.0 mol) of MP was charged and the water-NMP mixture was distilled off by raising the temperature to 200 ° C. under a nitrogen atmosphere. Furthermore, the internal temperature was raised to 220 ° C. while continuing the dehydration operation under pressure, and at that temperature, a solution in which 735.0 g (5.0 mol) of p-DCB was dissolved in 400 g of NMP while continuing the dehydration operation. Was added dropwise over 2 hours. After completion of the dropping, the mixture was held at 220 ° C. for 3 hours while dehydrating. P-DC azeotropically distilled with water during dehydration operation
B was continuously returned to the autoclave. The reaction system was closed and the dehydration operation was completed. After that, the temperature was raised to 250 ° C. over 1 hour and the temperature was maintained for 1 hour to complete the reaction. When the distillate was analyzed, NMP 265 g, water 778 g,
It was 52 mmol of ionic sulfur.

The obtained slurry was poured into 20 liters of water, stirred at 80 ° C. for 1 hour and then filtered. The cake was again stirred with 5 liters of hot water for 1 hour, washed, and then filtered. This operation was repeated 4 times, filtered, and then dried overnight (120 ° C.) in a hot air drier to obtain a white powdery polymer.
18 g was obtained. The melt viscosity of the obtained polymer was 380 poise.

Next, the obtained polymer was heat-treated at 230 ° C. in a hot-air circulating dryer to thicken it to 1520 poise. Next, a sample piece was prepared using this polymer, and a bending test was performed. The measurement results are shown in Table 1.

[0067] [Example 2] Each of the amounts of raw materials used, NMP 793g (8.0 mol), Na ₂ S · 9H ₂
To 1561.2 g (6.5 mol) of O, the amount of the raw material used for dropping was p-DCB955.5 g (6.5 mol), N
The same procedure as in Example 1 was carried out except that MP was changed to 520 g. However, the hold time at 220 ° C. after completion of the dropping was 5 hours. Water in the distillate is 1020 g, NMP is 382
g and ionic sulfur 76 mmol. The polymer obtained was 667 g, and the melt viscosity was 410 poise. In addition, a bending test was performed by performing a thickening operation as in Example 1. The results are shown in Table 1.

Example 3 p-DCB 735.0 g (5.0 mol) Na ₂ S.5H was placed in a 4-liter autoclave.
₂ O 840.6 g (5.0 mol), NMP 1487 g
(15.0 mol) was charged, the temperature was raised to 200 ° C. under a nitrogen atmosphere, the temperature was raised to 220 under pressure, and dehydration operation was further performed at that temperature for 5 hours. The p-DCB distilled azeotropically with water during the dehydration operation was continuously returned to the autoclave. The reaction system is closed and the dehydration operation is completed.
The temperature was raised to 0 ° C over 1 hour, and the temperature was maintained for 1 hour to complete the reaction. Analysis of the distillate showed that NMP2
It was 28 g, water 424 g, and ionic sulfur 62 mmol. The polymer obtained was 522 g, and the melt viscosity was 450 poise. Further, a thickening operation was performed in the same manner as in Example 1,
A bending test was performed. The results are shown in Table 1.

[Comparative Example 2] The amounts of the raw materials used were 1586 g (16.0 mol) of NMP and Na ₂ S.9, respectively.
720.5 g (3.0 mol) of H ₂ O was added with 441.0 g (3.0 mol) of p-DCB, the amount of the raw material used for dropping.
The same procedure as in Example 1 was performed except that 240 g of NMP was used.
The water content in the distillate was 470 g, NMP was 167 g, and ionic sulfur was 29 mmol. The polymer obtained is 30
7 g, melt viscosity was 210 poise. In addition, a bending test was performed by performing a thickening operation as in Example 1. The results are shown in Table 1.

[0070]

[Table 1] Melt viscosity ¹⁾ : Melt viscosity before thickening treatment, melt viscosity ²⁾ : Melt viscosity after thickening treatment

[0071]

INDUSTRIAL APPLICABILITY A method for producing a polyarylene sulfide polymer in which polycondensation is carried out while removing azeotropically distillatively distilling water of a sulfidizing agent and a dihaloaromatic compound in an organic polar solvent, According to the method of the present invention, in which the molar ratio between the sulfide and the sulfidizing agent and the molar ratio between water and the sulfiding agent in the reaction system at the end of the reaction are within specific ranges, PAS excellent in physical properties such as toughness and stability is obtained. Can be manufactured with high productivity and high reproducibility.

Claims (5)

[Claims] 1. A process for producing a polyarylene sulfide polymer, which comprises polycondensing while removing azeotropically distillatively distilling water of a sulfidizing agent and a dihaloaromatic compound in an organic polar solvent, wherein the organic polar The molar ratio of the solvent and the sulfidizing agent (solvent / sulfiding agent) is 1.0 / 1 to
3.5 / 1, and the molar ratio of water in the reaction system at the end of the reaction to the sulfidizing agent (water / sulfiding agent) is 0.0.
The method for producing a polyarylene sulfide polymer, which is 5/1 to 0.9 / 1. 2. A dihalo aromatic compound after dehydrating an aqueous mixture of a sulfidizing agent and an organic polar solvent to adjust the amount of water in the aqueous mixture to 1 to 1.5 moles per 1 mole of the sulfiding agent. A compound is added and polycondensation is carried out while removing azeotropically distilled water out of the system. At that time, the molar ratio of the organic polar solvent and the sulfidizing agent (solvent / sulfiding agent) is 1. 0/1 to 3.5 / 1, and the molar ratio of water in the reaction system at the end of the reaction to the sulfidizing agent (water / sulfiding agent) is 0.05 / 1 to 0.9 / 1. A method for producing a polyarylene sulfide polymer, which comprises: 3. The molar ratio of the organic polar solvent and the sulfidizing agent (solvent / sulfiding agent) is 1.2 / 1 to 3.0 / 1.
The manufacturing method according to claim 1, wherein 4. The production method according to claim 1, wherein the molar ratio of water in the reaction system to the organic polar solvent (water / solvent) is 0.02 / 1 to 0.3 / 1. 5. The production method according to claim 1, wherein the dihalo aromatic compound is a dihalobenzene, and the obtained polyarylene sulfide is polyphenylene sulfide.