JP2009227952A - Method for producing cyclic polyarylene sulfide - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for efficiently producing an industrially useful cyclic polyarylene sulfide by an economical and simple process in a short time. <P>SOLUTION: The method for producing a cyclic polyarylene sulfide comprises heating and reacting a reaction mixture which is composed of at least (a) a linear polyarylene sulfide, (b) a sulfidizing agent, (c) a dihalogenated aromatic compound and (d) an organic polar solvent, wherein ≥1.25 liters of the organic polar solvent is used per 1 mole of the sulfur content in the reaction mixture. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for producing a cyclic polyarylene sulfide. More specifically, the present invention relates to a method for efficiently producing a cyclic oligoarylene sulfide in a short time by an economical and simple method.

  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.

  As a method for producing a cyclic polyarylene sulfide, for example, a method in which a diaryl disulfide compound is oxidatively polymerized under ultradilution conditions has been proposed (see, for example, Patent Document 1). In this method, it is presumed that cyclic polyarylene sulfide is produced with high selectivity, and that only a small amount of linear polyarylene sulfide is produced, and it is considered that cyclic polyarylene sulfide is obtained in high yield. However, in this method, it is essential to carry out the reaction under ultra-dilution conditions, and the amount of cyclic polyarylene sulfide obtained per unit volume of the reaction vessel is very small, and cyclic polyarylene sulfide can be obtained efficiently. From this point of view, it was a method with many problems. Further, this method is a method using oxidative polymerization, and since this method requires mild conditions around room temperature, the reaction requires a long time of several tens of hours and is inferior in productivity. Furthermore, the polyarylene sulfide by-produced by this method has a low molecular weight including a disulfide bond derived from the starting diaryl disulfide and has a molecular weight close to that of the target cyclic polyarylene sulfide. It was difficult to separate the by-product polyarylene sulfide, and it was extremely difficult to efficiently obtain a high-purity cyclic polyarylene sulfide. In addition, this method requires an equivalent amount of an expensive oxidizing agent such as dichlorodicyanobenzoquinone as the starting diaryl disulfide for the progress of the oxidative polymerization, and it has not been possible to obtain a cyclic polyarylene sulfide at a low cost. A method of utilizing oxygen as an oxidant in the presence of a metal catalyst in oxidative polymerization has also been proposed. In this method, the oxidant is inexpensive, but the reaction is difficult to control and a large amount of by-product oligomers are produced. On the other hand, there are many problems such as the necessity of an extremely long time for the reaction, and in any case, it was not possible to efficiently obtain a cyclic polyarylene sulfide having a high purity at low cost.

  As another method for producing cyclic polyarylene sulfide, a method in which a copper salt of 4-bromothiophenol is heated under ultra-diluted conditions in quinoline is disclosed. In this method as well, the ultra-dilution conditions are indispensable as in the case of Patent Document 1, and a long time is required for the reaction, and the method is extremely low in productivity. Furthermore, in this method, it is difficult to separate the by-produced copper bromide from the product cyclic polyarylene sulfide, and the resulting cyclic polyarylene sulfide has low purity (see, for example, Patent Document 2). .)

  As a method for obtaining a cyclic polyarylene sulfide in a high yield, a dihaloaromatic compound such as 1,4-bis- (4′-bromophenylthio) benzene and sodium sulfide are brought to reflux temperature in N-methylpyrrolidone. A method of contacting is disclosed (for example, Non-Patent Document 1). In this method, it can be assumed that the amount of the organic polar solvent relative to 1 mol of the sulfur component in the reaction mixture is 1.25 liters or more, so that it is possible to obtain cyclic polyarylene sulfide. It is necessary to use a large amount of a dihaloaromatic compound, and since the dihaloaromatic compound used is a very special compound, it is a method that lacks industrial feasibility and has been desired to be improved.

  As a method for producing cyclic polyarylene sulfide from a general-purpose raw material, p-dichlorobenzene as a dihalogenated aromatic compound and sodium sulfide as an alkali metal sulfide are reacted in N-methylpyrrolidone which is an organic polar solvent, Next, a method is disclosed in which polyphenylene sulfide obtained by removing the solvent under heating under reduced pressure and then washing with water is recovered from the saturated solution portion of the extract obtained by extraction with methylene chloride (for example, patents). Reference 3). This method has a problem that most of the product is high molecular weight polyphenylene sulfide, and only a very small amount of cyclic polyarylene sulfide (less than 1% yield) can be obtained.

  Further, as a method for obtaining polyarylene sulfide, a method is disclosed in which an aromatic compound or thiophene containing at least one nucleus-substituted halogen is reacted with an alkali metal monosulfide at an elevated temperature in a polar organic solvent. (For example, refer to Patent Document 4, Patent Document 5, and Patent Document 6). Unlike the object of the present invention, these methods aim to obtain polyarylene sulfide, and nothing is disclosed about the production of cyclic polyarylene sulfide. In addition, since these methods aim to obtain polyarylene sulfide having a high molecular weight, the amount of the organic polar solvent used for the sulfidizing agent is reduced, and the organic polar solvent is used per mole of sulfur atom of the sulfidizing agent. There is no disclosure of a reaction using 1.25 liters or more, and a useful product is obtained when the organic polar solvent is used in excess of 1 liter per mole of sulfur atom of the sulfiding agent. It is clearly not possible. Furthermore, nothing is mentioned about the use of linear polyarylene sulfide, which is a feature of the present invention, as a raw material.

  As a method for obtaining an arylene sulfide-based polymer using linear polyarylene sulfide as a raw material, an alkali thiolate group is present at at least one terminal obtained by depolymerizing polyarylene sulfide with an alkali metal sulfide. A method of polymerizing a prepolymer and a dihalogenated aromatic compound is disclosed (for example, see Patent Document 7). This method relates to the modification of polyarylene sulfide, which not only has a different purpose from the present invention, but has no description regarding the production of cyclic polyarylene sulfide. In addition, since this method aims to obtain a polyarylene sulfide having a high molecular weight, it only discloses a reaction in which the amount of the organic polar solvent per mole of the sulfur component in the reaction mixture is about 1 kg or less, There is no description of a reaction using 1.25 liters or more of an organic polar solvent per mole of sulfur component in the reaction mixture necessary for carrying out the present invention. Further, in this method, first, a polyarylene sulfide and an alkali metal sulfide are allowed to act to obtain a prepolymer having an alkali thiolate group at at least one end, and then the prepolymer and the dihalogenated aromatic compound are polymerized. It is essential to go through a step reaction, and the reaction must be strictly controlled compared to the method of reacting linear polyarylene sulfide, sulfidizing agent and dihalogenated aromatic compound at the same time as in the present invention. In addition, there are many problems to be solved such as complicated operation.

As another method of reacting with an alkali metal sulfide using polyarylene sulfide as a raw material, a method of producing a highly reactive polyphenylene sulfide by introducing a thiolate group at the terminal of the polyphenylene sulfide (see, for example, Patent Document 8), poly A method for producing a polyarylene sulfide copolymer by reacting an alkali metal sulfide with an arylene sulfide to synthesize a prepolymer having an alkali thiolate group at at least one end and then reacting with various dihalogenated aromatic compounds (for example, patents) References 9 to 12) are disclosed, but in any case, the object is different from the present invention, and the cyclic polyarylene sulfide that is the object of the present invention is not mentioned at all. Sulfur formation in the reaction mixture necessary to carry out No mention about the organic polar solvent per 1 mole of using more than 1.25 liters reaction.
Japanese Patent No. 3200027 (Claims) US Pat. No. 5,869,599 (page 14) JP 05-163349 A (page 7) Japanese Examined Patent Publication No. 45-3368 (Pages 6-8) Japanese Examined Patent Publication No. 52-12240 (pages 10-20) Japanese Examined Patent Publication No. 63-3375 (pages 6 to 9) JP 04-7334 A (Claims) Japanese Patent Laid-Open No. 02-140233 (Claims) Japanese Patent Laid-Open No. 04-213329 (Claims) Japanese Patent Laid-Open No. 04-311725 (Claims) JP 05-043689 A (Claims) JP 05-98007 A (Claims) Bull.Acad.Sci., Vol.39, p.763-766, 1990

  An object of the present invention is to solve the above-mentioned problems of the prior art and to provide a method for efficiently producing a cyclic polyarylene sulfide in a short time by an economical and simple method.

In response to the above problems, the present invention
1. At least (a) linear polyarylene sulfide,
(B) a sulfidizing agent,
(C) a dihalogenated aromatic compound, and (d) an organic polar solvent,
Is a method of producing a cyclic polyarylene sulfide by heating and reacting a reaction mixture containing 1.25 liters or more of an organic polar solvent with respect to 1 mol of a sulfur component in the reaction mixture. A method for producing a cyclic polyarylene sulfide,
2. The method for producing a cyclic polyarylene sulfide according to item 1, wherein the heating temperature is a temperature exceeding the reflux temperature at normal pressure of the reaction mixture,
3. Item 3. The method for producing a cyclic polyarylene sulfide according to Item 1 or 2, wherein the amount of the organic solvent used is 50 liters or less with respect to 1 mole of the sulfur component in the reaction mixture.
4). The method for producing a cyclic polyarylene sulfide according to any one of items 1 to 3, wherein the pressure when heating the reaction mixture is 0.05 MPa or more in terms of gauge pressure,
5. The method for producing a cyclic polyarylene sulfide according to any one of Items 1 to 4, wherein the dihalogenated aromatic compound (c) is dichlorobenzene,
6). 6. The method for producing a cyclic polyarylene sulfide according to any one of items 1 to 5, wherein the sulfidizing agent (b) is an alkali metal sulfide,
7). Items 1 to 6, characterized in that polyarylene sulfide obtained by bringing a sulfidizing agent and a dihalogenated aromatic compound into contact with each other in an organic polar solvent is used as linear polyarylene sulfide (a). A method for producing the cyclic polyarylene sulfide according to any one of
8). A cyclic polyarylene sulfide obtained by heating and reacting a sulfidizing agent and a dihalogenated aromatic compound with an organic polar solvent of 1.25 liters or more per mole of the sulfur component of the sulfidizing agent; Item 1. The linear polyarylene sulfide obtained by separating cyclic polyarylene sulfide from a polyarylene sulfide mixture containing linear polyarylene sulfide is used as the linear polyarylene sulfide (a). The method for producing cyclic polyarylene sulfide according to any one of items 6 to 6;
9. At least a reaction mixture composed of linear polyarylene sulfide, a sulfidizing agent, a dihalogenated aromatic compound, and an organic polar solvent is heated using 1.25 liters or more of an organic polar solvent with respect to 1 mol of a sulfur component in the reaction mixture. The linear polyarylene sulfide obtained by separating the cyclic polyarylene sulfide from the polyarylene sulfide mixture containing the cyclic polyarylene sulfide and the linear polyarylene sulfide obtained by the reaction is converted into a linear polyarylene. Item 7. The method for producing cyclic polyarylene sulfide according to any one of Items 1 to 6, wherein the method is used as sulfide (a).
10. The method for producing a cyclic polyarylene sulfide according to any one of Items 1 to 9, wherein the linear polyarylene sulfide (a) has a weight average molecular weight of 2,500 or more.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of cyclic polyarylene sulfide can be provided, More specifically, the method of manufacturing cyclic oligo arylene sulfide efficiently in a short time by an economical and simple method can be provided.

Embodiments of the present invention will be described below.

(1) Sulfiding agent The sulfidizing agent used in the present invention may be any one that can introduce a sulfide bond into a dihalogenated aromatic compound, or that can act on an arylene sulfide bond to produce an arylene thiolate. Examples include alkali metal sulfides, alkali metal hydrosulfides, and hydrogen sulfide.

  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 preferred 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 determined from the actual charge amount when a partial loss of the sulfidizing agent occurs before the start of the reaction between the linear polyarylene sulfide and the dihalogenated aromatic compound due to dehydration operation or the like. It shall mean the remaining amount after deducting the loss.

  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 sulfiding agent, it is particularly preferable to use an alkali metal hydroxide at the same time, but the amount used is 0.95 to 1. A range of 50 moles, preferably 1.00 to 1.25 moles, more preferably 1.005 to 1.200 moles can be exemplified. 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.

(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 0.9 to 2.0 mol, more preferably in the range of 0.95 to 1.5 mol, per mol of the sulfur component of the sulfiding agent. The range of .98 to 1.2 mol is more preferable.

(3) Linear polyarylene sulfide The linear PAS in the present invention is a linear PAS having a repeating unit of the formula, — (Ar—S) —, preferably containing 80 mol% or more of the repeating unit. A homopolymer or a linear copolymer. Ar includes units represented by the following formulas (A) to (L), among which the formula (A) is particularly preferable.

(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.)

  As long as this repeating unit is a main structural unit, it can contain a small amount of branching units or crosslinking units represented by the following formulas (M) to (P). The amount of copolymerization of these branched units or cross-linked units is preferably in the range of 0 to 1 mol% with respect to 1 mol of-(Ar-S)-units.

  Further, 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 PASs include p-phenylene sulfide units as the main structural unit of the polymer.

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

  The melt viscosity of various linear PASs in the present invention is not particularly limited, but the melt viscosity of 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 easy availability. Further, the molecular weight of the linear PAS is not particularly limited, and general PAS can be used. Examples of the weight average molecular weight of such a PAS include 1,000 to 1,000,000, 500-500,000 are preferable and 5,000-100,000 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. For example, at least one nucleus-substituted halogen represented by Patent Documents 3 to 5 described above can be used. A method of reacting an aromatic compound or thiophene with an alkali metal monosulfide at an elevated temperature in a polar organic solvent, preferably contacting the sulfiding agent with a dihalogenated aromatic compound in an organic polar solvent Can be obtained by: 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 produced 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. It was obtained by separating cyclic polyarylene sulfide from a polyarylene sulfide mixture containing cyclic polyarylene sulfide and linear polyarylene sulfide obtained by heating and reacting using the above organic polar solvent. The method using linear polyarylene sulfide is a particularly preferable method. Further, a linear polyarylene sulfide produced by the practice of the present invention, that is, a reaction mixture composed of at least a linear polyarylene sulfide, a sulfidizing agent, a dihalogenated aromatic compound, and an organic polar solvent is converted into a sulfur component in the reaction mixture. From a polyarylene sulfide mixture containing a cyclic polyarylene sulfide and a linear polyarylene sulfide obtained by heating and reacting with 1.25 liters or more of an organic polar solvent per mole, a cyclic polyarylene sulfide is obtained. The use of linear polyarylene sulfide obtained by separation is a particularly preferable method. 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 by-product 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.

  The amount of linear PAS used is not limited as long as linear PAS is contained in the reaction mixture at the start of the reaction, that is, when the conversion rate of the dihalogenated aromatic compound charged in the reaction system is zero. Is preferably in the range of 0.1 to 20 repeating unit moles per mole of sulfur component of the sulfiding agent, based on the repeating unit of the formula — (Ar—S) — which is the main structural unit of A range of 15 repeating unit moles is more preferred, and a range of 1 to 10 repeating unit moles is even more preferred. When the amount of linear PAS used is in a preferred range, cyclic PAS tends to be obtained in high yield, and the reaction tends to proceed in a shorter time.

  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 as the powder form of a dry state, a granular form, a granular form, and a pellet form, 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 linear PAS in the form of a resin composition containing inorganic fillers can also be used.

(4) Organic Polar Solvent 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, caprolactam such as N-methyl-ε-caprolactam and ε-caprolactam. Aprotic organic solvents such as 1,3-dimethyl-2-imidazolidinone, N, N-dimethylacetamide, N, N-dimethylformamide, hexamethylphosphoric triamide, and mixtures thereof. Is preferably used because of its high stability. Among 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 the reaction solvent in the production of cyclic PAS is 1.25 liters or more, preferably 1.5 liters or more, more preferably, with respect to 1 mole of the sulfur component contained in the reaction mixture. 2 liters or more. In addition, the sulfur component which a reaction mixture contains here is the sum total of the sulfur component contained in the sulfur component contained in the linear polyarylene sulfide used for a raw material, and the sulfidizing agent used for a raw material. Here, the “number of moles” of the sulfur component contained in the linear polyarylene sulfide is the “number of repeating units” of the polymer containing one sulfur atom. For example, one molecule of linear polyphenylene sulfide having a degree of polymerization of 100 is calculated as 100 mol, not 1 mol. As long as the essence of the present invention is not impaired, a compound containing a sulfur component in addition to the linear polyarylene sulfide and the sulfidizing agent can be additionally present in the reaction mixture. Sulfur components derived from sulfur-containing compounds that do not substantially act on the reaction of the present invention need not be taken into account. Further, the upper limit of the amount of the organic polar solvent is not particularly limited, but it is preferably 50 liters or less with respect to 1 mol of the sulfur component contained in the reaction mixture from the viewpoint of more efficiently producing cyclic PAS. More preferably, it is more preferably 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 the method of the present invention has extremely high reaction efficiency. The reaction of the raw material sulfidizing agent with linear PAS, the reaction of the sulfidizing agent with a dihalogenated aromatic compound, the sulfidizing agent and It is presumed that the reaction between the reaction intermediate produced by the reaction of linear PAS and the dihalogenated aromatic compound proceeds very rapidly, which favorably acts on the production of the cyclic compound. Here, the amount of the organic polar solvent used 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.

(5) Cyclic polyarylene sulfide The cyclic polyarylene sulfide in the present invention is a cyclic compound having a repeating unit of formula:-(Ar-S)-as a main constituent unit, and preferably 80 mol of the repeating unit. % Or more of the compound represented by the following general formula (Q).

  Here, examples of Ar can include units represented by the formulas (A) to (L), among which the formulas (A) to (C) are preferable, and the formulas (A) and (B) are more preferable. Formula (A) is particularly preferable.

  In addition, in cyclic polyarylene sulfide, repeating units, such as said Formula (A)-Formula (L), 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 polyarylene sulfides 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 (Q) formula of cyclic polyarylene sulfide, 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 into a high degree of polymerization, it is preferably heated at a temperature higher than the melting point of the cyclic polyarylene sulfide. Since the melting temperature of the cyclic polyarylene sulfide tends to be higher when the value of the polyarylene sulfide is increased, the conversion of the polyarylene sulfide prepolymer to a high degree of polymerization can be performed at a lower temperature. The above range is advantageous.

  Further, the cyclic polyarylene sulfide may be either a single compound having a single repeating number or a mixture of cyclic polyarylene sulfides having different repeating numbers. However, the cyclic polyarylene sulfide may be a mixture of cyclic polyarylene sulfides having different repeating numbers. The melt solution temperature tends to be lower than that of a single compound having a single number of repetitions, and the use of a mixture of cyclic polyarylene sulfides having different numbers of repetitions is used in the conversion to the above-mentioned high degree of polymerization. This is preferable because the temperature can be lowered.

(6) Method for Producing Cyclic Polyarylene Sulfide The present invention comprises at least (a) a linear polyarylene sulfide, (b) a sulfidizing agent, (c) a dihalogenated aromatic compound, and (d) an organic polar solvent. The reaction mixture is heated to react to produce the cyclic polyarylene sulfide.

  In the production of the cyclic PAS of the present invention, it is preferable to heat the reaction mixture composed of the above components beyond the reflux temperature of the reaction mixture under normal pressure. 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. Examples of the method for bringing the reaction mixture into a heated state exceeding the reflux temperature under normal pressure include a method of reacting the reaction mixture under a pressure exceeding normal pressure and a method of heating the reaction mixture in a sealed container.

  A more preferable reaction temperature in the production of the cyclic PAS of the present invention is a temperature at which the linear PAS used as a raw material melts in the reaction mixture. The raw material linear PAS is generally in a solid state near room temperature, and in the solid state, the formation reaction of the cyclic PAS which is the object of the present invention is difficult to proceed, but the temperature at which the linear PAS melts and dissolves. By carrying out the reaction, the reaction system becomes uniform, the reaction rate dramatically increases, and the time required for the reaction tends to be shortened. This temperature cannot be determined uniquely because it varies depending on the type and amount of the components in the reaction mixture, the structure of the linear PAS used as a raw material, the molecular weight, etc., but is usually 120 to 350 ° C., preferably 200 to 320. C., more preferably 230 to 300.degree. C., and still more preferably 240 to 280.degree. In this preferred temperature range, a higher reaction rate can be obtained, the reaction tends to be uniform and easy to proceed, and the generated cyclic PAS tends not to be decomposed. It tends to be. 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 structure and molecular weight of the linear PAS of the raw material used, the sulfidizing agent, the dihalogenated aromatic compound, the type of the organic polar solvent, the amount of these raw materials, or the reaction temperature. Although not possible, 0.1 hour or more is preferable, and 0.5 hour or more is more preferable. By setting it as this preferable time or more, since unreacted raw material components can be reduced sufficiently, cyclic PAS can be produced with good yield, and 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 characteristic that an extremely high reaction rate is easily obtained, and thus the reaction proceeds sufficiently even within 10 hours, preferably within 6 hours, more preferably 3 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 is not particularly limited, but a pressure that allows the reflux temperature of the reaction mixture to be exceeded under normal pressure is preferable. 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. Preferably it is 0.3 MPa or more, More preferably, 0.4 MPa or more can be illustrated. Moreover, as a preferable upper limit of pressure, 10 MPa or less, More preferably, 5 MPa or less can be illustrated. In such a preferable pressure range, the time required for the production of cyclic PAS tends to be shortened. In the case where the amount of the organic polar solvent used in the production of the cyclic PAS is increased, that is, in the condition where the concentration of the linear PAS, the sulfidizing agent and the dihalogenated aromatic compound as raw materials in the reaction mixture is low, the preferable pressure range. There is a tendency that the effect of carrying out the reaction is particularly great, and it is possible to further improve the raw material consumption rate and / or the selectivity of the target cyclic PAS. The reason for this is not clear at present, but in the production of cyclic PAS, some of the raw materials such as dihalogenated aromatic compounds that are volatile under the heating conditions in the reaction exist in the gas phase in the reaction system, and the liquid phase The reaction with the reaction substrate may be difficult to proceed, and volatilization in the reaction system of such raw materials can be suppressed by setting the preferred pressure range so that the reaction proceeds more efficiently. I guess it will be. Further, in order to set the pressure at the time of heating the reaction mixture to the above preferable pressure range, the reaction mixture is reacted with an inert gas described later at an optional stage such as before starting the reaction or during the reaction, preferably before starting the reaction. It is also a preferable method to pressurize the system. Here, the gauge pressure is a relative pressure based on the atmospheric pressure, and is equivalent to a pressure value obtained by subtracting the atmospheric pressure from the absolute pressure.

  In general, a cyclic compound is formed by forming a bond in a molecule of a linear compound having a relatively small number of repeating units as a precursor. Also in the cyclic PAS of the present invention, for example, it is considered that a cyclic PAS having a repeating unit number m is formed by an intramolecular reaction of a linear PAS having a repeating unit number m. In the present invention, the raw linear PAS is sulfided. It is presumed that by reacting with the agent, a linear compound having a relatively small number of repeating units that can be a precursor of the cyclic compound is generated, and the generation of the cyclic compound proceeds via this. Here, for example, when a linear PAS having a repeating unit number m and a linear PAS having a repeating unit number n react between molecules, a linear PAS having a repeating unit number (m + n) is generated. That is, in general, when producing a cyclic compound, not a few linear compounds due to intermolecular reactions are produced as a by-product, and it is important to preferentially proceed intramolecular reactions when producing cyclic compounds. In the case of PAS, it is generally known that linear PAS having a large number of repeating units tends to have poor solubility in an organic polar solvent, whereas the higher the temperature, the higher the solubility of the PAS component. Therefore, for the purpose of producing cyclic PAS, when it is desired to suppress the production of linear PAS, generally a low reaction temperature is adopted, and even in the production of known cyclic PAS, a reaction temperature exceeding the reflux temperature is not adopted. . On the other hand, in the case of producing a high molecular weight polymer of linear PAS, a high reaction temperature, which is a condition in which the PAS component is sufficiently dissolved in an organic polar solvent, is employed, and in the production of a known high molecular weight PAS. There is a strong tendency to employ a reaction temperature exceeding the reflux temperature, and it has been reported that PAS having a high molecular weight can be obtained in a high yield. As a result of intensive studies on the production method of cyclic PAS, the present inventors have surprisingly found that a high temperature range exceeding the reflux temperature of the reaction mixture, which is a temperature range in which a high molecular weight linear PAS is likely to be obtained, is the present invention. It has been found that the cyclic PAS can be obtained in good yield in a short time, and the present invention has been completed. Furthermore, in the temperature range preferably employed for the production of the cyclic PAS of the present invention, not only is the cyclic PAS obtained in good yield, but the by-product linear PAS is easily obtained as a high molecular weight product. Found to have. Here, the cyclic PAS and the linear PAS having a high molecular weight, for example, have significantly different solubility characteristics in a solvent, so that the cyclic PAS and the linear PAS can be easily separated. This is also the production of the cyclic PAS of the present invention. This is an excellent effect of the method. Therefore, according to the method for producing a cyclic PAS of the present invention, an extremely high-purity cyclic PAS can be easily obtained by additionally performing, for example, a cyclic PAS recovery operation described later. On the other hand, in the temperature range below the reflux temperature, which is a known production method of cyclic PAS, the raw linear PAS is difficult to melt and dissolve in the reaction mixture, and the reaction does not proceed easily. It seems that only low molecular weight can be obtained as a by-product linear PAS due to its low concentration, and it is difficult to obtain a high-purity cyclic PAS because it is difficult to separate cyclic PAS from linear PAS. It is in.

  In the method for producing cyclic PAS of the present invention, linear PAS, a sulfidizing agent, a dihalogenated aromatic compound, and an organic polar solvent are charged into a reactor, and the reaction is carried out as a reaction mixture containing these as essential components. The order in which these essential components are charged into the reactor is not particularly limited, but a method of first charging all or a part of the organic polar solvent to be used and then charging the other components is preferable for homogenizing the reaction mixture. 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, Performing on stirring conditions is preferable for homogenization of a reaction system. In addition, there is no restriction | limiting in particular in the temperature at the time of charging the said raw material here, For example, you may react after charging a raw material near room temperature, or you may supply a raw material to the reactor temperature-controlled beforehand to the temperature preferable for reaction mentioned above. It is also possible to carry out the reaction by charging. It is also possible to continuously carry out the reaction by sequentially charging the raw material into the reaction system in which the reaction is performed.

It is also possible to use a sulfidizing agent, a dihalogenated aromatic compound, linear PAS, and an organic polar solvent containing water. In general, in the reaction using a sulfidizing agent and a dihalogenated aromatic compound, the reaction rate tends to decrease as the amount of water in the reaction mixture increases. Since the reaction proceeds very quickly, it is possible to perform a sufficient reaction without strictly controlling the amount of water in the reaction mixture. Therefore, the amount of water in the reaction mixture of the present invention is not particularly limited, but at the time when the reaction starts, that is, when the conversion rate of the dihalogenated aromatic compound (hereinafter sometimes abbreviated as DHA) charged to the reaction system is zero. The water content can be exemplified as a preferable range of 0.2 mol or more and 20 mol or less per mol of sulfur component in the reaction mixture, preferably 0.5 mol or more and 10 mol or less, 0.6 mol or more and 8 mol or less. Is more preferable. When the sulfidizing agent, organic polar solvent, dihalogenated aromatic compound, linear PAS and other components that form the reaction mixture contain water, the reaction starts when the amount of water in the reaction mixture exceeds the above range. It is possible to reduce the amount of water in the reaction system before or during the reaction, and to keep the amount of water within the above range, which tends to yield a cyclic PAS efficiently in a short time. . In addition, when the water content of the reaction mixture is less than the above preferable range, it is also a preferable method to add water so that the above water content is obtained. The conversion rate of 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 (%) = [[DHA charge (mol) −DHA remaining amount (mol)] / [DHA charge ( Mol) -DHA excess (mole)]] × 100%
(B) In cases other than the above (a) Conversion (%) = [[DHA charge (mol) -DHA remaining amount (mol)] / [DHA charge (mol)]] × 100%

  Further, in the production of cyclic PAS, at an optional stage where the reaction is continued for a desired time and the amount of raw materials charged is reduced, any one or more of linear PAS, sulfidizing agent, dihalogenated aromatic compound and organic polar solvent is used. It is also possible to continue the reaction by adding. It is important to consider the amount of the sulfur component in the reaction mixture before addition, and the amount added here is an organic polar solvent with respect to 1 mol of the sulfur component in the reaction mixture after the addition of raw materials. It is strongly desired that the addition be performed within a range of 1.25 liters or more.

  As described above, the addition of the linear PAS, the sulfidizing agent and the dihalogenated aromatic compound allows an optional stage in which the charged raw materials are reduced, but the conversion rate of DHA is 50% or more. The above stage is preferable, and a stage of 70% or more is more preferable. By adding at such a stage, it becomes possible to obtain cyclic PAS more efficiently.

  In addition, when the amount of water in the reaction mixture changes due to the addition of the raw material, it is also possible to perform an additional operation so as to achieve the above-described preferable amount of water. It is also desirable to later remove any amount of water from the reaction mixture. 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. The reaction pressure is not particularly limited because it cannot be defined unconditionally depending on the type and amount of the raw material and solvent used, or the reaction temperature.

(7) Method for recovering cyclic polyarylene sulfide In the production of cyclic PAS of the present invention, cyclic PAS can be separated and recovered from the reaction mixture obtained by the above-described reaction. The reaction mixture obtained by the reaction contains cyclic PAS, linear PAS, and organic polar solvent, and other components include unreacted sulfidizing agent, dihalogenated aromatic compound, water, by-product salt, etc. There is also.

(7-1) Recovery method 1 of cyclic polyarylene sulfide
There is no particular limitation on the method for recovering the PAS component from such a reaction mixture. For example, if necessary, after removing a part or most of the organic polar solvent by an operation such as distillation, the solubility in the PAS component is low and A method of recovering a PAS component as a mixed solid with a linear PAS by mixing with an organic polar solvent, preferably contacting with a solvent having solubility in a by-product salt, if necessary, under heating The solid and soluble components present in the reaction mixture at a temperature sufficient to dissolve the cyclic PAS and linear PAS in the reaction mixture, preferably above 200 ° C., more preferably above 230 ° C. A solution component containing at least cyclic PAS, linear PAS, and organic polar solvent is recovered by separation, and one of the organic polar solvents is collected from this solution component as necessary. Alternatively, after most of the components are removed by an operation such as distillation, they are poorly soluble in the PAS component and mixed with an organic polar solvent, preferably in contact with a solvent that is soluble in by-product salts, if necessary under heating. And a method of recovering the PAS component as a mixed solid with cyclic PAS and linear PAS. Solvents having such properties are generally relatively polar solvents, and the preferred solvent varies depending on the type of organic polar solvent and by-product salt used, but can not be limited. For example, water, methanol, ethanol, propanol, Examples include alcohols typified by isopropanol, butanol and hexanol, ketones typified by acetone, and acetates typified by ethyl acetate and butyl acetate. From the viewpoint of availability and economy, water, methanol and acetone Are preferred, and water is particularly preferred.

  By performing the treatment with such a solvent, it is possible to reduce the amount of the organic polar solvent or by-product salt contained in the mixed solid of cyclic PAS and linear PAS. Since cyclic PAS and linear PAS are both precipitated as a solid component by this treatment, the PAS component can be recovered as a mixture of cyclic PAS and linear PAS using a known solid-liquid separation method. Examples of the solid-liquid separation method include separation by filtration, centrifugation, and decantation. Note that a series of these treatments can be repeated several times as necessary, which further reduces the amount of organic polar solvent and by-product salt contained in the mixed solid of cyclic PAS and linear PAS. Tend to.

  Moreover, as a method of the treatment with the above-mentioned solvent, there is a method of mixing a solvent and a reaction mixture, and it is possible to appropriately stir or heat as necessary. Although there is no restriction | limiting in particular in the temperature at the time of performing the process by a solvent, 20 to 220 degreeC is preferable and 50 to 200 degreeC is still more preferable. In such a range, for example, by-product salt can be easily removed, and the treatment can be performed at a relatively low pressure, which is preferable. Here, when water is used as the solvent, the water is preferably distilled water or deionized water, but if necessary, formic acid, acetic acid, propionic acid, butyric acid, chloroacetic acid, dichloroacetic acid, acrylic acid, crotonic acid, Organic acidic compounds such as benzoic acid, salicylic acid, oxalic acid, malonic acid, succinic acid, phthalic acid, fumaric acid, and their alkali metal salts, alkaline earth metal salts, sulfuric acid, phosphoric acid, hydrochloric acid, carbonic acid, silicic acid, etc. It is also possible to use an aqueous solution containing a compound and ammonium ions. When the mixed solid of cyclic PAS and linear PAS obtained after this treatment contains the solvent used in the treatment, it can be dried as necessary to remove the solvent.

  In the recovery method exemplified above, cyclic PAS is recovered as a mixture with linear PAS (hereinafter also referred to as a PAS mixture). As a method for separating cyclic PAS and linear PAS, for example, a separation method using the difference in solubility between cyclic PAS and linear PAS, more specifically, high solubility in cyclic PAS, An example is a method of obtaining cyclic PAS as a solvent-soluble component by bringing a solvent having poor solubility in linear PAS into contact with a PAS mixture under heating as necessary under conditions for dissolving cyclic PAS. Here, in the method for producing the cyclic PAS of the present invention, as described above, the linear PAS contained in the PAS mixture is easily obtained as a high molecular weight product. Since the difference in solubility is large, it is possible to efficiently obtain cyclic PAS by the separation method using the above-described solubility. The molecular weight of the linear PAS is preferably a molecular weight that is difficult to dissolve in a solvent capable of dissolving cyclic PAS, which will be described later, and preferably has a property of not dissolving, and the weight average molecular weight can be exemplified by 2,500 or more, and 5,000 The above is preferable, and 10,000 or more can be illustrated more preferably.

  The solvent used for separation of cyclic PAS and linear PAS is not particularly limited as long as it is a solvent capable of dissolving cyclic PAS, but cyclic PAS dissolves but linear PAS hardly dissolves in the dissolving environment. A solvent is preferable, and a solvent that does not dissolve linear PAS is more preferable. The pressure of the reaction system when the PAS mixture is brought into contact with the solvent is preferably normal pressure or slight pressure, and particularly preferably normal pressure, and the reaction system of such pressure is inexpensive for the components of the reactor for constructing it. There are advantages. From this point of view, it is desirable that the reaction system pressure avoid pressurizing conditions that require an expensive pressure vessel. As the solvent to be used, those which do not substantially cause undesirable side reactions such as decomposition and crosslinking of the PAS component are preferable. For example, when the operation of bringing the PAS mixture into contact with the solvent is performed under atmospheric pressure reflux conditions, Hydrocarbon solvents such as pentane, hexane, heptane, octane, cyclohexane, cyclopentane, benzene, toluene, xylene, chloroform, bromoform, methylene chloride, 1,2-dichloroethane, 1,1,1-trichloroethane, chlorobenzene, 2, Halogen solvents such as 6-dichlorotoluene, ether solvents such as diethyl ether, tetrahydrofuran, diisopropyl ether, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, trimethyl phosphoric acid, N, N-di Examples include polar solvents such as tilimidazolidinone and methyl ethyl ketone, among which benzene, toluene, xylene, chloroform, bromoform, methylene chloride, 1,2-dichloroethane, 1,1,1-trichloroethane, chlorobenzene, 2,6-dichloro Toluene, diethyl ether, tetrahydrofuran, diisopropyl ether, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, trimethyl phosphoric acid, N, N-dimethylimidazolidinone, methyl ethyl ketone are preferred, toluene, xylene, chloroform, More preferable examples include methylene chloride, tetrahydrofuran, and methyl ethyl ketone.

  There are no particular restrictions on the atmosphere in which the PAS mixture is brought into contact with the solvent, but if the PAS component or solvent is subject to oxidative degradation due to conditions such as temperature or time at the time of contact, it should be performed in a non-oxidizing atmosphere Is desirable. Note that 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 such as nitrogen, helium, argon, or the like. Among these, a nitrogen atmosphere is particularly preferable from the viewpoints of economy and ease of handling.

  There is no particular restriction on the temperature at which the PAS mixture is brought into contact with the solvent, but generally, the higher the temperature, the more the dissolution of cyclic PAS in the solvent tends to be accelerated, but when the molecular weight of linear PAS is low, the linear PAS Dissolution also tends to be accelerated. When the molecular weight of the linear PAS is the above-described preferable molecular weight, the difference in solubility with the cyclic PAS increases, so that even if the PAS mixture is contacted with the solvent at a high temperature, the cyclic PAS and the linear PAS are increased. Tends to be suitably separated. Further, as described above, since the contact of the PAS mixture with the solvent is preferably performed under atmospheric pressure, the upper limit temperature is preferably set to the reflux condition temperature under the atmospheric pressure of the solvent used. When a preferable solvent is used, for example, 20 to 150 ° C, preferably 30 to 100 ° C can be exemplified as a specific temperature range.

  The time for which the PAS mixture is brought into contact with the solvent varies depending on the type of solvent used, the temperature, etc., and therefore cannot be uniquely limited. For example, 1 to 50 hours can be exemplified, and in such a range, the cyclic PAS is dissolved in the solvent. Tend to be sufficient.

  The method of bringing the PAS mixture into contact with the solvent is not particularly limited as long as a known general method is used. For example, the PAS mixture and the solvent are mixed, and if necessary, the solution portion is recovered after being stirred. Any method can be used, such as a method of dissolving cyclic PAS in a solvent simultaneously with showering a solvent in the PAS mixture on the filter, or a method based on the principle of Soxhlet extraction. Although there is no restriction | limiting in particular in the usage-amount of the solvent at the time of making a PAS mixture and a solvent contact, For example, the range of 0.5-100 can be illustrated by the bath ratio with respect to a PAS mixture weight. When the bath ratio is in such a range, the PAS mixture and the solvent are easily mixed uniformly, and the cyclic PAS tends to be sufficiently dissolved in the solvent. In general, a larger bath ratio is advantageous for dissolving cyclic PAS in a solvent, but if it is too large, no further effect can be expected, and conversely an economic disadvantage due to an increase in the amount of solvent used may occur. is there. When the contact between the PAS mixture and the solvent is repeated, a sufficient effect is often obtained even with a small bath ratio. In addition, the Soxhlet extraction method, in principle, provides an effect similar to that obtained when the contact of the PAS mixture and the solvent is repeated, and in this case, a sufficient effect can often be obtained with a small bath ratio.

  After the PAS mixture is brought into contact with a solvent, when the solution in which the cyclic PAS is dissolved is obtained in the form of a solid-liquid slurry containing solid linear PAS, the solution part is recovered using a known solid-liquid separation method. It is preferable. Examples of the solid-liquid separation method include separation by filtration, centrifugation, and decantation. By removing the solvent from the solution thus separated, the cyclic PAS can be recovered. On the other hand, for the solid component, when the cyclic PAS still remains, it is possible to obtain the cyclic PAS with higher yield by repeating contact with the solvent and recovery of the solution again. The solid content obtained after separation of the cyclic PAS solution by this operation is valuable for use as a high-purity linear PAS mainly composed of linear PAS. It can be suitably used again as a raw material for the cyclic PAS of the present invention after treatment such as removal of the residual solvent.

  It is also possible to remove the solvent from the solution containing cyclic PAS obtained as described above to obtain cyclic PAS as a solid component. Here, the removal of the solvent can be exemplified by, for example, a method of heating and treating at normal pressure or less, and removal of the solvent using a membrane, but the viewpoint of obtaining the cyclic polyarylene sulfide more efficiently and efficiently. Then, a method of removing the solvent by heating at normal pressure or lower is preferable. The solution containing the cyclic PAS obtained as described above may contain a solid depending on the temperature. In this case, the solid belongs to the cyclic polyarylene sulfide mixture. It is desirable to recover together with components that are soluble in the solvent at the time of removal, so that cyclic PAS can be obtained with good yield. Here, it is desirable to remove the solvent at least 50% by weight or more, preferably 70% by weight or more, more preferably 90% by weight or more, and still more preferably 95% by weight or more. Although the temperature at which the solvent is removed by heating depends on the characteristics of the solvent used, it cannot be limited uniquely. However, the temperature can usually be selected from 20 to 150 ° C, preferably from 40 to 120 ° C. In addition, the pressure for removing the solvent is preferably normal pressure or lower, which makes it possible to remove the solvent at a lower temperature.

(7-2) Cyclic polyarylene sulfide recovery method 2
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 sulfidizing agent, dihalogenated aromatic compound, water, by-product salt, etc. As described above, cyclic PAS tends to be dissolved in an organic polar solvent in a wide temperature range in this reaction mixture. On the other hand, the present inventors have found that linear PAS is greatly different from cyclic PAS in dissolution behavior, and specifically, most of the linear PAS tends to exist as a solid in the reaction mixture in the temperature range of 200 ° C. or lower. It was.

  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 further 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 weight average molecular weight PAS tends to become a solid content under these conditions. On the other hand, the cyclic PAS in the reaction mixture tends to be soluble in an organic polar solvent in this preferred temperature range. 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 separability between the solid component and the solution component tends to be excellent.

  In the above-described solid-liquid separation of the reaction mixture, it is possible to obtain linear PAS as a solid content, but it is difficult to completely separate the solid content and the liquid content as in the case of general solid-liquid separation. The solid content is separated as a liquid component such as an organic polar solvent in the reaction mixture. Therefore, if desired, a wet linear PAS in which the organic polar solvent derived from the reaction mixture is reduced by solvent replacement with a fresh solvent (not necessarily the organic polar solvent used in the reaction) is used. It is also possible to obtain a linear PAS in a dry state by additionally performing an operation of removing the liquid component contained. The dried linear PAS thus obtained can also be used as the linear PAS (a) which is the reaction raw material of the present invention. Also, a wet linear PAS containing an organic polar solvent derived from the reaction mixture, or a wet linear PAS subjected to solvent replacement using an additional fresh solvent can be used in the wet state. It can also be used as linear PAS (a) as a reaction raw material, and in this case, it can be said to be a more preferable method from the viewpoint that the liquid component removal step can be omitted.

  Moreover, cyclic PAS is contained in the solution component obtained by solid-liquid separation of the reaction mixture mentioned above, ie, a filtrate component (it may contain a solid component depending on temperature). If desired, the organic polar solvent can be removed from the filtrate components to recover as a solid containing cyclic PAS. Examples of the method for removing the organic polar solvent include a method of removing by distillation and a method of contacting with a second solvent miscible with the organic polar solvent. 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 a heating in non-oxidizing atmosphere, and 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 of obtaining cyclic PAS by solvent replacement of the filtrate component with a second solvent, contact with a second solvent in which cyclic PAS does not dissolve or cyclic PAS is difficult to dissolve, A method for recovering a solid component containing cyclic PAS can be exemplified. As a more specific method of contacting with the second solvent, it is possible to exemplify adopting a method shown in (8) described later.

(8) Other post-treatments The cyclic polyarylene sulfide thus obtained has a sufficiently high purity and can be suitably used for various applications. However, the post-treatment described below is further applied to further increase the purity. High cyclic PAS can be obtained.

  The cyclic PAS obtained by the operations up to (7) 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 in which cyclic PAS is difficult to dissolve, thereby selectively removing impurity components. Often it is possible to do. It is also possible to bring the second solvent into contact with the filtrate component in order to separate cyclic PAS as a solid component from the filtrate component (solution containing cyclic PAS) obtained by the method (7-2). is there.

  The reaction system pressure when the cyclic PAS mixture or the filtrate component obtained in the above (7-2) is contacted with the second solvent is preferably normal pressure or slight pressure, and particularly preferably normal pressure. The pressure reaction system has the advantage that the components that build it are inexpensive. From this point of view, it is desirable that the reaction system pressure avoid pressurizing conditions that require an expensive pressure vessel. As the preferred solvent as the second solvent, those which do not substantially cause undesirable side reactions such as decomposition and crosslinking of cyclic PAS are preferable. For example, methanol, ethanol, propanol, butanol, pentanol, ethylene glycol, propylene glycol, Alcohol / phenol solvents such as 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, acetophenone, etc. Ketone solvents such as methyl acetate, ethyl acetate, pentyl acetate, octyl acetate, methyl butyrate, ethyl butyrate, pentyl butyrate, methyl salicylate, ethyl formate, etc. Examples thereof 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.

  There is no particular limitation on the temperature at which the cyclic PAS is brought into contact with the second solvent, but the upper limit temperature is desirably the reflux condition temperature under normal pressure of the second solvent to be used. When using, 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 varies depending on the type of solvent used, the temperature, etc., and therefore cannot be uniquely limited. For example, it can be exemplified by 1 minute to 50 hours. There is a tendency for the impurities in the formula PAS to be sufficiently dissolved in the second solvent.

  As a method of bringing the cyclic PAS into contact with the second solvent, a method in which the solid cyclic PAS and the second solvent are mixed with stirring as necessary, and the second solvent is added to the cyclic PAS solid on various filters. A method of dissolving impurities in a second solvent at the same time as showering, a method using Soxhlet extraction of a solid cyclic PAS using a second solvent, a cyclic PAS or a cyclic PAS slurry containing a solvent For example, a method in which cyclic PAS is precipitated in the presence of the second solvent by contacting with the second solvent can be used. In particular, the method of bringing a cyclic PAS slurry containing a solvent into contact with a second solvent is an effective method because the cyclic PAS obtained after the operation has a high purity.

  After contacting the cyclic PAS with the second solvent, 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 the solid-liquid separation, the cyclic PAS and the second solvent can be contacted again to further remove the impurities.

(9) Characteristics 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. Further, the cyclic PAS obtained by the production method of the present invention is characterized in that m in the formula (Q) is not single, and the formula (Q) having m of 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 in this range, as will be described later, when cyclic PAS is used for ring-opening polymerization, 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 this time, but it is assumed that cyclic PAS in this range has a large bond distortion due to the fact that the molecule is cyclic, and that a ring-opening reaction easily occurs 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.

(10) 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 (Q) 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 the melting point is exceeded. 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. Although an upper limit is not specifically limited, It is preferable that it is 300 degrees C or less from points, such as a moldability, and it is more preferable that it is 280 degrees C or less. 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 (Q) as the cyclic PAS. When a cyclic PAS is used alone, that is, when m in the formula (Q) is single, such a cyclic PAS tends to have a high melting point. When kneading, the cyclic PAS having a different m in the formula (Q) has a melting temperature as described above. This tends to be low, and this is effective in improving 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 (Q) is not single, and the formula (Q) having m different from m = 4 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.

(11) 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 (9), and therefore, as a prepolymer for obtaining a polymer by ring-opening polymerization. It can be suitably used. 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 ring-opening polymerization of the cyclic PAS may be carried out under conditions where the ring-opening of the cyclic PAS occurs and a high molecular weight product is formed. For example, a PAS prepolymer containing a cyclic PAS by the cyclic PAS production method of the present invention may be used. A method of heating to convert to a high degree of polymerization can be exemplified as a preferred 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. 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 desirable to use as little as possible, preferably not, a catalyst component. 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.

  The conversion of the PAS prepolymer to a high degree of polymerization by heating is usually carried out in the absence of a solvent, but can also be carried out 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. Note that 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 preferable upper limit, an undesirable side reaction such as a crosslinking reaction tends to easily occur. On the other hand, when the pressure reduction condition is less than the preferable lower limit, a cyclic polyarylene sulfide having a low molecular weight contained in the PAS prepolymer is formed depending on the reaction temperature. It tends to evaporate easily.

  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. Within this length range, the strength of the reinforcing fiber can be easily expressed 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, even if it is a single direction, a random direction, a sheet form, a mat form, a textile form, and a braid form, it can be used. 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.

(12) PAS
According to the above (11), it is possible to obtain an industrially very useful PAS. Here, PAS is a homopolymer or copolymer having a repeating unit of the formula, — (Ar—S) —, as the main constituent unit, and preferably containing 80 mol% or more of the repeating unit. Ar can be exemplified by units represented by the above formulas (A) to (L), among which the formula (A) is particularly preferable.

  As long as this repeating unit is a main structural unit, it may contain a small amount of a branch unit or a crosslinking unit represented by the above formula (M) to formula (O), etc. The polymerization amount is preferably in the range of 0 to 1 mol% with respect to 1 mol of-(Ar-S)-units.

  Further, the PAS obtained according to a preferred embodiment of 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 includes 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.

  Although there is no restriction | limiting in particular in the molecular weight of PAS obtained by the preferable aspect of this invention, As a preferable range, it is 10,000 or more in weight average molecular weight, More preferably, it is 15,000 or more, More preferably, it is 18,000 or more. PAS having a weight average molecular weight of 10,000 or more tends to have high moldability at the time of processing and high properties such as mechanical strength and chemical resistance of the molded product. Although there is no restriction | limiting in particular in the upper limit of a weight average molecular weight, Less than 1,000,000 can be illustrated as a preferable range, More preferably, it is less than 500,000, More preferably, it is less than 200,000. Sex can be obtained.

  The degree of dispersion represented by the spread of the molecular weight distribution of PAS obtained by a preferred embodiment of the present invention, that is, the ratio of the weight average molecular weight to the number average molecular weight (weight average molecular weight / number average molecular weight) is 4.0 or less. 0.5 or less is preferable, 2.3 or less is more preferable, 2.1 or less is more preferable, and 2.0 or less is even more preferable. PAS with a dispersity of 4.0 or less tends to have a small amount of low-molecular components contained in PAS. Within this range, PAS has high mechanical properties when used for molding processing, and gas when heated There is a tendency that the amount of the generated component and the amount of the eluted component when in contact with the solvent can be reduced. The weight average molecular weight and number average molecular weight can be determined using, for example, SEC (size exclusion chromatography) equipped with a differential refractive index detector.

  Further, the melt viscosity of the PAS obtained by the preferred embodiment of the present invention is not particularly limited, but usually, the melt viscosity is in the range of 5 to 10,000 Pa · s (300 ° C., shear rate 1000 / sec) as a preferred range. it can.

  According to a preferred embodiment of the present invention, the obtained PAS has a higher purity than the conventional one, and the alkali metal content as an impurity is easily obtained at 100 ppm or less. The preferred alkali metal content is less than 50 ppm, more preferably 30 ppm or less, and still more preferably 10 ppm or less. When the alkali metal content is 100 ppm or less, for example, high reliability is easily exhibited in applications requiring high electrical insulation characteristics. Here, the alkali metal content of PAS in the present invention is a value calculated from, for example, the amount of alkali metal in ash, which is a residue obtained by baking PAS using an electric furnace or the like. It can be quantified by analyzing by an atomic absorption method.

Another feature of the PAS obtained by the preferred embodiment of the present invention is that the weight loss upon heating is significantly less than that of the conventional PAS, and specifically, tends to satisfy the following formula (1).
ΔWr = (W1-W2) /W1×100≦0.18 (%) (1)

  Here, ΔWr is a weight reduction rate (%), and when thermogravimetric analysis was performed at a temperature increase rate of 20 ° C./min from 50 ° C. to an arbitrary temperature of 330 ° C. or higher in a non-oxidizing atmosphere at normal pressure. The value obtained from the sample weight (W2) when reaching 330 ° C. with reference to the sample weight (W1) when reaching 100 ° C.

  The PAS obtained according to the preferred embodiment of the present invention has a strong tendency that ΔWr is 0.18% or less and is extremely small, preferably 0.15% or less, more preferably 0.12% or less. Tend to have. ΔWr is in the above range, for example, there is a tendency to reduce the amount of gas generated when molding PAS, and there is a deposit on the die or die during extrusion molding or the mold during injection molding. It tends to be reduced and productivity is improved. As far as the present inventors know, ΔWr of the known PAS exceeds 0.18%, but the PAS obtained by the preferred embodiment of the present invention tends to be extremely high in purity, unlike the known PAS in terms of molecular weight distribution and impurity content. Therefore, it is presumed that the value of ΔWr is remarkably lowered.

  ΔWr can be obtained by a general thermogravimetric analysis, and the atmosphere in this analysis is a normal pressure non-oxidizing atmosphere. A non-oxidizing atmosphere is an atmosphere in which the oxygen concentration in the gas phase in contact with the sample is 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 A nitrogen atmosphere is particularly preferred from the standpoints of economy and ease of handling. 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 about 25 ° C. and the absolute pressure is about 101.3 kPa. If the measurement atmosphere is other than the above, there is a possibility that the measurement cannot be in line with the actual use of the PAS, such as oxidation of the PAS during the measurement or greatly different from the atmosphere actually used in the PAS molding process. . In the measurement of ΔWr, thermogravimetric analysis is performed by increasing the temperature from 50 ° C. to an arbitrary temperature of 330 ° C. or higher at a temperature increase rate of 20 ° C./min. Preferably, after holding at 50 ° C. for 1 minute, the temperature is increased at a rate of temperature increase of 20 ° C./min to perform thermogravimetric analysis. This temperature range is a temperature range frequently used when actually using a PAS represented by polyphenylene sulfide, and is also a temperature range frequently used when a solid state PAS is melted and then molded into an arbitrary shape. is there. The weight reduction rate in the actual use temperature region is related to the amount of gas generated from the PAS during actual use, the amount of components adhering to the die or mold during molding, and the like. Therefore, it can be said that a PAS having a lower weight loss rate in such a temperature range is an excellent PAS having a high quality. It is desirable to measure ΔWr with a sample amount of about 10 mg, and the shape of the sample is desirably a fine particle of about 2 mm or less.

(13) Characteristics of PAS PAS obtained by a preferred embodiment of the present invention is excellent in heat resistance, chemical resistance, flame retardancy, electrical properties and mechanical properties, and in particular has a narrow molecular weight distribution compared to conventional PAS, In addition, since the metal content tends to be extremely low, the molding processability, mechanical properties, and electrical properties are extremely excellent. Sheets and films can be used not only for injection molding, injection compression molding, and blow molding, but also by extrusion molding. It can be molded and used for extruded products such as fibers and pipes.

  As a method for producing a PAS film using a PAS obtained according to a preferred embodiment of the present invention, a known melt film-forming method can be employed. For example, after melting PAS in a single-screw or twin-screw extruder, A method of producing a film by extruding from a film die and cooling on a cooling drum, or biaxial stretching in which a film thus produced is stretched longitudinally and laterally by a roller type longitudinal stretching apparatus and a transverse stretching apparatus called a tenter. Although a law etc. can be illustrated, it is not specifically limited to this.

  As a method for producing a PAS fiber using the PAS obtained according to the preferred embodiment of the present invention, a known melt spinning method can be applied. For example, a raw material PAS chip is supplied to a single-screw or twin-screw extruder. It is possible to employ a method of kneading while extruding, then extruding from a spinneret through a polymer stream line changer installed at the tip of the extruder, a filtration layer, etc., cooling, stretching, and heat setting. It is not limited to.

  In addition, the PAS obtained according to the preferred embodiment of the present invention may be used alone or, if desired, an inorganic filler such as glass fiber, carbon fiber, titanium oxide, calcium carbonate, antioxidant, heat stabilizer. UV absorbers, colorants, etc. can also be added. Polyamide, polysulfone, polyphenylene ether, polycarbonate, polyethersulfone, polyester represented by polyethylene terephthalate and polybutylene terephthalate, polyethylene, polypropylene, polytetrafluoroethylene, epoxy Group, carboxyl group, carboxylic acid ester group, olefin copolymer having functional group such as acid anhydride group, polyolefin elastomer, polyether ester elastomer, polyether amide elastomer, polyamide imide Polyacetals can also be blended resin such as polyimide.

(14) Use of PAS Examples of excellent properties of PAS obtained by a preferred embodiment of the present invention include molding processability, mechanical properties, and electrical properties. Examples of uses thereof include sensors, LED lamps, connectors, sockets, and resistors. , Relay case, switch, coil bobbin, condenser, variable capacitor case, optical pickup, oscillator, various terminal boards, transformer, plug, printed circuit board, tuner, speaker, microphone, headphones, small motor, magnetic head base, power module, Electrical and electronic parts represented by semiconductors, liquid crystal, FDD carriages, FDD chassis, motor brush holders, parabolic antennas, computer-related parts, etc .; VTR parts, TV parts, irons, hair dryers, rice cooker parts, microwave oven parts Audio / laser discs (registered trademark), audio / video equipment parts such as compact discs and digital video discs, lighting parts, refrigerator parts, air conditioner parts, typewriter parts, word processor parts, etc. Electrical product parts: Office computer-related parts, telephone-related parts, facsimile-related parts, copier-related parts, cleaning jigs, motor parts, lighters, typewriters and other machine-related parts: microscopes, binoculars, cameras, Optical equipment such as watches, precision machinery-related parts; water faucet tops, mixing faucets, pump parts, pipe joints, water volume control valves, relief valves, hot water temperature sensors, water volume sensors, water meter housings ; Valve alternator terminal, alternator connector , IC regulator, light dimmer potentiometer base, various valves such as exhaust gas valves, fuel-related / exhaust / intake system pipes, air intake nozzle snorkel, intake manifold, fuel pump, engine coolant joint, carburetor main body , Carburetor spacer, exhaust gas sensor, cooling water sensor, oil temperature sensor, throttle position sensor, crankshaft position sensor, air flow meter, brake pad wear sensor, thermostat base for air conditioner, heating hot air flow control valve, brush for radiator motor Holder, water pump impeller, turbine vane, wiper motor related parts, distributor, starter switch Starter relay, wire harness for transmission, window washer nozzle, air conditioner panel switch board, coil for fuel-related electromagnetic valve, fuse connector, horn terminal, electrical component insulation plate, step motor rotor, lamp socket, lamp reflector, lamp housing, brake Examples include pistons, solenoid bobbins, engine oil filters, fuel tanks, ignition device cases, vehicle speed sensors, cable liners and other automobile / vehicle-related parts, and various other applications.

  In the case of PAS film, it has excellent mechanical properties, electrical properties, and heat resistance. It is used for dielectric films of film capacitors and chip capacitors, for circuit boards, insulating substrates, for motor insulating films, for transformer insulating films, for separation. It can be suitably used for various applications such as mold film applications.

  In the case of PAF monofilament or short fiber, it can be suitably used for various applications such as paper-making dryer canvas, net conveyor, bag filter, insulating paper.

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

<Molecular weight measurement>
The molecular weight of the polyarylene sulfide and the polyarylene sulfide prepolymer was calculated in terms of polystyrene by gel permeation chromatography (GPC) which is a kind of size exclusion chromatography (SEC). The measurement conditions for GPC are shown below.
Equipment: Senshu Science SSC-7100
Column name: Senshu Science GPC3506
Eluent: 1-chloronaphthalene detector: differential refractive index detector Column temperature: 210 ° C
Pre-constant temperature: 250 ° C
Pump bath temperature: 50 ° C
Detector temperature: 210 ° C
Flow rate: 1.0 mL / min
Sample injection amount: 300 μL (slurry: about 0.2% by weight)

<Measurement of cyclic polyphenylene sulfide production rate>
The production rate of the cyclic polyphenylene sulfide compound was subjected to qualitative quantitative analysis using HPLC. The measurement conditions for HPLC are shown below.
Apparatus: Shimadzu Corporation LC-10Avp series Column: Mightysil RP-18 GP150-4.6 (5 μm)
Detector: Photodiode array detector (UV = 270 nm)

[Reference Example 1]
Here, an example is shown in which linear PAS is produced by the prior art, that is, linear PAS is produced by contacting a sulfidizing agent and a dihalogenated aromatic compound in an organic polar solvent.

  In a stainless steel autoclave equipped with a stirrer, 116.9 g (1.00 mol) of a 48 wt% aqueous solution of sodium hydrosulfide, 43.8 g (1.05 mol) of 96% sodium hydroxide, N-methyl-2-pyrrolidone (NMP) 198.3 g (2.00 mol), 8.2 g (0.10 mol) of sodium acetate, and 150 g of ion-exchanged water were charged. After attaching the rectifying column to the autoclave, stirring was started at 240 rpm, and the mixture was gradually heated to an internal temperature of 235 ° C. over about 3 hours while passing nitrogen at normal pressure. During this time, 212 g was distilled out of the rectification column. The amount of hydrogen sulfide scattered was 0.012 mol. In addition, as a result of analyzing the distillate by gas chromatography, it was found to be a mixed solution of 209 g of water and 3.5 g of NMP, and the amounts of water and NMP in the reaction system were 2.3 g and 194.8 g, respectively. .

  After completion of the distillation, the reaction vessel was cooled to about 160 ° C., and 148.5 g (1.01 mol) of p-dichlorobenzene (p-DCB) and 99.1 g (1.00 mol) of NMP were further added. Was sealed under nitrogen gas. While stirring at 400 rpm, the temperature was raised to 200 ° C. over about 30 minutes, and then the temperature was raised from 200 ° C. to 270 ° C. at a rate of 0.6 ° C./minute, and the reaction was continued at 270 ° C. for 140 minutes. Thereafter, 36 g (2.00 mol) of water was poured into the system while cooling to 250 ° C. over 15 minutes, and then cooled from 250 ° C. to 220 ° C. at a rate of 0.4 ° C./min. Thereafter, it was rapidly cooled to near room temperature.

  The contents were taken out, diluted with 500 g of NMP to form a slurry, and stirred at 85 ° C. for about 30 minutes, and then the slurry was filtered through a stainless 80 mesh sieve to recover the solid content. 400 g of NMP was added to the obtained solid content, and the mixture was stirred at 85 ° C. for about 30 minutes, followed by filtration in the same manner to recover the solid content. Thereafter, the operations of stirring, washing and filtering with 800 g of warm water were repeated 5 times to obtain a granular solid. This was dried with hot air at 60 ° C. and then dried under reduced pressure at 120 ° C. to obtain about 90 g of a dry solid.

  As a result of analyzing the solid thus obtained, it was found from the absorption spectrum in infrared spectroscopic analysis (apparatus; FTIR-8100A manufactured by Shimadzu Corp.) that it was a linear polyphenylene sulfide. The weight average molecular weight was 38,600. The polyphenylene sulfide obtained here is hereinafter referred to as linear PPS-1.

[Reference Example 2]
Here, the cyclic PAS obtained by reacting the sulfidizing agent and the dihalogenated aromatic compound by heating using 1.25 liters or more of an organic polar solvent with respect to 1 mol of the sulfur component of the sulfidizing agent and linear An example in which linear PAS having a molecular weight lower than that of Reference Example 1 was produced by a method of separating cyclic PAS from a PAS mixture containing linear PAS is shown.

  A stainless steel autoclave equipped with a stirrer was charged with 14.03 g (0.120 mol) of a 48 wt% aqueous solution of sodium hydrosulfide and 12.50 g (0.144 mol) of a 48 wt% aqueous solution prepared using 96% sodium hydroxide. ), 615.0 g (6.20 mol) of NMP, and 18.08 g (0.123 mol) of p-DCB. The reaction vessel was sufficiently purged with nitrogen, and then sealed under nitrogen gas.

  While stirring at 400 rpm, the temperature was raised from room temperature to 200 ° C. over about 1 hour. At this stage, the pressure in the reaction vessel was 0.35 MPa as a gauge pressure. Next, the temperature was raised from 200 ° C. to 270 ° C. over about 30 minutes. The pressure in the reaction vessel at this stage was 1.05 MPa as a gauge pressure. After maintaining at 270 ° C. for 1 hour, the contents were recovered after quenching to near room temperature.

  The content obtained was analyzed by gas chromatography and high performance liquid chromatography. As a result, the consumption rate of monomer p-DCB was 93%, and the sulfur content in the reaction mixture was assumed to be all converted to cyclic PPS. The formula PPS production rate was found to be 18.5%.

  500 g of the obtained content was diluted with about 1500 g of ion-exchanged water, and then filtered through a glass filter having an average opening of 10 to 16 micrometers. The filter-on component was dispersed in about 300 g of ion-exchanged water, stirred at 70 ° C. for 30 minutes, and filtered again in the same manner three times to obtain a white solid. This was vacuum dried at 80 ° C. overnight to obtain a dry solid.

  The obtained solid matter was charged into a cylindrical filter paper, and Soxhlet extraction was performed for about 5 hours using chloroform as a solvent to remove low molecular weight components contained in the solid content.

  The solid component remaining in the cylindrical filter paper after the extraction operation was dried under reduced pressure at 70 ° C. overnight to obtain about 6.98 g of an off-white solid. As a result of the analysis, this was a linear polyphenylene sulfide and the weight average molecular weight was 6,300 from the absorption spectrum in the infrared spectroscopic analysis. The polyphenylene sulfide obtained here is hereinafter referred to as linear PPS-2.

[Reference Example 3]
After removing the solvent from the extract obtained by the chloroform extraction operation of Reference Example 2, about 5 g of chloroform was added to prepare a slurry, which was added dropwise to about 300 g of methanol with stirring. The precipitate thus obtained was collected by filtration and vacuum dried at 70 ° C. for 5 hours to obtain 1.19 g of a white powder. This white powder was confirmed to be a compound composed of phenylene sulfide units from an absorption spectrum in infrared spectroscopic analysis. Moreover, this white powder is a cyclic polyphenylene having 4 to 12 repeating units based on molecular weight analysis of the components separated by high performance liquid chromatography (apparatus; Hitachi M-1200H) and molecular weight information by MALDI-TOF-MS. It was a mixture containing sulfide as a main component, and the weight fraction of cyclic polyphenylene sulfide was found to be about 90%.

  The yield of white powder was 20.8%, assuming that all sulfur components present in the reaction system during the reaction were converted to PPS components.

[Example 1]
In a stainless steel autoclave equipped with a stirrer, 6.49 g of the linear PPS-1 obtained in Reference Example 1 (0.0601 mol of sulfur component) and 0.711 g of sodium 48% by weight aqueous solution of sodium hydrosulfide (sodium hydrosulfide) 0.341 g (0.00608 mol), water 0.370 g (0.0205 mol)), and a 48 wt% aqueous solution prepared using 96% pure sodium hydroxide 0.649 g (sodium hydroxide 0.299 g (0.00748 mol)) ), 0.337 g (0.0187 mol) of water, 615 g (6.21 mol) of N-methyl-2-pyrrolidone (NMP), and 0.894 g (0.00608 mol) of p-dichlorobenzene (p-DCB). . The total amount of sulfur components derived from linear PPS-1 and sodium hydrosulfide was 0.0662 mol, and the amount of solvent per mol of sulfur component in the reaction mixture was about 9.07 L.

  The reaction vessel was sealed under nitrogen gas at room temperature and normal pressure, and then heated from room temperature to 200 ° C. over about 1 hour with stirring at 400 rpm. Subsequently, it heated up to 270 degreeC over about 0.5 hour. The pressure in the reaction system at this stage was 0.6 MPa as a gauge pressure. After holding at 270 ° C. for 1 hour, it was rapidly cooled to near room temperature.

  As a result of analyzing the obtained contents by gas chromatography and high performance liquid chromatography, the consumption rate of monomer p-DCB was 58.1%, and the production rate of cyclic PAS with respect to the charged monomer (p-DCB) was about It was found that the yield of cyclic PAS was 23.1%, assuming 251% and all sulfur components in the reaction mixture were converted to cyclic PAS.

  According to the method for producing cyclic PAS of the present invention, it was found that the cyclic PAS formation reaction proceeds in a short time, and a larger amount of cyclic PAS than that of the charged monomer can be obtained. This suggests that part of the charged linear PPS was converted to cyclic PAS during the reaction, and it was found that cyclic PAS can be obtained with high efficiency in the present invention.

[Example 2]
In a stainless steel autoclave equipped with a stirrer, 6.52 g (sulfur component amount 0.0604 mol) of linear PPS-1 obtained in Reference Example 1, 0.279 g (0.00608 mol) of anhydrous lithium sulfide, lithium hydroxide 0.0421 g (0.00176 mol), NMP 616 g (6.22 mol), and p-DCB 0.894 g (0.00608 mol) were charged. The total of sulfur components derived from linear PPS-1 and lithium sulfide was 0.0665 mol, and the amount of solvent per mole of sulfur component in the reaction mixture was about 9.04 L.

  The reaction vessel was sealed under nitrogen gas at room temperature and normal pressure, and then heated from room temperature to 200 ° C. over about 1 hour with stirring at 400 rpm. Subsequently, it heated up to 270 degreeC over about 0.5 hour. After holding at 270 ° C. for 1 hour, it was rapidly cooled to near room temperature.

  As a result of analyzing the obtained contents by gas chromatography and high performance liquid chromatography, the consumption rate of monomer p-DCB was 29.5%, and the production rate of cyclic PAS with respect to the charged monomer (p-DCB) was about It was found that the yield of cyclic PAS was 17.8%, assuming that all sulfur components in the reaction mixture were converted to cyclic PAS.

  Even when a sulfidizing agent different from that in Example 1 was used, the cyclic PAS formation reaction proceeded in a short time, and a larger amount of cyclic PAS than the charged monomer was obtained. This suggests that a part of PPS was converted to cyclic PAS during the reaction, and it was found that cyclic PAS can be obtained with high efficiency in the present invention. However, the production rate was slightly lower than that of Example 1 using sodium hydrosulfide as a preferred sulfiding agent.

[Example 3]
Here, the result of manufacturing cyclic PAS by changing the charging ratio of the raw material linear PAS and the monomer raw material is shown.

  5.18 g of linear PPS-1 (sulfur component amount 0.0480 mol), 1.40 g of a 48 wt% aqueous solution of sodium hydrosulfide (0.673 g (0.0120 mol) of sodium hydrosulfide, 0.730 g of water (0. 0406 mol)), 1.30 g (sodium hydroxide 0.600 g (0.0150 mol), water 0.677 g (0.0376 mol)), p- A cyclic PAS was produced in the same manner as in Example 1 except that DCB was changed to 1.76 g (0.012 mol) and the raw materials were charged.

  As a result of analyzing the obtained contents by gas chromatography and high performance liquid chromatography, the consumption rate of monomer p-DCB was 81.8%, and the production rate of cyclic PAS with respect to the charged monomer (p-DCB) was about It was found that the yield of cyclic PAS was 25.9% assuming that all sulfur components in the reaction mixture were converted to cyclic PAS.

  200 g of the obtained contents were diluted with about 600 g of ion-exchanged water, and then filtered through a glass filter having an average opening of 10 to 16 micrometers. After the filter-on component was dispersed in about 150 g of ion-exchanged water, the mixture was stirred at 70 ° C. for 30 minutes and filtered in the same manner as described above three times to obtain a white solid. This was vacuum dried at 80 ° C. overnight to obtain a dry solid.

  The obtained dry solid was put into a cylindrical filter paper, and Soxhlet extraction was performed for about 5 hours using 150 g of chloroform as a solvent. After removing the solvent from the extract, about 5 g of chloroform was added to prepare a slurry, which was added dropwise to about 500 g of methanol with stirring. The resulting precipitate was collected by filtration and vacuum dried at 70 ° C. for 5 hours to obtain 0.65 g of white powder. This white powder was confirmed to be a compound composed of phenylene sulfide units from an absorption spectrum in infrared spectroscopic analysis. In addition, each color powder is a mixture of cyclic polyphenylene sulfide having 4 to 12 repeating units as the main component based on mass spectral analysis of components separated by high performance liquid chromatography and molecular weight information by MALDI-TOF-MS. The weight fraction of cyclic polyphenylene sulfide was found to be about 92%.

  According to the production method of the cyclic PAS of the present invention, the cyclic PAS formation reaction proceeds in a short time even when the charge ratio of the linear PAS and the monomer raw material is changed, and more cyclic PAS than the charged monomer. Was found to be obtained.

[Comparative Example 1]
Here, the results obtained by using only linear PAS and an organic polar solvent as raw materials and without using a sulfidizing agent and a dihalogenated aromatic compound are shown.

  The raw materials charged in a stainless steel autoclave equipped with a stirrer were only 6.48 g (0.0600 mol sulfur component) of the linear PPS-1 obtained in Reference Example 1 and 615 g (6.21 mol) NMP. Was carried out in the same manner as in Example 1. In addition, the sum total of the sulfur component derived from linear PPS-1 was 0.0600 mol, and the amount of solvent per 1 mol of sulfur components in the reaction mixture was about 10.0 L.

  200 g of the obtained content was fractionated and recovered in the same manner as in Example 3. However, the obtained white powder containing cyclic PPS was very small, about 0.01 g, and almost no reaction. I found out that it was not progressing.

  As is clear from the comparison between Comparative Example 1 and Examples 1 to 3, it was found that almost no cyclic PAS was obtained when a sulfidizing agent and a dihalogenated aromatic compound were not used as raw materials.

[Comparative Example 2]
Here, the results of using only linear PAS, a sulfidizing agent and an organic polar solvent as raw materials and without using a dihalogenated aromatic compound are shown.

  The same operation as in Example 3 was performed except that p-DCB was not charged as a raw material. The content obtained after the reaction was analyzed by high performance liquid chromatography. As a result, it was found that the production rate of cyclic PAS was 3.07% when all sulfur components in the reaction mixture were converted to cyclic PAS. all right. Moreover, in the analysis of high performance liquid chromatography, it was found that a component different from cyclic PPS was the main product, and this component was found to be a linear oligomer component from mass information.

  As is clear from the comparison between Comparative Example 2 and Examples 1 to 3, it was found that almost no cyclic PAS was obtained when no dihalogenated aromatic compound was used as a raw material.

[Example 4]
Here, the result of manufacturing cyclic PAS by changing the linear PAS of the raw material is shown.

  A cyclic PAS was produced in the same manner as in Example 1 except that 6.48 g (0.0600 mol) of the linear PPS-2 obtained in Reference Example 2 was charged as the linear PAS.

  As a result of analyzing the obtained contents by gas chromatography and high performance liquid chromatography, the consumption rate of monomer p-DCB was 66.4%, and the production rate of cyclic PAS with respect to the charged monomer (p-DCB) was about It was found that the yield of cyclic PAS was 21.6%, assuming that all sulfur components in the reaction mixture were converted to cyclic PAS.

  Next, 200 g of the obtained contents were collected and recovered in the same manner as in Example 3. As a result, 0.67 g of white powder containing 90% purity and cyclic PPS was obtained.

  According to the method for producing cyclic PAS of the present invention, the sulfidizing agent and the dihalogenated aromatic compound are heated using 1.25 liters or more of an organic polar solvent with respect to 1 mol of the sulfur component of the sulfidizing agent. Even when using linear PAS obtained by a method of separating cyclic PAS from a PAS mixture containing cyclic PAS and linear PAS obtained by the reaction, cyclic PAS formation reaction proceeds in a short time, Further, it was found that a larger amount of cyclic PAS than that of the charged monomer can be obtained.

[Example 5]
Here, the result of manufacturing the cyclic PAS with the raw material concentration lower than that in Example 1 is shown.

  In a stainless steel autoclave equipped with a stirrer, 3.25 g (0.0301 mol of sulfur component amount) of linear PPS-1 obtained in Reference Example 1 and 0.351 g (sodium hydrosulfide) of a 48 wt% aqueous solution of sodium hydrosulfide 0.168 g (0.00300 mol), water 0.183 g (0.0102 mol)), 0.313 g of a 48 wt% aqueous solution prepared with sodium hydroxide having a purity of 96% (0.144 g (0.00360 mol) of sodium hydroxide) ), 0.169 g (0.00938 mol) of water), 615 g (6.21 mol) of N-methyl-2-pyrrolidone (NMP), 0.453 g (0.00308 mol) of p-dichlorobenzene (p-DCB). . The total amount of sulfur components derived from linear PPS-1 and sodium hydrosulfide was 0.0331 mol, and the amount of solvent per mol of sulfur component in the reaction mixture was about 18.2 L.

  The reaction vessel was sealed under nitrogen gas at room temperature and normal pressure, and then heated from room temperature to 200 ° C. over about 1 hour with stirring at 400 rpm. Subsequently, it heated up to 270 degreeC over about 0.5 hour. After maintaining at 270 ° C. for 2 hours, it was rapidly cooled to near room temperature.

  As a result of analyzing the obtained contents by gas chromatography and high performance liquid chromatography, the consumption rate of monomer p-DCB was 55.8%, and the production rate of cyclic PAS with respect to the charged monomer (p-DCB) was about It was found that the yield of cyclic PAS was 28.8%, assuming 309% and all sulfur components in the reaction mixture were converted to cyclic PAS.

  It was found that cyclic PAS can be obtained with higher yield by reducing the raw material concentration.

[Example 6]
Here, the result of manufacturing the cyclic PAS with the raw material concentration of the charged material higher than that in Example 1 is shown.

  In a stainless steel autoclave equipped with a stirrer, 13.0 g of the linear PPS-1 obtained in Reference Example 1 (sulfur component amount 0.120 mol) and 1.43 g of a 48 wt% aqueous solution of sodium hydrosulfide (sodium hydrosulfide) 0.687 g (0.0122 mol), water 0.713 g (0.0396 mol)), 1.26 g of a 48 wt% aqueous solution prepared using sodium hydroxide with a purity of 96% (sodium hydroxide 0.582 g (0.0146 mol) ), 0.657 g (0.0365 mol) of water), 572 g (5.77 mol) of NMP, and 1.78 g (0.0121 mol) of p-DCB. The total amount of sulfur components derived from linear PPS-1 and sodium hydrosulfide was 0.132 mol, and the amount of solvent per mol of sulfur component in the reaction mixture was about 4.22 L.

  The reaction vessel was sealed under nitrogen gas at room temperature and normal pressure, and then heated from room temperature to 200 ° C. over about 1 hour with stirring at 400 rpm. Subsequently, it heated up to 270 degreeC over about 0.5 hour. After holding at 270 ° C. for 1 hour, it was rapidly cooled to near room temperature.

  As a result of analyzing the obtained contents by gas chromatography and high performance liquid chromatography, the consumption rate of monomer p-DCB was 59.2%, and the production rate of cyclic PAS with respect to the charged monomer (p-DCB) was about It was found that the yield of cyclic PAS was 12.1%, assuming that all sulfur components in the reaction mixture were converted to cyclic PAS.

  It was found that cyclic PAS can be obtained in high yield even under conditions where the raw material concentration is high.

[Example 7]
Here, the raw material concentration of the charged material is made higher than that in Example 1, and the results of the production of cyclic PAS using the linear PPS-2 obtained by the method of Reference Example 2 for the linear PAS of the raw material are shown. .

  In a stainless steel autoclave equipped with a stirrer, 10.4 g of linear PPS-2 obtained by the method of Reference Example 2 (sulfur component amount 0.0960 mol) and 2.81 g of 48% by weight aqueous solution of sodium hydrosulfide (water) Sodium sulfide 1.35 g (0.0240 mol), water 1.46 g (0.0811 mol)), and a 48 wt% aqueous solution prepared with 96% pure sodium hydroxide 2.57 g (sodium hydroxide 1.19 g (0 2.097 mol), 1.33 g (0.0739 mol) of water), 617 g (6.22 mol) of NMP, and 3.53 g (0.0240 mol) of p-DCB. The total amount of sulfur components derived from linear PPS-2 and sodium hydrosulfide was 0.120 mol, and the amount of solvent per mol of sulfur component in the reaction mixture was about 5.02 L.

  The reaction vessel was sealed under nitrogen gas at room temperature and normal pressure, and then heated from room temperature to 200 ° C. over about 1 hour with stirring at 400 rpm. Subsequently, it heated up to 270 degreeC over about 0.5 hour. After holding at 270 ° C. for 1 hour, it was rapidly cooled to near room temperature.

  As a result of analyzing the obtained contents by gas chromatography and high performance liquid chromatography, the consumption rate of monomer p-DCB was 86.6%, and the production rate of cyclic PAS with respect to charged monomer (p-DCB) was about It was found that the yield of cyclic PAS was 19.7%, assuming that all sulfur components in the reaction mixture were converted to cyclic PAS.

  Next, 200 g of the obtained reaction product was collected, and cyclic PPS was recovered in the same manner as in Example 3. As a result, 1.08 g of white powder containing 86% purity of cyclic PPS was obtained.

  It was found that cyclic PAS can be obtained in high yield even under conditions where the raw material concentration is high, and that the yield of cyclic PPS obtained per unit amount of reactant is also high.

[Example 8]
Here, the result of manufacturing cyclic PAS with the raw material concentration of the charged material higher than that in Example 6 is shown.

  In a stainless steel autoclave equipped with a stirrer, 20.7 g of the linear PPS-1 obtained in Reference Example 1 (sulfur component amount 0.192 mol) and 5.61 g of a 48 wt% aqueous solution of sodium hydrosulfide (sodium hydrosulfide) 2.69 g (0.0480 mol), 2.92 g (0.162 mol) of water, and 5.22 g of 48 wt% aqueous solution prepared using 96% pure sodium hydroxide (2.40 g (0.0601 mol) of sodium hydroxide) ), 2.71 g (0.151 mol) of water), 615 g (6.21 mol) of NMP, and 7.06 g (0.0480 mol) of p-DCB. The total amount of sulfur components derived from linear PPS-1 and sodium hydrosulfide was 0.24 mol, and the amount of solvent per mole of sulfur component in the reaction mixture was about 2.50 L.

  The reaction vessel was sealed under nitrogen gas at room temperature and normal pressure, and then heated from room temperature to 200 ° C. over about 1 hour with stirring at 400 rpm. Subsequently, it heated up to 270 degreeC over about 0.5 hour. After holding at 270 ° C. for 1 hour, it was rapidly cooled to near room temperature.

  As a result of analyzing the obtained contents by gas chromatography and high performance liquid chromatography, the consumption rate of monomer p-DCB was 87.2%, and the production rate of cyclic PAS with respect to the charged monomer (p-DCB) was about It was found that the yield of cyclic PAS was 11.2% assuming that all sulfur components in the reaction mixture were converted to cyclic PAS.

  Next, 200 g of the resulting reaction product was collected, and cyclic PPS was recovered in the same manner as in Example 3 to obtain 1.12 g of white powder containing 86% purity and cyclic PPS.

  It was found that cyclic PAS can be obtained in high yield even under conditions where the raw material concentration is high, and that the yield of cyclic PPS obtained per unit amount of reactant is also large.

[Example 9]
Here, the results of manufacturing cyclic PAS with the raw material concentration of the feed made higher than in Example 8 are shown.

  In a stainless steel autoclave equipped with a stirrer, 36.3 g (sulfur component amount 0.336 mol) of linear PPS-1 obtained in Reference Example 1 and 9.82 g (sodium hydrosulfide) of a 48 wt% aqueous solution of sodium hydrosulfide. 4.71 g (0.0840 mol), water 5.11 g (0.284 mol)), and a 48 wt% aqueous solution prepared with 96% pure sodium hydroxide 8.02 g (sodium hydroxide 3.70 g (0.0924 mol)) ), 4.17 g (0.232 mol) of water, 615 g (6.21 mol) of NMP, and 12.3 g (0.0840 mol) of p-DCB. The total amount of sulfur components derived from linear PPS-1 and sodium hydrosulfide was 0.42 mol, and the amount of solvent per mol of sulfur component in the reaction mixture was about 1.43 L.

  The reaction vessel was sealed under nitrogen gas at room temperature and normal pressure, and then heated from room temperature to 200 ° C. over about 1 hour with stirring at 400 rpm. Subsequently, it heated up to 270 degreeC over about 0.5 hour. After holding at 270 ° C. for 1 hour, it was rapidly cooled to near room temperature.

  As a result of analyzing the obtained contents by gas chromatography and high performance liquid chromatography, the consumption rate of monomer p-DCB was 82.3%, and the production rate of cyclic PAS with respect to the charged monomer (p-DCB) was about The yield of cyclic PAS was found to be 5.23%, assuming that 26.2%, all sulfur components in the reaction mixture were converted to cyclic PAS.

  Next, 200 g of the obtained reaction product was collected, and cyclic PPS was recovered in the same manner as in Example 3 to obtain 0.91 g of white powder containing 83% purity and cyclic PPS.

  Although cyclic PAS can be obtained in high yield even under conditions where the raw material concentration of the feed is high, the yield and purity of cyclic PPS obtained per unit amount of the reactant are slightly reduced as compared with the more preferred concentration conditions of the present invention. I understood that

[Example 10]
The same procedure as in Example 8 was carried out except that the temperature was raised from 200 ° C. to 250 ° C. after the raw materials were charged, kept at 250 ° C. for 1 hour, and then rapidly cooled to near room temperature to obtain a reaction product.

  As a result of analyzing the obtained contents by gas chromatography and high performance liquid chromatography, the consumption rate of monomer p-DCB was 87.4%, and the production rate of cyclic PAS with respect to the charged monomer (p-DCB) was about It was found that the yield of cyclic PAS was 10.8%, assuming 52.5% and all sulfur components in the reaction mixture were converted to cyclic PAS.

  Next, 600 g of the obtained reaction product was collected, and cyclic PPS was recovered in the same manner as in Example 3 to obtain 2.8 g of white powder containing 96% purity and containing cyclic PPS. In the recovery of cyclic PPS, the solid component remaining in the cylindrical filter paper after the extraction operation was dried under reduced pressure at 70 ° C. overnight to obtain about 20 g of an off-white solid. As a result of analysis, it was confirmed that this was a linear PPS from an absorption spectrum in infrared spectroscopic analysis.

  Even when the reaction temperature is lowered as compared with Example 8, cyclic PAS can be obtained in high yield, and although the yield of cyclic PPS obtained per unit amount of the reactant is slightly less, a very high purity ring is obtained. The formula PPS was found to be obtained.

[Example 11]
Here, an example is shown in which cyclic PAS is produced using the linear PPS obtained in Example 10 as a raw material.

  In a stainless steel autoclave equipped with a stirrer, 19.4 g of the linear PPS obtained in Example 10 (sulfur component amount 0.180 mol) and 5.26 g of a 48 wt% aqueous solution of sodium hydrosulfide (2. 53 g (0.0450 mol), 2.74 g (0.152 mol) of water, 4.88 g of 48 wt% aqueous solution prepared using sodium hydroxide having a purity of 96% (2.25 g (0.0563 mol) of sodium hydroxide, 2.54 g (0.141 mol) of water), 577 g (5.82 mol) of NMP, and 6.62 g (0.0450 mol) of p-DCB were charged. The total amount of sulfur components derived from the charged linear PPS and sodium hydrosulfide was 0.225 mol, and the amount of solvent per mol of sulfur component in the reaction mixture was about 2.50 L.

  After the raw materials were charged, the contents were obtained in the same manner as in Example 10. As a result of analyzing the obtained contents by gas chromatography and high performance liquid chromatography, the monomer p-DCB consumption rate was 81.1%. The yield of cyclic PAS relative to p-DCB) is about 64.5%, and the yield of cyclic PAS is assumed to be 12.9% assuming that all sulfur components in the reaction mixture are converted to cyclic PAS. I understood.

  Next, 200 g of the resulting reaction product was collected, and cyclic PPS was recovered in the same manner as in Example 3 to obtain 1.02 g of white powder containing 97% purity and containing cyclic PPS.

  From Example 11, a reaction mixture comprising linear PAS, a sulfidizing agent, a dihalogenated aromatic compound and an organic polar solvent was heated and reacted from a PAS mixture containing cyclic PAS and linear PAS. It was found that even when linear PAS obtained by separating formula PAS was used as (a) linear PAS, high-purity cyclic PAS could be obtained in high yield.

[Comparative Example 3]
Here, the results are shown in which the reaction was carried out with the raw material feed concentration being higher than the concentration range of the present invention, that is, with the amount of organic polar solvent used less than 1.25 liters per mole of sulfur component in the reaction mixture.

  In a stainless steel autoclave equipped with a stirrer, 43.2 g (sulfur component amount 0.400 mol) of the linear PPS-1 obtained in Reference Example 1 and 11.7 g (sodium hydrosulfide) of a 48 wt% aqueous solution of sodium hydrosulfide. 5.61 g (0.100 mol), 6.08 g (0.338 mol) of water), 10.4 g of 48 wt% aqueous solution prepared with 96% pure sodium hydroxide (4.800 g (0.120 mol) of sodium hydroxide) ), 5.42 g (0.301 mol) of water, 496 g (5.00 mol) of NMP, and 14.7 g (0.100 mol) of p-DCB. The total amount of sulfur components derived from linear PPS-1 and sodium hydrosulfide was 0.50 mol, and the amount of solvent per mole of sulfur component in the reaction mixture was about 0.97 L.

  The reaction vessel was sealed under nitrogen gas at room temperature and normal pressure, and then heated from room temperature to 200 ° C. over about 1 hour with stirring at 400 rpm. Subsequently, it heated up to 270 degreeC over about 0.5 hour. After holding at 270 ° C. for 1 hour, it was rapidly cooled to near room temperature.

  As a result of analyzing the obtained contents by gas chromatography and high performance liquid chromatography, the consumption rate of monomer p-DCB was 75.5%, and the production rate of cyclic PAS with respect to the charged monomer (p-DCB) was about 13.6%. The cyclic PAS yield was 2.72%, assuming that all sulfur components in the reaction mixture were converted to cyclic PAS.

  It was found that when the raw material feed concentration was higher than the concentration range of the present invention, most of the product was a polymer (linear PPS), and cyclic PAS was hardly obtained.

[Reference Example 4]
Here, the reaction mixture obtained by heating and reacting the sulfidizing agent and the dihalogenated aromatic compound with an organic polar solvent of 1.25 liters or more per mole of the sulfur component of the sulfidizing agent is solid-liquid. An example is shown in which cyclic PAS and linear PAS are separated by being subjected to separation, and linear PAS is produced as a solid containing a solvent.

  A stainless steel autoclave equipped with a stirrer was charged with 46.75 g (0.40 mol) of a 48 wt% aqueous solution of sodium hydrosulfide and 36.46 g (0.42 mol) of a 48 wt% aqueous solution prepared using 96% sodium hydroxide. ), NMP 1000 g (10.1 mol), and p-DCB 59.98 g (0.41 mol) were charged. After sufficiently replacing the inside of the reaction vessel with nitrogen, the pressure was increased to 0.3 MPa with pressurized nitrogen using a pressurized nitrogen and sealed.

  While stirring at 400 rpm, the temperature was raised from room temperature to 200 ° C. over about 1 hour. At this stage, the pressure in the reaction vessel was 0.9 MPa as a gauge pressure. Next, the temperature was raised from 200 ° C. to 250 ° C. over about 30 minutes. The pressure in the reaction vessel at this stage was 1.5 MPa as a gauge pressure. After maintaining at 250 ° C. for 2 hours, the contents were recovered after quenching to near room temperature.

  As a result of analyzing the obtained contents by gas chromatography and high performance liquid chromatography, it was found that the consumption rate of monomer p-DCB was 92%, and that the sulfur component in the reaction mixture was all converted to cyclic PPS. The formula PPS production rate was found to be 16.7%.

  The contents obtained above, that is, a reaction mixture containing at least cyclic PAS, linear PAS, NMP, and NaCl as a by-product salt was charged into an eggplant flask. Heated to ° C. The temperature of the filter part of the pressure filter set with a glass filter having an average aperture of 10 micrometers was adjusted to 100 ° C., and the reaction mixture was subjected to solid-liquid separation by hot pressure filtration using pressurized nitrogen. . By this operation, a wet solid was obtained.

  A portion of the wet solid obtained was collected, washed thoroughly with warm water and then dried to obtain a dry solid. As a result of the analysis of the dried solid, it was found from the absorption spectrum in infrared spectroscopic analysis that it was a linear polyphenylene sulfide and the weight average molecular weight was 11,000. Moreover, it turned out that the linear PPS content rate of the solid content of a wet state is about 22% from the weight of the obtained dry solid. Hereinafter, the wet solid content containing the linear PPS obtained here is referred to as linear PPS-3. As a result of analyzing the wet solid, the NMP and NaCl contents were about 47% and about 31%, respectively.

[Example 12]
Here, an example is shown in which cyclic PAS is produced using the wet-state linear PPS (linear PPS-3) obtained in Reference Example 4 as a raw material.

  94.26 g of wet linear PPS (linear PPS-3) obtained by the method shown in Reference Example 4 in a stainless steel autoclave equipped with a stirrer (20.7 g of linear PPS and 44. NMP). 3 g, 0.192 mol on a sulfur component basis), 5.61 g of a 48 wt% aqueous solution of sodium hydrosulfide (2.69 g (0.0480 mol) of sodium hydrosulfide, 2.92 g (0.162 mol) of water), purity 48% by weight aqueous solution prepared with 96% sodium hydroxide 5.21 g (sodium hydroxide 2.40 g (0.0600 mol), water 2.71 g (0.150 mol)), NMP 571 g (5.76 mol) , And 7.41 g (0.0504 mol) of p-DCB were charged. The sum of the sulfur components derived from linear PPS-3 and sodium hydrosulfide was 0.24 mol, and the amount of solvent per mole of sulfur component in the reaction mixture was about 2.5 L.

  The reaction vessel was sealed under nitrogen gas at room temperature and normal pressure, and then heated from room temperature to 200 ° C. over about 1 hour with stirring at 400 rpm. Next, the temperature was raised to 260 ° C. over about 0.5 hours. After maintaining at 260 ° C. for 30 minutes, it was rapidly cooled to near room temperature.

  As a result of analyzing the obtained contents by gas chromatography and high performance liquid chromatography, the consumption rate of monomer p-DCB was 86.6%, and the production rate of cyclic PAS with respect to charged monomer (p-DCB) was about It was found that the yield of cyclic PAS was 12.9% when 61.4%, assuming that all sulfur components in the reaction mixture were converted to cyclic PAS.

  Next, 200 g of the resulting reaction product was collected, and cyclic PPS was recovered in the same manner as in Example 3 to obtain 1.24 g of white powder containing 96% purity and containing cyclic PPS.

  It was found that a highly severe cyclic PAS can be obtained in a high yield even when a wet linear PPS containing a solvent is used as a raw material for charging.

[Example 13]
Here, after the reaction was carried out by the method of Reference Example 12, the obtained reaction mixture was subjected to solid-liquid separation by the same method as in Reference Example 4, and the wet linear PAS obtained by this solid-liquid separation was used as a raw material. The example which manufactured manufacture of cyclic PAS is shown.

  Reaction was carried out in the same manner as in Example 12 using wet linear PPS (linear PPS-3) obtained by the method shown in Reference Example 4 as a raw material to obtain a reaction mixture.

  The obtained reaction mixture was subjected to solid-liquid separation using a pressure filter in the same manner as in Reference Example 4 to obtain a wet solid content. Hereinafter, the wet solid content containing the linear PPS obtained here is referred to as linear PPS-4. A portion of the wet solid obtained was collected, washed thoroughly with warm water and then dried to obtain a dry solid. As a result of analysis of this dry solid, it was found from the absorption spectrum in infrared spectroscopic analysis that it was a linear polyphenylene sulfide and the weight average molecular weight was 11,500. Moreover, it turned out that the linear PPS content rate of the solid content of a wet state is about 22% from the weight of the obtained dry solid. As a result of analysis of the solid content in the wet state, the NMP and NaCl contents were about 43% and about 35%, respectively.

  A stainless steel autoclave equipped with a stirrer contains 59.3 g of the wet linear PPS (linear PPS-4) obtained above (13.0 g of linear PPS and 25.3 g of NMP). 0.120 mol), 3.51 g of 48% by weight aqueous solution of sodium hydrosulfide (1.68 g (0.0300 mol) of sodium hydrosulfide, 1.82 g (0.101 mol) of water), 96% pure sodium hydroxide 2.73 g (1.26 g (0.0315 mol) of sodium hydroxide, 1.42 g (0.0789 mol) of water), 360 g (3.63 mol) of NMP, and p-DCB4. 63 g (0.0315 mol) was charged. The total amount of sulfur components derived from linear PPS-4 and sodium hydrosulfide was 0.15 mol, and the amount of solvent per mol of sulfur component in the reaction mixture was about 2.5 L.

  The reaction vessel was sealed under nitrogen gas at room temperature and normal pressure, and then heated from room temperature to 200 ° C. over about 1 hour with stirring at 400 rpm. Next, the temperature was raised to 260 ° C. over about 0.5 hours. After maintaining at 260 ° C. for 30 minutes, it was rapidly cooled to near room temperature.

  As a result of analyzing the obtained contents by gas chromatography and high performance liquid chromatography, the consumption rate of monomer p-DCB was 86.2%, and the production rate of cyclic PAS relative to the charged monomer (p-DCB) was about It was found that the yield of cyclic PAS was 13.1%, assuming 62.5% and all sulfur components in the reaction mixture were converted to cyclic PAS.

  Next, 200 g of the obtained reaction product was collected, and cyclic PPS was recovered in the same manner as in Example 3 to obtain 1.27 g of white powder containing 96% purity and containing cyclic PPS.

  From Examples 12 and 13, a wet linear PAS obtained by separating a reaction product obtained using a wet state linear PAS, a sulfidizing agent, a dihalogenated aromatic compound, and an organic polar solvent as raw materials ( a) It was found that cyclic PAS with high purity can be obtained in a high yield even when used as linear PAS.

Claims (10)

At least (a) linear polyarylene sulfide,
(B) a sulfidizing agent,
(C) a dihalogenated aromatic compound, and (d) an organic polar solvent,
Is a method of producing a cyclic polyarylene sulfide by heating and reacting a reaction mixture containing 1.25 liters or more of an organic polar solvent with respect to 1 mol of a sulfur component in the reaction mixture. A process for producing a cyclic polyarylene sulfide. The method for producing a cyclic polyarylene sulfide according to claim 1, wherein the heating temperature is a temperature exceeding the reflux temperature at normal pressure of the reaction mixture. The method for producing a cyclic polyarylene sulfide according to claim 1 or 2, wherein the amount of the organic solvent used is 50 liters or less with respect to 1 mol of the sulfur component in the reaction mixture. The method for producing a cyclic polyarylene sulfide according to any one of claims 1 to 3, wherein the pressure when heating the reaction mixture is 0.05 MPa or more in terms of gauge pressure. The method for producing a cyclic polyarylene sulfide according to any one of claims 1 to 4, wherein the dihalogenated aromatic compound (c) is dichlorobenzene. 6. The method for producing a cyclic polyarylene sulfide according to claim 1, wherein the sulfidizing agent (b) is an alkali metal sulfide. The polyarylene sulfide obtained by bringing the sulfidizing agent and the dihalogenated aromatic compound into contact with each other in an organic polar solvent is used as the linear polyarylene sulfide (a). A process for producing the cyclic polyarylene sulfide according to claim 1. A cyclic polyarylene sulfide obtained by heating and reacting a sulfidizing agent and a dihalogenated aromatic compound with an organic polar solvent of 1.25 liters or more per mole of the sulfur component of the sulfidizing agent; The linear polyarylene sulfide obtained by separating the cyclic polyarylene sulfide from the polyarylene sulfide mixture containing the linear polyarylene sulfide is used as the linear polyarylene sulfide (a). To 6. The method for producing a cyclic polyarylene sulfide according to any one of items 1 to 6. At least a reaction mixture composed of linear polyarylene sulfide, a sulfidizing agent, a dihalogenated aromatic compound, and an organic polar solvent is heated using 1.25 liters or more of an organic polar solvent with respect to 1 mol of a sulfur component in the reaction mixture. The linear polyarylene sulfide obtained by separating the cyclic polyarylene sulfide from the polyarylene sulfide mixture containing the cyclic polyarylene sulfide and the linear polyarylene sulfide obtained by the reaction is converted into the linear polyarylene. It uses as a sulfide (a), The cyclic polyarylene sulfide manufacturing method in any one of Claim 1 to 6 characterized by the above-mentioned. The method for producing a cyclic polyarylene sulfide according to any one of claims 1 to 9, wherein the linear polyarylene sulfide (a) has a weight average molecular weight of 2,500 or more.