JP2013072007A - Method of recovering cyclic polyarylene sulfide - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the captioned problem in scale-up, providing a method of recovering efficiently cyclic PAS (Polyarylene Sulfide) of high purity even in a production facility for the cyclic PAS.SOLUTION: The method of recovering an organic polar solvent (c) by solid-liquid separation, from the organic polar solvent (c) containing at least the cyclic polyarylene sulfide (a) and a linear polyarylene sulfide (b) is disclosed, wherein the solvent is transferred to a solid-liquid separator at a temperature range of a boiling point or less of the organic polar solvent (c) in the atmospheric pressure with a required stirring power applied to the mixture being 2.0 kWh/mor less.

Description

  The present invention relates to a process for recovering cyclic polyarylene sulfide. More particularly, the present invention relates to a more efficient method for recovering cyclic polyarylene sulfide.

  Aromatic cyclic compounds can be applied to highly functional materials and functional materials based on properties resulting from their cyclic properties, for example, properties as compounds with inclusion ability, and high molecular weight linear forms by ring-opening polymerization In recent years, it has attracted attention due to its specificity derived from its structure, such as its use as an effective monomer for polymer synthesis. Cyclic polyarylene sulfide (hereinafter, polyarylene sulfide may be abbreviated as PAS) also belongs to the category of aromatic cyclic compounds and is a notable compound as described above.

  A method for producing a mixture of cyclic PAS is a method for producing cyclic PAS by bringing a sulfidizing agent and a dihalogenated aromatic compound into contact with each other in an organic polar solvent. On the other hand, a method characterized in that the reaction mixture is heated beyond the reflux temperature at normal pressure using 1.25 liters or more of an organic polar solvent (see, for example, Patent Document 1). The reaction mixture obtained in this method contains cyclic PAS, linear PAS, and organic polar solvent, and other components include unreacted sulfiding agent, dihalogenated aromatic compound, water, by-product salt, and the like. There is also a case. Examples of methods for recovering the solution part from the reaction mixture include known methods such as separation by filtration, centrifugation, and decantation.

  These solid-liquid separation methods are easy to operate and relatively easy to scale up, but decantation tends to be expensive in terms of equipment costs compared to other separation operations. On the other hand, separation by filtration and centrifugation are easy to keep down relatively inexpensively in terms of equipment costs, etc., but if the filtration speed during solid-liquid separation is insufficient, the processing speed of the entire process is likely to be affected. When considering production efficiency, it is important to increase the efficiency of solid-liquid separation.

JP 2009-030012 A

  This invention solves the said subject at the time of scale-up, and makes it a subject to provide the method of collect | recovering cyclic PAS with high purity efficiently also in the production facility of cyclic PAS.

In response to the above problems, the present invention
1. A method of recovering (a) by solid-liquid separation from a mixture containing at least cyclic PAS (a), linear PAS (b), and organic polar solvent (c), wherein the boiling point is below the normal pressure of (c) The cyclic PAS (a) recovery method, wherein the liquid is transferred to a solid-liquid separator such that the required power for stirring applied to the mixture is 2.0 kWh / m ³ or less in the temperature range of
2. The cyclic PAS according to claim 1, wherein the cyclic PAS (a) is a compound represented by the following formula (1), wherein Ar is an arylene group, and a value of m is 2 to 50. The recovery method of (a),

3. The method for recovering cyclic PAS (a) according to claim 1 or 2, wherein the organic polar solvent (c) is an organic amide solvent,
4). The method for recovering cyclic PAS (a) according to any one of claims 1 to 3, wherein the organic polar solvent (c) is an aprotic solvent,
5. The mixture containing cyclic PAS (a), linear PAS (b), and organic polar solvent (c) may be further mixed with the second solvent (d), and the second solvent ( The method for recovering cyclic PAS according to any one of claims 1 to 4, wherein d) is a protic solvent,
6). The method for recovering cyclic PAS (a) according to any one of claims 1 to 5, wherein solid-liquid separation is performed using a filter medium having an air permeability of less than 5.0 cm ³ / cm ² · sec,
7. The method for recovering cyclic PAS (a) according to any one of claims 1 to 6, wherein solid-liquid separation is performed in a temperature range of 10 ° C to 200 ° C.
8). The method for recovering cyclic PAS according to any one of claims 1 to 7, wherein the solid-liquid separation is performed in an inert gas atmosphere.

  According to the present invention, it is possible to avoid a reduction in filtration speed due to clogging in the solid-liquid separation process at the time of scale-up, a reduction in cyclic PAS purity and a reduction in yield due to removal of filter cloth, and a high-purity cyclic polyarylene sulfide. A process that can be efficiently recovered can be achieved.

  Embodiments of the present invention will be described below.

(1) Sulfiding agent The sulfiding agent used in the present invention may be any sulfidizing agent as long as it can introduce a sulfide bond into a dihalogenated aromatic compound. For example, alkali metal sulfide, alkali metal hydrosulfide, and hydrogen sulfide may be used. Can be mentioned.

  Specific examples of the alkali metal sulfide include lithium sulfide, sodium sulfide, potassium sulfide, rubidium sulfide, cesium sulfide and a mixture of two or more thereof, among which lithium sulfide and / or sodium sulfide are preferable. Sodium sulfide is more 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 preferable to use such forms of alkali metal sulfides.

  Specific examples of the alkali metal hydrosulfide include, for example, lithium hydrosulfide, sodium hydrosulfide, potassium hydrosulfide, lithium hydrosulfide, rubidium hydrosulfide, cesium hydrosulfide, and mixtures of two or more thereof. Lithium hydrosulfide and / or sodium hydrosulfide are preferable, and sodium hydrosulfide is more preferably used.

  In addition, an alkali metal sulfide prepared in situ in a reaction system from an alkali metal hydrosulfide and an alkali metal hydroxide can also be used. Alternatively, an alkali metal sulfide prepared by previously contacting an alkali metal hydrosulfide and an alkali metal hydroxide can be used. These alkali metal hydrosulfides and alkali metal hydroxides can be used as hydrates or aqueous mixtures, or in the form of anhydrides. From the viewpoint of availability and cost of hydrates or aqueous mixtures. preferable.

  Furthermore, alkali metal sulfides prepared in situ in the reaction system from alkali metal hydroxides such as lithium hydroxide and sodium hydroxide and hydrogen sulfide can also be used. Further, alkali metal sulfides prepared by previously contacting alkali metal hydroxides such as lithium hydroxide and sodium hydroxide with hydrogen sulfide can also be used. Hydrogen sulfide can be used in any form of gas, liquid, and aqueous solution.

  In the present invention, the amount of the sulfidizing agent is subtracted from the actual charge when the loss of the sulfidizing agent partially occurs before the start of the reaction with the dihalogenated aromatic compound due to dehydration operation or the like. It shall mean the remaining amount.

  An alkali metal hydroxide and / or an alkaline earth metal hydroxide can be used in combination with the sulfidizing agent. Specific examples of the alkali metal hydroxide include sodium hydroxide, potassium hydroxide, lithium hydroxide, rubidium hydroxide, cesium hydroxide, and a mixture of two or more thereof. Specific examples of the metal hydroxide include, for example, calcium hydroxide, strontium hydroxide, barium hydroxide, and sodium hydroxide is preferably used.

  When an alkali metal hydrosulfide is used as the sulfidizing agent, it is particularly preferable to use an alkali metal hydroxide at the same time, but the lower limit is 0.80 mol for 1 mol of the alkali metal hydrosulfide. It is above, Preferably it is 0.85 mol or more, More preferably, it is 0.95 mol or more, More preferably, it is 1.005 mol or more. Moreover, an upper limit is 1.50 mol or less, Preferably it is 1.25 mol, More preferably, the range of 1.20 mol can be illustrated. When hydrogen sulfide is used as the sulfiding agent, it is particularly preferable to use an alkali metal hydroxide at the same time. The amount of the alkali metal hydroxide used in this case is 2.0 to 3.0 with respect to 1 mole of hydrogen sulfide. The range of mol, Preferably it is 2.01-2.50 mol, More preferably, it is 2.04-2.40 mol. Here, the cyclic PAS can be obtained in a high yield by setting the amount of the alkali metal hydroxide used within the above range, but the cyclic PAS produced is easily decomposed even if the amount is more than or less than the above range. The yield tends to decrease.

(2) Dihalogenated aromatic compound As the dihalogenated aromatic compound used in the production of the cyclic PAS of the present invention, p-dichlorobenzene, o-dichlorobenzene, m-dichlorobenzene, p-dibromobenzene, o- Dihalogenated benzene such as dibromobenzene, m-dibromobenzene, 1-bromo-4-chlorobenzene, 1-bromo-3-chlorobenzene, and 1-methoxy-2,5-dichlorobenzene, 1-methyl-2,5-di Dihalogenated aromatic compounds containing substituents other than halogen such as chlorobenzene, 1,4-dimethyl-2,5-dichlorobenzene, 1,3-dimethyl-2,5-dichlorobenzene and 3,5-dichlorobenzoic acid And so on. 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 two or more different dihalogenated aromatic compounds in combination in order to produce a cyclic PAS copolymer.

  The amount of the dihalogenated aromatic compound used is preferably in the range of 0.90 to 2.00 mol, more preferably in the range of 0.92 to 1.50 mol, per mol of the sulfur component of the sulfidizing agent. The range of .95 to 1.20 mol is more preferred. By setting the amount of dihalogenated aromatic compound in the above range, cyclic PAS can be obtained in high yield, but when the amount is less than the above range, the yield of cyclic PAS tends to decrease, When the amount is more than the range, the amount of low molecular weight linear PAS produced increases, and it tends to be difficult to recover cyclic PAS with high purity by the method described later.

(3) Organic polar solvent (c)
In the production of the cyclic PAS of the present invention, an organic polar solvent is used as a reaction solvent. Among them, an organic amide solvent is preferably used. Specific examples include N-alkylpyrrolidones such as N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone and N-cyclohexyl-2-pyrrolidone, caprolactams such as N-methyl-ε-caprolactam, An aprotic organic solvent typified by 3-dimethyl-2-imidazolidinone, N, N-dimethylacetamide, N, N-dimethylformamide, hexamethylphosphoric triamide, etc., and a mixture thereof, have a stable reaction. It is preferably used because it is expensive. Of these, N-methyl-2-pyrrolidone and 1,3-dimethyl-2-imidazolidinone are preferably used.

  In the present invention, the amount of the organic polar solvent used as a reaction solvent in the production of cyclic PAS is 1.25 liters or more, preferably 1.5 liters or more, more preferably, relative to 1 mole of the sulfur component of the sulfidizing agent. 2 liters or more. The upper limit of the amount used is not particularly limited, but from the viewpoint of more efficiently producing cyclic PAS, it is preferably 50 liters or less, more preferably 20 liters or less, with respect to 1 mole of the sulfur component of the sulfidizing agent, More preferably, it is 15 liters or less. Here, the amount of solvent used is based on the volume of the solvent under normal temperature and pressure. When the amount of the organic polar solvent used is increased, the selectivity of cyclic PAS production is improved. However, when the amount is too large, the production amount of cyclic PAS per unit volume of the reaction vessel tends to decrease. There is a tendency that the time required is longer. It is preferable to make it the usage-amount range of an organic polar solvent mentioned above from a viewpoint of making the production | generation selectivity of cyclic PAS and productivity compatible. In addition, the amount of the solvent used in the production of a general cyclic compound is very large in many cases, and the cyclic compound is often not efficiently obtained within the preferable amount range of the present invention. In the present invention, cyclic PAS can be efficiently obtained even under conditions where the amount of solvent used is relatively small compared to the case of production of a general cyclic compound, that is, even when the amount is not more than the above-mentioned preferred upper limit value of the amount of solvent used. The reason for this is not clear at the present time, but in the method of the present invention, the reaction is carried out above the reflux temperature of the reaction mixture, so that the reaction efficiency is very high and the raw material consumption rate is suitable for the production of the cyclic compound. I guess it is. Here, the usage amount of the organic polar solvent in the reaction mixture 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.

(4) Solvent (d)
In the present invention, a different second solvent (d) may be mixed with (c) an organic polar solvent containing (a) cyclic PAS and (b) linear PAS.

  The second solvent (d) used here is added to an organic solvent mixture containing (a) cyclic PAS and (b) linear PAS, and is preferably 50% by weight or more of cyclic PAS (a) in the mixture, preferably Is 70% or more, more preferably 90% or more, and even more preferably 95% or more as long as it has a property of recovering as a solid content. Therefore, the second solvent (d) needs to have a lower solubility in cyclic PAS and linear PAS than the organic solvent (c). Solvents having such characteristics are generally highly polar solvents, and the preferred solvent differs depending on the type of organic solvent (c) used, so there is no limitation. For example, water, methanol, ethanol, propanol, isopropanol, butanol, Examples include alcohols typified by hexanol, ketones typified by acetone and methyl ethyl ketone, and acetates typified by ethyl acetate and butyl acetate. Among these, water and alcohols, which are protic solvents, can be suitably used because they have particularly high polarity and low solubility of cyclic PAS. Among protic solvents, from the viewpoint of availability, economy, and ease of handling. Water, methanol and ethanol are preferable, and water is particularly preferable.

(5) Cyclic PAS (a)
The cyclic PAS in the present invention is a cyclic compound having a repeating unit of the formula:-(Ar-S)-as a main constituent unit, and preferably of the general formula (A) containing 80 mol% or more of the repeating unit. It is a compound.

  Here, examples of Ar can include units represented by the following general formulas (B) to (M), among which formulas (B) to (K) are preferable, and formulas (B) and (C) are preferred. More preferred is formula (B).

(In the formula, R1 and R2 are substituents selected from hydrogen, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, and a halogen group, and R1 and R2 are the same or different. May be.)

(In the formula, R1 and R2 are substituents selected from hydrogen, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, and a halogen group, and R1 and R2 are the same or different. May be.)

(In the formula, R1 and R2 are substituents selected from hydrogen, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, and a halogen group, and R1 and R2 are the same or different. May be.)

  In addition, in cyclic PAS, repeating units, such as said Formula (B)-Formula (M), may be included at random, may be included in a block, and any of those mixtures may be sufficient. Typical examples of these include cyclic polyphenylene sulfide, cyclic polyphenylene sulfide sulfone, cyclic polyphenylene sulfide ketone, cyclic random copolymers containing these, cyclic block copolymers, and mixtures thereof. . Particularly preferred cyclic PASs include p-phenylene sulfide units as the main structural unit.

Is a cyclic polyphenylene sulfide containing 80 mol% or more, particularly 90 mol% or more (hereinafter sometimes abbreviated as cyclic PPS).

  Although there is no restriction | limiting in particular in the repeating number m in the said (A) type of cyclic PAS, 2-50 are preferable, 2-25 are more preferable, and 3-20 can be illustrated as a still more preferable range. As will be described later, when the polyarylene sulfide prepolymer containing cyclic PAS is converted to a high degree of polymerization, it is preferable to perform heating at a temperature higher than the melting temperature of cyclic PAS, but when m increases Since the melt solution temperature of cyclic PAS tends to be high, m should be in the above range from the viewpoint that the polyarylene sulfide prepolymer can be converted to a high degree of polymerization at a lower temperature. Is advantageous.

  The cyclic PAS may be either a single compound having a single repeat number or a mixture of cyclic PASs having different repeat numbers, but a mixture of cyclic PAS having different repeat numbers is a single repeat. Use of a mixture of cyclic PASs having different repeating numbers tends to be lower than that of a single compound having a number, and is preferable because the temperature at the time of conversion to a high degree of polymerization can be further reduced.

(6) Wire PAS
The linear PAS in the present invention is a linear homopolymer or linear copolymer having a repeating unit of the formula:-(Ar-S)-as a main constituent unit, preferably containing 80 mol% or more of the repeating unit. is there. The linear PAS in the present invention may be any of a random copolymer, a block copolymer and a mixture thereof containing the above repeating unit. Typical examples of these include polyphenylene sulfide, polyphenylene sulfide sulfone, polyphenylene sulfide ketone, random copolymers thereof, block copolymers, and mixtures thereof. Particularly preferred PAS include polyphenylene sulfide (hereinafter sometimes abbreviated as PPS) containing 80 mol% or more, particularly 90 mol% or more of p-phenylene sulfide units as the main structural unit of the polymer, polyphenylene sulfide sulfone, polyphenylene. And sulfide ketone. The melt viscosity of various linear PAS in the present invention is not particularly limited, but the melt viscosity of a general linear PAS can be exemplified by a range of 0.1 to 1000 Pa · s (300 ° C., shear rate 1000 / sec). The range of 0.1 to 500 Pa · s is a preferable range from the viewpoint of availability. Further, the molecular weight of the linear PAS is not particularly limited, and general PAS can be used. The weight average molecular weight of such a PAS can be exemplified by 5,000 to 1,000,000, 500 to 500,000 are preferable, and 10,000 to 100,000 are more preferable. In general, the lower the weight average molecular weight, the higher the solubility in an organic polar solvent. Therefore, there is an advantage that the time required for the reaction can be shortened, but within the above-mentioned range, it can be used without any substantial problem. The production method of such a linear PAS is not particularly limited, and any production method can be used. However, an aromatic compound or thiophene containing at least one nucleus-substituted halogen and an alkali metal monosulfide can be used. In a polar organic solvent at an elevated temperature, preferably by contacting a sulfiding agent with a dihalogenated aromatic compound in an organic polar solvent. In addition, molded products using PAS produced by these methods, molding waste, waste plastics, off-spec products, and the like can be widely used. In general, the production of a cyclic compound also includes the present invention, and is a competitive reaction between the production of a cyclic compound and the production of a linear compound. Therefore, in a method for producing cyclic PAS, In addition to cyclic PAS, linear PAS is generated as a by-product. In the present invention, such a by-product linear PAS can also be used as a raw material without any problem. For example, a sulfiding agent and a dihalogenated aromatic compound represented by Patent Document 4 described above can be used as a sulfurizing agent. Obtained by separating cyclic PAS from a PAS mixture containing cyclic PAS and linear PAS obtained by heating and reacting with 1.25 liters or more of an organic polar solvent per mole of component. The method using the obtained linear PAS is a particularly preferable method. In addition, an organic polar solvent of 1.25 liters or more and 50 liters or less is used for the linear PAS typified by the above-mentioned Patent Document 1, a sulfidizing agent, and a dihalogenated aromatic compound with respect to 1 mol of a sulfur component in the reaction mixture. A method using linear PAS obtained by separating cyclic PAS from a PAS mixture containing cyclic PAS and linear PAS obtained by heating and reaction is also a preferable method. Further, the linear PAS produced by the practice of the present invention, i.e., at least 0.9 moles of dihalogenated aromatic compound per mole of sulfur component of the linear PAS, sulfidizing agent, organic polar solvent, and sulfiding agent. The reaction mixture is heated to react, and then the total amount including the dihalogenated aromatic compound used in the reaction is 0.9 to 2 per mole of sulfur component of the sulfiding agent used in the reaction. It was obtained by adding a dihalogenated aromatic compound to 0.0 mol and heating the reaction in an organic polar solvent of 1.25 liters or more per 1 mol of the sulfur component in the reaction mixture. It is a further preferred method to use linear PAS obtained by separating cyclic PAS from a PAS mixture comprising cyclic PAS and linear PAS. A. Conventionally, a cyclic compound, a linear compound by-produced in the production of cyclic PAS, and linear PAS have been discarded as having no utility value. Therefore, in the production of the cyclic compound, there are problems that the amount of waste caused by the by-product linear compound is large and the yield relative to the raw material monomer is low. In the present invention, this byproduct linear PAS can be used as a raw material, which is significant in terms of enabling a significant reduction in the amount of waste and a dramatic improvement in the yield relative to the raw material monomer. It is. In addition, there is no restriction | limiting in particular in the form of linear PAS, It is also possible to use it in the state containing the organic polar solvent which is a reaction solvent, and powder-form, a granular form, a pellet form of a dry state may be sufficient, It is also possible to use in a state containing a third component that does not essentially inhibit the reaction. Examples of such a third component include inorganic fillers and alkali metal halides. Here, the alkali metal halide includes any combination of alkali metals, ie, lithium, sodium, potassium, rubidium and cesium, and halogens, ie, fluorine, chlorine, bromine, iodine and astatine. Examples thereof include lithium chloride, sodium chloride, potassium chloride, lithium bromide, sodium bromide, potassium bromide, lithium iodide, sodium iodide, potassium iodide, cesium fluoride, and the like. Preferable examples include alkali metal halides produced by reaction with dihalogenated aromatic compounds. Alkali metal halides resulting from combinations of sulfidizing agents and dihalogenated aromatic compounds that are generally readily available include lithium chloride, sodium chloride, potassium chloride, lithium bromide, sodium bromide, potassium bromide and sodium iodide. And sodium chloride, potassium chloride, sodium bromide, and potassium bromide can be exemplified as preferable examples, and sodium chloride is more preferable. It is also possible to use linear PAS in the form of a resin composition containing an inorganic filler or an alkali metal halide.

(7) Method for Producing Cyclic PAS In the present invention, a cyclic PAS is produced by contacting a sulfidizing agent and a dihalogenated aromatic compound in an organic polar solvent.

  In the production of the cyclic PAS of the present invention, the amount of water in the reaction mixture needs to be less than 0.8 mol, preferably less than 0.7 mol, per 0.6 mol of sulfur component, More preferably, it is less than 0.5 mol, and even more preferably less than 0.5 mol. Moreover, there is no lower limit of the water content in the reaction mixture, and it is preferable that it is close to 0. However, 0.05 mole or more per 1 mole of sulfur component in the reaction mixture can be exemplified as a practical lower limit in carrying out the present invention. Regarding the water content in the reaction mixture during the production of the cyclic PAS, it is specified in the above-mentioned Patent Document 3 that 0.8 mol to 20 mol is preferable per 1 mol of the sulfur component in the reaction mixture. Even if the water content is less than the lower limit of the amount of water in the literature, that is, less than 0.8 mol, it is possible not only to perform a sufficient reaction at the same reaction concentration, reaction temperature and reaction time, but also the yield of cyclic PAS. The inventors have found that the selectivity can be improved and have completed the present invention. Furthermore, when the amount of water in the reaction mixture exceeded the preferred range of the present invention, coloring of the reaction liquid and adhesion of the colored material to the reactor were remarkable, but by making the amount of water within the preferred range of the present invention, These coloring problems were greatly improved, and not only the quality of the obtained cyclic PAS was improved, but also the washing operation of the reactor could be reduced.

  The amount of water in the reaction mixture in the present invention refers to each component including the sulfidizing agent, dihalogenated aromatic compound, and organic polar solvent charged in the reaction system, as well as other components when other components are charged. Or the amount of water removed from the total amount of water when water is removed from the reaction system by an additional operation such as dehydration. The amount of water is calculated by subtracting, and water generated during the mixing and reaction of the above components is not considered. As a method for bringing the water content in the reaction mixture into the above preferred range, for example, the above-mentioned various components having anhydrous or low water content, the total water content of each component is 0.8 per mole of sulfur component of the sulfidizing agent. A method used as a combination of less than a mole can also be exemplified as a preferred method. In addition, when the total water content of the above components is 0.8 mol or more per 1 mol of the sulfur component of the sulfidizing agent, a dehydration step is provided in advance to reduce the water content of each component to a desired range. It is also possible to employ a method of using, or a method of mixing and reacting the above components with a large amount of water while dehydrating. In general, dihalogenated aromatic compounds and organic polar solvents with a sufficiently low water content are relatively readily available, whereas sulfidizing agents such as alkali metal sulfides have an oxygen content of 0.1 per mole of sulfur component. Hydrates or aqueous mixtures containing 8 moles or more of water are generally cheaper and more readily available. Therefore, from the viewpoint of availability and cost, it is preferable to use these hydrates or aqueous mixtures as sulfiding agents. In this case, the water content in the reaction mixture is the same as the water content of the dihalogenated aromatic compound and the organic polar solvent. Regardless, since it becomes 0.8 mol or more per 1 mol of sulfur component of the sulfidizing agent, it is necessary to provide a step of dehydration in order to adjust the water content in the reaction mixture to the above preferred range.

  In the dehydration step in the present invention, each of the sulfidizing agent, dihalogenated aromatic compound and organic polar solvent can be dehydrated individually or as a mixture of two or more. The dehydration method in the dehydration step is not particularly limited as long as it can be adjusted within the preferable range of water content, but for example, the following liquid removal method is preferably employed. That is, a mixture of at least a water-containing sulfidizing agent and an organic polar solvent is preferably prepared in an inert gas atmosphere at room temperature to 150 ° C., preferably from room temperature to 100 ° C., and at 150 ° C. under normal pressure or reduced pressure. As mentioned above, it is possible to exemplify a method in which the temperature is raised to 170 ° C. or more, more preferably 200 ° C. or more, and water is distilled off so that the water content is less than 0.8 mol per mol of sulfur component of the sulfidizing agent. . In addition, it is 250 degreeC as a preferable upper limit of the temperature which distills off the said organic polar solvent and a water | moisture content. In addition, the amount of the organic polar solvent used in the liquid removal method is preferably 0.1 to 1 liter, more preferably 0.13 to 0.8 liter, and more preferably 0.16 to 0.001 per mole of the sulfur component of the sulfiding agent. More preferably 6 liters. Within this range, metal elution from the container tends to decrease when a metal container is used for the reaction, and reduction of metal impurities in the resulting cyclic PAS can be expected. Further, in the dehydration step, the distillation may be carried out with stirring, preferably through an inert gas stream, and an azeotropic component such as toluene may be added. It may be distilled off. Further, a rectifying column may be provided for the purpose of selectively distilling off water.

  After preparing the reaction mixture by mixing the dehydration component prepared in the above dehydration step with other anhydrous or low moisture components essential for the production of the cyclic PAS of the present invention in the reaction step, It is possible to produce cyclic PAS by reaction, and the reaction step is preferably carried out continuously with the dehydration step. Here, the reaction may be carried out in the same reactor as the dehydration step, or the dehydration component prepared in the dehydration step may be transferred to a different reactor and mixed with other components, but prepared in the dehydration step. A method of transferring the dehydrated components to different reactors is preferable, and a method of transferring the dehydrated components for a plurality of reaction steps adjusted in the dehydration step into smaller portions is more preferable, whereby the dehydration step is involved in the production process of cyclic PAS Since the time can be shortened, there is an advantage that productivity is improved.

  In addition to the essential components, a third component that does not significantly inhibit the reaction and a third component that has an effect of accelerating the reaction can be added to the reaction mixture. Although there is no restriction | limiting in particular in the method of performing reaction, It is preferable to carry out on stirring conditions.

  In the production of the cyclic PAS of the present invention, the cyclic PAS is produced by heating the reaction mixture comprising the above components. The reaction temperature in the production of the cyclic PAS of the present invention is not particularly limited, but preferably exceeds the reflux temperature under normal pressure, and this temperature varies depending on the type and amount of the components in the reaction mixture, and thus is unique. However, it is usually 120 to 350 ° C, preferably 180 to 320 ° C, more preferably 220 to 310 ° C, still more preferably 225 to 300 ° C, and still more preferably 240 to 280 ° C. Here, the normal pressure is a pressure in the vicinity of the standard state of the atmosphere, and is an atmospheric pressure condition in which the temperature is approximately 25 ° C. and the absolute pressure is approximately 101 kPa. The reflux temperature is a temperature at which the liquid component of the reaction mixture repeats boiling and condensation. In the present invention, it is preferable to heat the reaction mixture above the reflux temperature under normal pressure. As a method for bringing the reaction mixture into such a heated state, for example, a method of reacting the reaction mixture under a pressure exceeding normal pressure, A method of heating the reaction mixture in a sealed container can be exemplified. In this preferable temperature range, a higher reaction rate can be obtained, the reaction tends to be uniform and easy to proceed, and cyclic PAS tends to be efficiently obtained. The reaction may be 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.

  The reaction time depends on the type and amount of the raw material used or the reaction temperature and cannot be defined unconditionally. However, it is preferably 0.1 hour or longer, more preferably 0.5 hour or longer. By setting it as this preferable time or more, since unreacted raw material components can be reduced sufficiently, the produced cyclic PAS tends to be easily recovered. On the other hand, although there is no particular upper limit to the reaction time, the method of the present invention has a feature that an extremely high reaction rate can be easily obtained. Therefore, the reaction proceeds sufficiently even within 40 hours, preferably within 10 hours, more preferably 6 Can be used within hours.

  In the production of the cyclic PAS of the present invention, the pressure at which the reaction mixture is heated cannot be uniquely defined because it varies depending on the raw materials constituting the reaction mixture and its composition, reaction temperature, etc. The gauge pressure is 1 MPa or less. In the present invention, it is preferable to exceed the reflux temperature of the reaction mixture under normal pressure. Examples of the method for bringing the reaction mixture into such a heated state include a method of reacting the reaction mixture under a pressure exceeding normal pressure, and a reaction. Since the method of heating a mixture in a closed container can be exemplified, the lower limit of the preferable pressure is a pressure exceeding normal pressure. That is, as a specific preferable pressure, the gauge pressure is 0.05 MPa to 1 MPa, more preferably 0.1 MPa to 0.8 MPa, further preferably 0.2 MPa to 0.6 MPa, and particularly preferably 0.2 MPa to 0.5 MPa. Can be illustrated. In such a preferable pressure range, the time required for producing the cyclic PAS tends to be shortened. In general, when the pressure at which the reaction mixture is heated exceeds 1 MPa, expensive pressure-resistant production equipment for cyclic PAS that can withstand such pressure is required, but in such a preferable pressure range, equipment for production of cyclic PAS is required. Cost can be reduced and safety is high. From this point of view, when producing cyclic PAS using general-purpose equipment, it is particularly preferable that the pressure when heating the reaction mixture is 0.5 MPa or less. Here, the gauge pressure is a relative pressure based on atmospheric pressure, and is equivalent to a pressure value obtained by subtracting atmospheric pressure from absolute pressure.

  In the production of the cyclic PAS of the present invention, it is also possible to continue the reaction by adding a sulfidizing agent and a dihalogenated aromatic compound at an optional stage in which the reaction is continued for a desired time and the charged raw materials are reduced. is there. It is important to consider the amount of the sulfidizing agent in the reaction mixture before the addition, and the sulfur atom 1 of the sulfidizing agent in the reaction mixture after the addition of the sulfidizing agent is important. It is strongly desired to perform addition within the range where the organic polar solvent is 1.25 liters or more and the water content is less than 0.8 mol with respect to mol. In the method of the present invention, since the sulfidizing agent is consumed by reacting with the dihalogenated aromatic compound, the conversion rate of the sulfidizing agent can be estimated from the conversion rate of the dihalogenated aromatic compound. It is possible to calculate the amount of the sulfiding agent in the reaction mixture from the conversion rate of the sulfiding agent.

The conversion rate of the dihalogenated aromatic compound (hereinafter sometimes abbreviated as DHA) is a value calculated by the following formula. 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 sulfidizing agent, 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%.

  As described above, the addition of the sulfidizing agent and the dihalogenated aromatic compound allows an optional stage in which the charged raw materials are reduced, but a stage in which the conversion rate of DHA is 50% or more is preferable. 70% or more is more preferable, and cyclic PAS can be obtained more efficiently by adding at such a stage.

  There is no limit to the number of times such addition of the sulfidizing agent and the dihalogenated aromatic compound is performed, but usually the sum of the sulfidizing agent and the added sulfidizing agent in the reaction system at the start of the reaction A preferable range is an amount of up to 10 moles per liter of the organic polar solvent based on the sulfur atom of the sulfiding agent. Here, the addition of the sulfidizing agent and the dihalogenated aromatic compound is a preferable method because it has the effect of increasing the amount of the product in the reaction mixture and can increase the yield of cyclic PAS per unit volume.

  In addition, when the water content in the reaction mixture changes due to the addition of the sulfidizing agent and the dihalogenated aromatic compound, it is possible to perform an additional operation so that the above-mentioned preferable water content is obtained. It is also desirable to remove an arbitrary amount of water from the reaction mixture during and after the addition. In the removal of water, when components other than water are removed from the reaction mixture, a sulfidizing agent, a dihalogenated aromatic compound, and an organic polar solvent can be further added as necessary. The operation of returning the components to the reaction mixture may be performed again.

  In the production of the cyclic PAS of the present invention, various known polymerization methods and reaction methods such as a batch method and a continuous method can be employed. Further, the atmosphere in the production is preferably a non-oxidizing atmosphere, and it is preferably carried out in an inert gas atmosphere such as nitrogen, helium, and argon. In particular, from the viewpoint of economy and ease of handling, the nitrogen atmosphere is preferable. preferable. In the present invention, the upper limit of the preferable pressure when heating the reaction mixture is 1 MPa or less in terms of gauge pressure, and pressurization with an inert gas may be performed within a range not exceeding this pressure.

(8) Method for recovering cyclic PAS In the production of cyclic PAS of the present invention, it is also possible to separate and recover cyclic PAS from the reaction mixture obtained by the reaction described above. When the reaction mixture obtained by the reaction contains cyclic PAS and linear PAS in an organic polar solvent, and other components include unreacted sulfidizing agent, dihalogenated aromatic compound, water, by-product salt, etc. There is also.

  In the above, as a method for recovering cyclic PAS, a method for recovering cyclic PAS from this mixture after first obtaining a PAS mixture containing cyclic PAS and linear PAS is exemplified, but the recovery method is limited to this. is not. Another specific example of the cyclic PAS recovery method is shown below.

  When the reaction mixture obtained in the present invention contains cyclic PAS, linear PAS and organic polar solvent, and other components include unreacted sulfating agent, dihalogenated aromatic compound, water, by-product salt, etc. As described above, in this reaction mixture, cyclic PAS tends to be dissolved in an organic polar solvent in a wide temperature range. On the other hand, linear PAS differs greatly in dissolution behavior from cyclic PAS. Specifically, most of the linear PAS tends to exist as a solid in the reaction mixture in a temperature range of 200 ° C. or lower.

  Therefore, by using such a difference in dissolution behavior in the reaction mixture of cyclic PAS and linear PAS, it is possible to separate cyclic PAS and linear PAS by simple solid-liquid separation. More specifically, the upper limit of the temperature range in which cyclic PAS and linear PAS can be separated by solid-liquid separation is 200 ° C. or lower, more preferably 150 ° C. or lower, and still more preferably 120 ° C. or lower. On the other hand, as a minimum temperature, 10 degreeC or more can be illustrated, 20 degreeC or more is preferable, 50 degreeC or more is more preferable, and 80 degreeC or more is still more preferable. Below this preferred upper temperature limit, the linear PAS contained in the reaction mixture tends to exist as a solid content, and the above-mentioned preferred linear PAS having a preferred weight average molecular weight tends to become a solid content under these conditions. On the other hand, in this preferred temperature range, cyclic PAS in the reaction mixture has a strong tendency to be soluble in an organic polar solvent, and in particular, cyclic PAS in the preferred range in which the number of repeating units m of cyclic PAS described above is under these conditions. Strong tendency to dissolve in organic polar solvents. Above the exemplified lower limit temperature, the viscosity of the reaction mixture tends to be low, the solid-liquid separation operation is easy, and the separation between the solid component and the solution component tends to be excellent.

Maintaining excellent separability is desirable even when assuming production facilities. In particular, when batch or continuous production operation is performed in a production facility where the volume of a plurality of reaction kettles is 20 L to 300 m ³ , the vessel must be stirred by a stirrer or a pump to prevent particle settling. In that case, it is desirable to reduce as much as possible the physical load on the generated particles by a stirrer, baffle plate, pump impeller and the like. In particular the slurry temperature is subjected to the following conditions 130 ° C., can be exemplified the stirring power requirement 2.0kWh / ^{m 3} or less for the slurry per 1 m ^3, preferably 1.0kWh / ^{m 3} or less, is 0.5kWh / ^{m 3} or less More preferred is 0.2 kWh / m ³ or less. Further, the lower limit is preferably 0.001 kWh / m ³ or more. In order to keep the load within the exemplified range, for example, the stirring standby time in the particle precipitation state is shortened, the stirring blade is rotated at a low speed, a reaction tank without a baffle plate is used, and the pump has a liquid feeding load such as a rotary pump. The method of making it a small type can be exemplified. If the agitation is not carried out, the precipitated PAS component will settle down, which may cause troubles such as clogging of the transfer pump and piping. The solid content is crushed and the particle size tends to be small. Therefore, in the subsequent solid-liquid separation operation, the separation between the solid component and the solution component is deteriorated, which may affect the processing speed of the entire process, and the pulverized and refined particles pass through the filter cloth and pass through the filtrate side. It is thought that this leads to a decrease in purity and yield.

Further, the filter medium for reducing the purity and yield reduction due to removal of the filter cloth while maintaining high separability is not required to be deteriorated by the organic polar solvent (c). For example, SUS metal filter medium or polyester While such manufacturing filter cloth and the like, the air permeability is 5.0cm ³ / ^cm 2 · sec or less. ^examples, 3.0cm ^{3 /} cm 2 · sec or less. Further, the lower limit can be exemplified by 0.001 cm ³ / cm ² · sec or more. The air permeability is a method defined by JIS L1096 air permeability A method (Flangeal type method), and measures the flow rate of gas passing through the filter cloth when the pressure difference becomes 125 Pa.

  The solution component obtained by solid-liquid separation of the reaction mixture described above, that is, the filtrate component (which may contain a solid component depending on the temperature) includes cyclic PAS. If desired, the organic polar solvent can be removed from the filtrate components to recover it as a solid containing cyclic PAS. Examples of the method for removing the organic polar solvent include a method of removing by distillation, a method of contacting with a second solvent miscible with the organic polar solvent, and the like. As a specific method of removing by distillation, a method of heating the filtrate component to preferably 20 to 250 ° C, more preferably 40 to 200 ° C, still more preferably 100 to 200 ° C, and still more preferably 120 to 200 ° C. It can be illustrated. It is possible to efficiently remove the organic polar solvent by performing this heating under reduced pressure or under an air stream, and further under stirring. In addition, it is preferable to perform the atmosphere at the time of heating in non-oxidizing atmosphere, and it exists in the tendency which can suppress decomposition | disassembly, coloring, bridge | crosslinking, etc. of cyclic PAS by this. Here, the non-oxidizing atmosphere is an atmosphere having a gas phase oxygen concentration of 5% by volume or less, preferably 2% by volume or less, more preferably an oxygen-free atmosphere, that is, an inert gas such as nitrogen, helium or argon. It indicates a gas atmosphere, and among these, a nitrogen atmosphere is particularly preferred from the viewpoint of economy and ease of handling. As a specific method for obtaining cyclic PAS by solvent replacement of the filtrate component with the second solvent (d), the second solvent (d) in which the cyclic PAS does not dissolve or the cyclic PAS hardly dissolves. A method of recovering a solid component containing cyclic PAS by bringing it into contact with can be exemplified. As a more specific method of contacting with the second solvent (d), it is possible to exemplify adopting a method shown in (7) described later.

(9) Other post-treatments The cyclic PAS thus obtained has a sufficiently high purity and can be suitably used for various applications. However, the post-treatment described below is additionally applied to further increase the purity. Cyclic PAS can be obtained.
The cyclic PAS obtained by the operations up to (6) above may contain an impurity component contained in the PAS mixture depending on the characteristics of the solvent used. Impurities are dissolved in cyclic PAS containing such a small amount of impurities, but cyclic PAS is not dissolved or contacted with a second solvent (d) that is difficult to dissolve cyclic PAS to select impurity components. In many cases.

  The pressure of the reaction system when the cyclic PAS mixture is brought into contact with the second solvent (d) is preferably normal pressure or slight pressure, and particularly preferably normal pressure. The reaction system of such pressure is a member for constructing it. Has the advantage of being inexpensive. From this point of view, it is desirable that the reaction system pressure avoid pressurizing conditions that require an expensive pressure vessel. Preferred solvents as the second solvent (d) are those that do not substantially cause undesirable side reactions such as cyclic PAS decomposition and crosslinking, such as methanol, ethanol, propanol, butanol, pentanol, ethylene glycol, Alcohol / phenolic solvents such as propylene glycol, phenol, cresol, polyethylene glycol, hydrocarbon solvents such as pentane, hexane, heptane, octane, cyclohexane, cyclopentane, acetone, methyl ethyl ketone, diethyl ketone, methyl isobutyl ketone, methyl butyl ketone Ketone solvents such as acetophenone, methyl acetate, ethyl acetate, pentyl acetate, octyl acetate, methyl butyrate, ethyl butyrate, pentyl butyrate, methyl salicylate, ethyl formate, etc. Examples of the ester solvent and water include methanol, ethanol, propanol, butanol, pentanol, ethylene glycol, propylene glycol, pentane, hexane, heptane, octane, cyclohexane, cyclopentane, acetone, methyl acetate, ethyl acetate, Water is preferable, and methanol, ethanol, propanol, ethylene glycol, pentane, hexane, heptane, octane, cyclohexane, acetone, ethyl acetate, and water are particularly preferable. These solvents can be used as one kind or a mixture of two or more kinds.

  The temperature at which the cyclic PAS is brought into contact with the second solvent (d) is not particularly limited, but the upper limit temperature is preferably set to the reflux condition temperature under normal pressure of the second solvent (d) to be used. When using the preferable 2nd solvent (d), 20-100 degreeC can be illustrated as a preferable temperature range, for example, More preferably, 25-80 degreeC can be illustrated.

  The time for which the cyclic PAS is brought into contact with the second solvent (d) varies depending on the type of solvent used, the temperature, etc., and thus cannot be uniquely limited. For example, it can be exemplified by 1 minute to 50 hours, and within such a time range. Thus, the impurities in the cyclic PAS tend to be sufficiently dissolved in the second solvent (d).

  As a method of bringing the cyclic PAS into contact with the second solvent (d), a method of stirring and mixing the solid cyclic PAS and the second solvent (d) as necessary, cyclic PAS on various filters A method in which impurities are dissolved in the second solvent (d) at the same time when the second solvent (d) is showered on the solid, a method using Soxhlet extraction of the solid cyclic PAS using the second solvent (d), , Using a method in which a cyclic PAS in solution or a cyclic PAS slurry containing a solvent is brought into contact with the second solvent (d) to precipitate the cyclic PAS in the presence of the second solvent (d). Can do. Among them, the method of bringing the cyclic PAS slurry containing the solvent into contact with the second solvent (d) is an effective method because the cyclic PAS obtained after the operation has a high purity.

When the second solvent (d) is brought into contact with the mixture containing the cyclic PAS, it is necessary to sufficiently mix it, so that it is desirable to make the system uniform. Usually, in order to make the system uniform in a production facility where the volume of the reaction kettle is 20 L to 300 m ³ , the tank must be stirred by a stirrer or a pump. it is desirable to reduce as much as possible the physical load on the particles produced by, it can exemplified stirring power requirement 2.0kWh / ^{m 3} or less for the slurry per 1 m ^3, preferably 1.0kWh / ^{m 3} or less, 0.5KWh / M ³ or less is more preferable, and 0.2 kWh / m ³ or less is more preferable. In order to keep the load within the exemplified range, for example, the stirring standby time in the particle precipitation state is shortened, the stirring blade is rotated at a low speed, a reaction tank without a baffle plate is used, and the pump has a liquid feeding load such as a rotary pump. The method of making it a small type can be exemplified. Without stirring, the second solvent (d) is not sufficiently mixed and particle formation occurs locally, so that the particle diameter tends to be non-uniform, and coarse particles are produced. Although it is considered that problems in terms of operation and maintenance occur such as adhering to the reactor, when the stirring is continued at a power higher than this preferable stirring power, the cyclic PAS precipitated as a solid content is pulverized and particles The diameter tends to be small. For this reason, in the subsequent solid-liquid separation operation, the separation between the solid component and the solution component may deteriorate, which may affect the processing speed of the entire process, and the pulverized particles pass through the filter cloth and move to the filtrate side. As a result, the yield may be reduced.

Further, the filter medium for reducing the purity and yield reduction due to removal of the filter cloth while maintaining high separability is not required to be deteriorated by the organic polar solvent (c). For example, SUS metal filter medium or polyester While such manufacturing filter cloth and the like, the air permeability is 5.0cm ³ / ^cm 2 · sec or less. ^examples, 3.0cm ^{3 /} cm 2 · sec or less. Further, the lower limit can be exemplified by 0.001 cm ³ / cm ² · sec or more. The air permeability is a method defined by JIS L1096 air permeability A method (Flangeal type method), and measures the flow rate of gas passing through the filter cloth when the pressure difference becomes 125 Pa.

  After contacting the cyclic PAS with the second solvent (d), it is possible to recover the solid cyclic PAS using a known solid-liquid separation method. Examples of the solid-liquid separation method include separation by filtration, centrifugation, and decantation. If impurities still remain in the cyclic PAS obtained after solid-liquid separation, it is also possible to contact the cyclic PAS with the second solvent (d) again to further remove the impurities. .

(10) Properties of the cyclic PAS of the present invention The cyclic PAS thus obtained usually has a high purity containing 50% by weight or more, preferably 70% by weight or more, more preferably 80% by weight or more of the cyclic PAS. Therefore, it has high utility value even industrially having characteristics different from generally obtained linear PAS. In addition, the cyclic PAS obtained by the production method of the present invention is characterized in that m in the formula (A) is not single, and the formula (A) having m different from m = 4 to 50 is easily obtained. . Here, a preferable range of m is 4 to 25, and more preferably 4 to 20. When m is within this range, as described later, when used as a raw material for obtaining cyclic PAS, the polymerization reaction tends to proceed and a high molecular weight product tends to be easily obtained. The reason for this is not clear at present, but it is assumed that cyclic PAS in this range has a large bond distortion due to the cyclic nature of the molecule, and is likely to have a high molecular weight during polymerization.

  In addition, since cyclic PAS having a single m is obtained as a single crystal, it has a very high melting temperature. However, in the present invention, cyclic PAS is easy to obtain a mixture having different m, and thus melting of cyclic PAS There is a feature that the temperature is low, which expresses an excellent feature that, for example, the heating temperature when the cyclic PAS is melted and used can be lowered.

(11) Resin composition blended with cyclic PAS of the present invention The cyclic PAS obtained according to the present invention can be blended with various resins and used, and a resin composition blended with such a cyclic PAS. Has a strong tendency to exhibit excellent fluidity during melt processing, and tends to have excellent residence stability. Such improved properties, particularly fluidity, express the characteristics of excellent melt processability even when the heating temperature during melt processing of the resin composition is low, so that extrusion molding of injection molded products, fibers, films, etc. This is a great merit in that it improves the melt processability when processed into a product. The reason why such improvement in properties is manifested when cyclic PAS is blended is not clear, but because of the specificity of cyclic PAS structure, that is, the cyclic structure, it is compact compared to ordinary linear compounds. It is assumed that the entanglement with various resins that are matrixes tends to be reduced, that it acts as a plasticizer for various resins, and that the entanglement between matrix resins is also suppressed. .

  Although there is no restriction | limiting in particular in the compounding quantity at the time of mix | blending cyclic PAS with various resin, 0.1-50 weight part of cyclic PAS of this invention is preferable with respect to 100 weight part of various resin, Preferably it is 0.5-20. By blending parts by weight, more preferably 0.5 to 10 parts by weight, it is possible to obtain a remarkable improvement in characteristics.

  Moreover, it is also possible to mix | blend a fibrous and / or non-fibrous filler with the said resin composition as needed, The compounding quantity is 0.5 to 100 weight part of said various resin. A range of 400 parts by weight, preferably 0.5 to 300 parts by weight, more preferably 1 to 200 parts by weight, and even more preferably 1 to 100 parts by weight can be exemplified, and thereby mechanical strength while maintaining excellent fluidity. Tends to be improved. As the kind of filler, any filler such as fibrous, plate-like, powdery, and granular can be used. Specific examples of these fillers include glass fibers, talc, wollastonite, and layered silicates such as montmorillonite and synthetic mica, with glass fibers being particularly preferable. The type of glass fiber is not particularly limited as long as it is generally used for reinforcing a resin, and can be selected from, for example, a long fiber type, a short fiber type chopped strand, a milled fiber, or the like. Moreover, said filler can also be used in combination of 2 or more types. The surface of the filler used in the present invention can be used by treating the surface with a known coupling agent (for example, silane coupling agent, titanate coupling agent, etc.) or other surface treatment agents. . The glass fiber may be coated or bundled with a thermoplastic resin such as an ethylene / vinyl acetate copolymer, or a thermosetting resin such as an epoxy resin.

  Moreover, in order to maintain the thermal stability of the resin composition, it is possible to include one or more heat-resistant agents selected from phenolic and phosphorus compounds. The blending amount of the heat-resistant agent is preferably 0.01 parts by weight or more, particularly preferably 0.02 parts by weight or more with respect to 100 parts by weight of the various resins from the viewpoint of heat resistance improvement effect. From this viewpoint, it is preferably 5 parts by weight or less, particularly preferably 1 part by weight or less. In addition, it is particularly preferable to use a phenolic compound and a phosphorus compound in combination because of their large heat resistance, heat stability, and fluidity retention effect.

  Further, the resin composition includes the following compounds, that is, coupling agents such as organic titanate compounds and organic borane compounds, polyalkylene oxide oligomer compounds, thioether compounds, ester compounds, and organic phosphorus compounds. Plasticizers such as talc, kaolin, organophosphorus compounds, polyether ether ketone and other crystal nucleating agents, montanic acid waxes, metal soaps such as lithium stearate and aluminum stearate, ethylenediamine, stearic acid and sebacic acid heavy compounding Normal additives such as lubricants, mold release agents such as silicone compounds, anti-coloring agents such as hypophosphite, and other lubricants, UV inhibitors, coloring agents, flame retardants, and foaming agents. . All of the above compounds tend to exhibit their effects effectively when added in an amount of less than 20 parts by weight, preferably 10 parts by weight or less, more preferably 1 part by weight or less, based on 100 parts by weight of the various resins.

  The method for producing the resin composition comprising the cyclic PAS as described above is not particularly limited. For example, the cyclic PAS, various resins, and other fillers and various additives as necessary may be added in advance. After blending, melting and kneading with a generally known melt mixer such as a single screw or twin screw extruder, Banbury mixer, kneader, mixing roll, etc. above the melting point of various resins and cyclic PAS, solvent after mixing in the solution Exclusion methods are used. Here, when the cyclic PAS is a simple substance of the cyclic PAS, that is, when m of the formula (A) is a single one, or when a mixture of different m is used having a high crystallinity and a high melting point. In this method, the cyclic PAS is dissolved in a solvent in which the cyclic PAS is dissolved and supplied in advance, and the solvent is removed during melt kneading. The crystallization is suppressed by quenching the cyclic PAS once it has been melted at or above its melting point. A method of supplying an amorphous material or a method of setting a premelter to be equal to or higher than the melting point of the cyclic PAS, melting only the cyclic PAS in the premelter, and supplying the melt as a melt can be employed.

  Here, there are no particular limitations on the various resins in which the cyclic PAS is blended, and application to thermoplastic resins such as crystalline resins and amorphous resins, and thermosetting resins is also possible.

  Specific examples of the crystalline resin include, for example, polyolefin resins such as polyethylene resin, polypropylene resin, and syndiotactic polystyrene, polyvinyl alcohol resin, polyvinylidene chloride resin, polyester resin, polyamide resin, polyacetal resin, polyphenylene sulfide resin, Examples include polyetheretherketone resins, polyetherketone resins, polyketone resins, polyimide resins, and copolymers thereof, which may be used alone or in combination of two or more. Of these, polyphenylene sulfide resins, polyamide resins, and polyester resins are preferable in terms of heat resistance, moldability, fluidity, and mechanical properties. Moreover, a polyester resin is preferable from the viewpoint of transparency of the obtained molded product. When a crystalline resin is used as the various resins, there is a tendency to improve the crystallization characteristics in addition to the improvement in fluidity described above. In addition, it is particularly preferable to use polyphenylene sulfide resin as various resins. In this case, it is said that the improvement of the crystallinity and the effect of these effects are significantly suppressed in the injection molding as well as the fluidity. Features tend to develop easily.

  The amorphous resin is not particularly limited as long as it is an amorphous resin that can be melt-molded. However, in terms of heat resistance, the glass transition temperature is preferably 50 ° C. or higher, and is 60 ° C. or higher. Is more preferable, it is more preferable that it is 70 degreeC or more, and it is especially preferable that it is 80 degreeC or more. The upper limit is not particularly limited, but is preferably 300 ° C. or less, more preferably 280 ° C. or less from the viewpoint of moldability. In the present invention, the glass transition temperature of the amorphous resin is determined by increasing the temperature of the amorphous resin from 30 ° C. to the predicted glass transition temperature or higher in the differential calorimetry at 20 ° C./min. The glass transition temperature (Tg) observed when the temperature is measured again under the temperature rising condition at 20 ° C./min after holding for 1 minute, once cooling to 0 ° C. under the temperature lowering condition at 20 ° C./min, holding for 1 minute. Point to. Specific examples thereof include amorphous nylon resin, polycarbonate (PC) resin, polyarylate resin, ABS resin, poly (meth) acrylate resin, poly (meth) acrylate copolymer, polysulfone resin, and polyethersulfone resin. At least one kind may be exemplified, and one kind or two or more kinds may be used in combination. Among these amorphous resins, polycarbonate (PC) resin having particularly high transparency, and among ABS resins, transparent ABS resin, polyarylate resin, poly (meth) acrylate resin, and poly (meth) acrylate copolymer, polyether A sulfone resin can be preferably used. When an amorphous resin is used as various resins, in addition to the improvement in fluidity at the time of melt processing described above, high transparency can be maintained when an amorphous resin having excellent transparency is used. The characteristics that can be expressed. Here, when it is desired to develop high transparency in the amorphous resin composition, it is preferable to use a cyclic PAS having a different m in the formula (A) as the cyclic PAS. In addition, when a single cyclic PAS, that is, a single m of the formula (A) is used as the cyclic PAS, such a cyclic PAS tends to have a high melting point. When kneading, the cyclic PAS having a different m in the formula (A) has a melting temperature, although it does not sufficiently melt and disperse in the kneading and tends to become aggregates in the resin or to decrease transparency. This tends to be low, which is effective in improving the uniformity during melt-kneading. Here, the cyclic PAS obtained by the production method of the present invention is characterized in that m in the formula (A) is not single, and the formula (A) having m different from m = 2 to 50 is easily obtained. Therefore, it is particularly advantageous when it is desired to obtain an amorphous resin composition having high transparency.

  The resin composition obtained by blending cyclic PAS with various resins obtained above can be molded by any known method such as injection molding, extrusion molding, blow molding, press molding, spinning, etc. Can be processed and used. As molded products, they can be used as injection molded products, extrusion molded products, blow molded products, films, sheets, fibers, and the like. The various molded articles thus obtained can be used for various applications such as automobile parts, electrical / electronic parts, building members, various containers, daily necessities, household goods and sanitary goods. Moreover, the said resin composition and a molded article consisting thereof can be recycled. For example, a resin composition obtained by pulverizing a resin composition and a molded product comprising the resin composition, preferably in a powder form, and then adding additives as necessary, can be used in the same manner as the resin composition described above. It can also be a molded product.

(12) Conversion of cyclic PAS to a high degree of polymerization The cyclic PAS produced according to the present invention has excellent characteristics as described in (8), so that it can be suitably used as a prepolymer for obtaining a polymer. Is possible. Here, as the prepolymer, the cyclic PAS obtained by the cyclic PAS production method of the present invention may be used alone or may contain a predetermined amount of other components, but if it contains components other than the cyclic PAS, A PAS component such as a linear PAS or a PAS having a branched structure is particularly preferable. A polyarylene sulfide prepolymer that contains at least the cyclic PAS of the present invention and can be converted into a high polymerization degree by the method exemplified below is sometimes referred to as a PAS prepolymer.

  The conversion reaction of the cyclic PAS to a high degree of polymerization may be performed under conditions where a component having a higher molecular weight than the molecular weight of the cyclic PAS is generated from the cyclic PAS, for example, the cyclic PAS production method of the present invention. A method of heating a PAS prepolymer containing PAS and converting it to a high degree of polymerization can be exemplified as a preferable method. The heating temperature is preferably a temperature at which the PAS prepolymer melts, and there is no particular limitation as long as it is such a temperature condition. If the heating temperature is lower than the melt solution temperature of the PAS prepolymer, a long time tends to be required to obtain a PAS having a high molecular weight. Although the temperature at which the PAS prepolymer melts varies depending on the composition and molecular weight of the PAS prepolymer and the environment during heating, it cannot be uniquely indicated. For example, the PAS prepolymer is a differential scanning calorimeter. It is possible to grasp the melting solution temperature by analyzing with. If the heating temperature is too high, undesirable side reactions such as cross-linking reactions and decomposition reactions between PAS prepolymers, between PASs produced by heating, and between PAS and polyarylene sulfide prepolymers tend to occur. Therefore, it is desirable to avoid a temperature at which such an undesirable side reaction is prominent because the properties of the obtained PAS may deteriorate. Examples of the heating temperature at which the manifestation of such undesirable side reactions can be suppressed include 180 to 400 ° C, preferably 200 to 380 ° C, and more preferably 250 to 360 ° C. On the other hand, if there is no problem even if a certain degree of side reaction occurs, a temperature range of 250 to 450 ° C., preferably 280 to 420 ° C., can be selected. There is an advantage that can be performed.

  The heating time cannot be uniformly defined because it varies depending on various properties such as cyclic PAS content, m number, and molecular weight in the PAS prepolymer to be used, and conditions such as the heating temperature. It is preferable to set so that undesirable side reactions do not occur as much as possible. Examples of the heating time include 0.05 to 100 hours, preferably 0.1 to 20 hours, and more preferably 0.1 to 10 hours. If the time is less than 0.05 hours, the conversion of the PAS prepolymer to PAS tends to be insufficient, and if the time exceeds 100 hours, the possibility of adverse effects on the properties of the resulting PAS due to undesirable side reactions tends to become obvious. Not only that, but there may be economic disadvantages.

  In addition, various catalyst components that promote the conversion can be used for the PAS prepolymer upon conversion to a high degree of polymerization by heating. Examples of such catalyst components include ionic compounds and compounds having radical generating ability. Examples of the ionic compound include sulfur alkali metal salts such as thiophenol sodium salt and lithium salt, and examples of the compound capable of generating radicals include compounds capable of generating sulfur radicals upon heating. Specific examples include compounds containing a disulfide bond. When various catalyst components are used, the catalyst component is usually taken into PAS, and the obtained PAS often contains the catalyst component. In particular, when an ionic compound containing an alkali metal and / or other metal component is used as a catalyst component, most of the metal component contained therein tends to remain in the obtained PAS. In addition, PAS obtained using various catalyst components tends to increase in weight loss when PAS is heated. Therefore, when a higher purity PAS is desired and / or when a PAS with less weight loss when heated is desired, it is preferable to use as little catalyst components as possible and more preferably not to use them. Therefore, when converting the PAS prepolymer to a high degree of polymerization using various catalyst components, the amount of alkali metal in the reaction system containing the PAS prepolymer and the catalyst component is 100 ppm or less, preferably 50 ppm or less, more preferably Is 30 ppm or less, more preferably 10 ppm or less, and the disulfide weight based on the total sulfur weight in the reaction system is less than 1% by weight, preferably less than 0.5% by weight, more preferably less than 0.3% by weight, More preferably, the addition amount of the catalyst component is adjusted so as to be less than 0.1% by weight.

  Conversion of the PAS prepolymer to a high degree of polymerization by heating is usually performed in the absence of a solvent, but can also be performed in the presence of a solvent. The solvent is not particularly limited as long as it does not substantially cause undesirable side reactions such as inhibition of conversion to a high degree of polymerization by heating of the PAS prepolymer and decomposition or crosslinking of the produced PAS. Nitrogen-containing polar solvents such as methyl-2-pyrrolidone, dimethylformamide, dimethylacetamide, sulfoxide / sulfone solvents such as dimethyl sulfoxide, dimethyl sulfone, ketone solvents such as acetone, methyl ethyl ketone, diethyl ketone, acetophenone, dimethyl ether, dipropyl ether , Ether solvents such as tetrahydrofuran, halogen solvents such as chloroform, methylene chloride, trichloroethylene, ethylene chloride, dichloroethane, tetrachloroethane, chlorobenzene, methanol, ethanol, propylene Lumpur, butanol, pentanol, ethylene glycol, propylene glycol, phenol, cresol, alcohol phenol based solvents such as polyethylene glycol, benzene, toluene, and aromatic hydrocarbon solvents such as xylene. It is also possible to use an inorganic compound such as carbon dioxide, nitrogen, or water as a solvent in a supercritical fluid state. These solvents can be used as one kind or a mixture of two or more kinds.

  The conversion of the PAS prepolymer to a high degree of polymerization by heating may be performed in a mold for producing a molded product, as well as by a method using a normal polymerization reaction apparatus, an extruder, Any apparatus equipped with a heating mechanism, such as a melt kneader, can be used without particular limitation, and known methods such as a batch method and a continuous method can be employed.

  The atmosphere during the conversion of the PAS prepolymer to a high degree of polymerization by heating is preferably a non-oxidizing atmosphere, and is also preferably performed under reduced pressure. Moreover, when it carries out under pressure reduction conditions, it is preferable to make it the pressure reduction conditions after making the atmosphere in a reaction system once non-oxidizing atmosphere. Thereby, it is in the tendency which can suppress generation | occurrence | production of undesirable side reactions, such as a crosslinking reaction and a decomposition reaction between PAS prepolymers, between PAS produced | generated by heating, and between PAS and a PAS prepolymer. The non-oxidizing atmosphere is an atmosphere in which the oxygen concentration in the gas phase in contact with the PAS component is 5% by volume or less, preferably 2% by volume or less, more preferably an oxygen-free atmosphere, that is, nitrogen, helium, argon or the like. This indicates an inert gas atmosphere, and among these, a nitrogen atmosphere is particularly preferred from the viewpoint of economy and ease of handling. The reduced pressure condition means that the reaction system is lower than atmospheric pressure, and the upper limit is preferably 50 kPa or less, more preferably 20 kPa or less, and even more preferably 10 kPa or less. An example of the lower limit is 0.1 kPa or more, and 0.2 kPa or more is more preferable. When the decompression condition exceeds the preferred upper limit, an undesirable side reaction such as a crosslinking reaction tends to occur easily. On the other hand, when the decompression condition is less than the preferred lower limit, cyclic PAS having a low molecular weight contained in the PAS prepolymer is volatilized depending on the reaction temperature. It tends to be easier.

  The conversion of the PAS prepolymer to a high degree of polymerization can also be performed in the presence of a fibrous substance. Here, the fibrous substance is a thin thread-like substance, and an arbitrary substance having a structure elongated like a natural fiber is preferable. By converting the PAS prepolymer to a high polymerization degree in the presence of the fibrous substance, a composite material structure composed of PAS and the fibrous substance can be easily prepared. Since such a structure is reinforced by a fibrous material, it tends to have superior mechanical properties, for example, compared to the case of PAS alone.

  Here, among the various fibrous materials, it is preferable to use reinforcing fibers made of long fibers, which makes it possible to highly reinforce PAS. In general, when creating a composite material structure composed of a resin and a fibrous substance, the resin and the fibrous substance tend to become poorer due to the high viscosity when the resin is melted. In many cases, composite materials cannot be produced or expected mechanical properties do not appear. Here, wetting is the physical state of the fluid material and the solid substrate so that substantially no air or other gas is trapped between the fluid material such as a molten resin and the solid substrate such as a fibrous compound. Means there is good and maintained contact. Here, the lower the viscosity of the fluid substance, the better the wetting with the fibrous substance. Since the viscosity of the PAS prepolymer of the present invention when melted is significantly lower than that of a general thermoplastic resin such as PAS, the wettability with the fibrous material tends to be good. After the PAS prepolymer and the fibrous material form good wetting, the PAS prepolymer is converted into a high degree of polymerization according to the PAS production method of the present invention, so that the fibrous material and the high degree of polymerization (polyarylene) It is possible to easily obtain the composite material structure in which the sulfide is formed with good wetting.

As described above, it is preferable that the fibrous material is a reinforcing fiber composed of long fibers, and the reinforcing fiber used in the present invention is not particularly limited. However, as the reinforcing fiber suitably used, generally, a high-performance reinforcing fiber is used. And fibers having good heat resistance and tensile strength. For example, the reinforcing fiber includes glass fiber, carbon fiber, graphite fiber, aramid fiber, silicon carbide fiber, alumina fiber, and boron fiber. Among these, carbon fiber and graphite fiber, which have good specific strength and specific elastic modulus and have a great contribution to weight reduction, can be exemplified as the best. Any type of carbon fiber or graphite fiber can be used as the carbon fiber or graphite fiber depending on the application, but high strength and high elongation carbon having a tensile strength of 450 kgf / mm ² and a tensile elongation of 1.6% or more. Fiber is most suitable. In the case of using long fiber-like reinforcing fibers, the length is preferably 5 cm or more. In the range of this length, it becomes easy to sufficiently develop the strength of the reinforcing fiber as a composite material. Carbon fibers and graphite fibers may be used in combination with other reinforcing fibers. Moreover, the shape and arrangement | sequence of a reinforced fiber are not limited, For example, it can be used even if it is a single direction, a random direction, a sheet form, a mat form, a textile form, and a braid form. In particular, for applications that require high specific strength and specific elastic modulus, an array in which reinforcing fibers are aligned in a single direction is most suitable. Arrangements are also suitable for the present invention.

  The conversion of the PAS prepolymer to a high degree of polymerization can also be performed in the presence of a filler. Examples of the filler include non-fibrous glass, non-fibrous carbon, and inorganic fillers such as calcium carbonate, titanium oxide, and alumina.

  The present invention will be specifically described below with reference to examples. These examples are illustrative and not limiting.

<Filtration speed measurement method>
The filtration rate during the solid-liquid separation of the PAS mixture was measured by pressure filtration using a membrane filter. The measurement conditions are shown below.
Equipment: TSU-90A made by ADVANTEC
Filter medium: ADVANTEC T100A090C (PTFE pore size: 1.0 mm Size: 90 mm)

<Calculation method of required power for stirring>
The calculation formula of Nagata et al. Was used as a calculation method of the required stirring power given to the slurry in the tank. The following formulas are typical formulas.
-Power requirement for stirring The following formula was used as a method for calculating the power required for stirring applied to the slurry.

  Each symbol is represented by the following formula.

Re = stirring Reynolds number ρ × n × d / μ [−]
Z = depth of liquid [m]
D = tank diameter [m]
b = Wing width [m]
d = Blade diameter [m]
Np = power number [-]
μ = viscosity [Pa · s].

Furthermore, the power required for stirring was calculated by applying the above power number to the following formula.
P = Np × ρ × (d ^ 5) × (n ^ 3) / gc
P: Power required for stirring [kgf · m / sec]
Np: Number of powers [-]
ρ: Density [kg / m3]
d: Blade diameter [m]
n: number of revolutions [/ sec]
gc: Gravity conversion coefficient [kg · m / (kgf · s ^ 2)]

[Kgf · m / sec] × 9.8 = [W], [W] × 0.001 = [kW], and from here, the final slurry volume [m ³ ] and stirring time [hr] The unit [kWh / m ³ ] was calculated.

[Reference Example 1]
SUS316L 4-sheet paddle type, equipped with a stirrer having a blade width of 40 mm, a blade diameter of 400 mm, and a blade angle of 45 °, and a reaction of about 500 L having three baffle plates with a height of 720 mm and a width of 80 mm The inside of the tank of the kettle was replaced with nitrogen gas, a heating medium was passed through a jacket having a volume of about 100 L, and the system was kept at 250 ° C.

  Thereto was charged 400 kg of a mixture of 48 kg aqueous solution of sodium hydroxide, 14 kg of 48 wt. The reaction was carried out at 250 ° C. for 2 hours.

  The internal pressure of the reaction kettle was 0.5 MPa, and was in a pressurized state with respect to atmospheric pressure. Next, the reaction solution was transferred to another reaction vessel having the same stirrer, baffle plate, volume, and internal pressure of 0.2 MPa, and N-methyl-2-pyrrolidone was stirred at 164 rpm at about 80 kg / hr. The concentration operation was carried out by scattering. The concentrated mixture was then allowed to cool to about 110 ° C.

[Reference Example 2]
A membrane filter was set in the pressure filter described above, and the entire filter was kept at 110 ° C. using a ribbon heater. Thereafter, about 100 g of the concentrated mixed solution was heated to 110 ° C. with an oil bath or the like, put into a pressure filter, and immediately after that, the inside of the apparatus was pressurized to 0.4 MPa using nitrogen. In this state, the bottom plug valve of the apparatus was opened, and the filtrate was measured every time.

[Example 1]
150 kg of the reaction solution obtained in Reference Example 1 is a three-paddle type made of SUS316L, equipped with a stirrer having a blade width of 40 mm, a blade diameter of 230 mm, and a blade angle of 45 °, a height of 450 mm, and a width of 70 mm. The liquid was transferred to an approximately 300 L reaction kettle having two rectangular parallelepiped baffle plates, and the pump was placed on standby for about 2 hours. At that time, circulation was performed using a rotary pump, and the rotational speed of the rotating body of the pump was 480 rpm. The required power for stirring was calculated to be 0.38 kWh / m ³ by the calculation method described above. The concentrated mixture at this time was collected and allowed to cool to about 20 ° C.

Thereafter, 100 g of this concentrated mixture was heated in an oil bath so that the liquid temperature became 110 ° C. During heating, the glass rod was slowly stirred so that the temperature distribution in the system was uniform, and care was taken not to apply a stirring load. It is assumed that there is no power required for stirring at this time. Thereafter, the reaction solution was charged into a pressure filter that had been heated and held at 110 ° C. using a ribbon heater, and 0.4 MPa under a nitrogen atmosphere using a membrane filter (PTFE) having a pore diameter of 1 mm. The solid-liquid separation was performed under the pressure of The filtration rate at that time was 210.3 kg / hr · m ² .

[Comparative Example 1]
150 kg of the reaction solution obtained in Reference Example 1 is a three-paddle type made of SUS316L, equipped with a stirrer having a blade width of 40 mm, a blade diameter of 230 mm, and a blade angle of 45 °, a height of 450 mm, and a width of 70 mm. The liquid was transferred to an approximately 300 L reaction kettle having two rectangular parallelepiped baffle plates, and the pump was placed on standby for about 2 hours. At that time, circulation was performed using a canned motor pump, and the rotation speed of the impeller included in the pump was 3400 rpm. The power required for stirring by this was 114 kWh / m ^{3 when} calculated by the calculation method described above. The concentrated mixture at this time was collected and allowed to cool to about 20 ° C.

Thereafter, 100 g of this concentrated mixture was heated in an oil bath so that the liquid temperature became 110 ° C. During heating, the glass rod was slowly stirred so that the temperature distribution in the system was uniform, and care was taken not to apply a stirring load. It is assumed that there is no power required for stirring at this time. Thereafter, the reaction solution was charged into a pressure filter that had been heated and held at 110 ° C. using a ribbon heater, and 0.4 MPa under a nitrogen atmosphere using a membrane filter (PTFE) having a pore diameter of 1 mm. The solid-liquid separation was performed under the pressure of The filtration rate at that time was 80.58 kg / hr · m ² .

[Example 2]
A mixture of 37 kg cyclic PAS, 11 kg linear PAS, 414 kg NMP, 138 kg H ₂ O was heated to 80 ° C. Thereafter, the mixture was put into a kettle equipped with a stirrer having a four-paddle type made of SUS304 and having a blade width of 90 mm, a blade diameter of 800 mm, and a blade angle of 45 °, and the mixture was agitated for about 1 hour at 100 rpm. The required power for stirring was 0.41 kWh / m ^{3 when} calculated by the calculation method described above.

Thereafter, this mixture was cooled to about 20 ° C. and allowed to stand for 12 hours, and then about 100 g was recovered and heated in an oil bath so that the liquid temperature became 110 ° C. During heating, the glass rod was slowly stirred so that the temperature distribution in the system was uniform, and care was taken not to apply a stirring load. It is assumed that there is no power required for stirring at this time. Thereafter, the reaction solution was charged into a pressure filter that had been heated and held at 110 ° C. using a ribbon heater, and 0.4 MPa under a nitrogen atmosphere using a membrane filter (PTFE) having a pore diameter of 1 mm. The solid-liquid separation was performed under the pressure of The filtration rate at that time was 260.33 kg / hr · m ² .

[Comparative Example 2]
A mixture of 37 kg cyclic PAS, 11 kg linear PAS, 414 kg NMP, 138 kg H ₂ O was heated to 80 ° C. Thereafter, the mixture was put into a kettle equipped with a stirrer having a four-paddle type made of SUS304 and having a blade width of 90 mm, a blade diameter of 800 mm, and a blade angle of 45 °, and the mixture was stirred for about 16 hours at 100 rpm. The power required for stirring at this time was 6.67 kWh / m ³ .

Thereafter, this mixture was cooled to about 20 ° C. and allowed to stand for 12 hours, and then about 100 g was recovered and heated in an oil bath so that the liquid temperature became 110 ° C. During heating, the glass rod was slowly stirred so that the temperature distribution in the system was uniform, and care was taken not to apply a stirring load. It is assumed that there is no power required for stirring at this time. Thereafter, the reaction solution was charged into a pressure filter that had been heated and held at 110 ° C. using a ribbon heater, and 0.4 MPa under a nitrogen atmosphere using a membrane filter (PTFE) having a pore diameter of 1 mm. The solid-liquid separation was performed under the pressure of The filtration rate at that time was 86.04 kg / hr · m ² .

Claims (8)

A method for recovering (c) by solid-liquid separation from an organic polar solvent (c) containing at least cyclic polyarylene sulfide (a) and linear polyarylene sulfide (b), wherein A method for recovering cyclic polyarylene sulfide (a), wherein the liquid is transferred to a solid-liquid separator so that the required power for stirring applied to the mixture is 2.0 kWh / m ³ or less in a temperature range below the boiling point. . The ring according to claim 1, wherein the cyclic polyarylene sulfide (a) is a compound represented by the following formula (1), wherein Ar is an arylene group, and a value of m is 2 to 50. Process for recovering the formula polyarylene sulfide (a).

The method for recovering cyclic polyarylene sulfide (a) according to claim 1 or 2, wherein the organic polar solvent (c) is an organic amide solvent. The method for recovering a cyclic polyarylene sulfide (a) according to any one of claims 1 to 3, wherein the organic polar solvent (c) is an aprotic solvent. (C) used as a solvent may be mixed with (d), which is a second solvent, and (d) is a protic solvent. A method for recovering the cyclic polyarylene sulfide. The method for recovering the cyclic polyarylene sulfide (a) according to any one of claims 1 to 5, wherein solid-liquid separation is performed using a filter medium having an air permeability of less than 5.0 cm ³ / cm ² · sec. The method for recovering a cyclic polyarylene sulfide (a) according to any one of claims 1 to 6, wherein solid-liquid separation is performed in a temperature range of 10 ° C or higher and 200 ° C or lower, The method for recovering cyclic polyarylene sulfide according to any one of claims 1 to 7, wherein the solid-liquid separation is performed in an inert gas atmosphere.