JP2020007490A - Method for producing carboxyalkylamino group-containing compound, and method for producing cyclic polyarylene sulfide - Google Patents

Abstract

To provide a method for producing by separating in high purity an oligomer of a carboxyalkylamino group-containing compound, and a cyclic polyarylene sulfide from a reaction mixture obtained by a production process of a polyarylene sulfide.SOLUTION: The method for producing an oligomer of a carboxyalkylamino group-containing organic compound or cyclic polyarylene sulfide includes the steps of: purifying a reaction mixture obtained by reacting a dihaloaromatic compound with alkali metal sulfide, or alkalimetal hydrosulfide and alkali metal hydroxide in an organic polar solvent; contacting the reaction mixture containing oligoarylene sulfide, and a carboxyalkylamino group-containing compound with water at higher than 100°C and pH 6 or higher to separate the carboxyalkylamino group-containing compound (n=0), and oligoarylene sulfide; and thereafter subjecting obtained oligoarylene sulfide to solid-liquid separation with the organic polar solvent.SELECTED DRAWING: Figure 1

Description

  Method for producing cyclic polyarylene sulfide or carboxyalkylamino group-containing compound by efficiently separating cyclic polyarylene sulfide and carboxyalkylamino group-containing compound contained in the reaction mixture obtained in the production process of polyarylene sulfide resin About.

  Polyarylene sulfide resin represented by polyphenylene sulfide resin is excellent in heat resistance, chemical resistance and the like, and is widely used in electric and electronic parts, automobile parts, water heater parts, fibers, film applications, and the like. Particularly, in applications such as packing for lithium ion batteries and gasket members, in recent years, particularly high molecular weight PAS resins have been widely used because of their excellent toughness and moldability.

  As such a high molecular weight polyarylene sulfide resin, a dihalo aromatic compound, an alkali metal hydrosulfide and an organic acid alkali metal salt in the presence of a solid alkali metal sulfide and an aprotic polar organic solvent are used to remove water in the reaction system. There is known a linear high molecular weight polyarylene sulfide resin obtained by performing a reaction while keeping the amount and the amount of an organic acid alkali metal salt used low (see Patent Document 1).

  However, the linear high-molecular-weight polyarylene sulfide resin has high toughness and excellent mechanical strength, but has a low melt viscosity in a low shear region and a low crystallization rate, so that the resin cannot be used in a mold parting line. There was a property that it easily entered and burrs were easily generated. For this reason, although the melt viscosity in the low shear region was increased by incorporating a crosslinked structure into the resin skeleton, and the flow behavior of the PAS resin was attempted to be improved, the resin was easily gelled during thermal oxidative crosslinking of the linear high molecular weight PAS resin. In addition, there are problems that the melt stability is poor and that the obtained cross-linked polyarylene sulfide resin has a higher viscosity and the crystallization speed during molding and solidification is further reduced.

  Then, the present inventors, when performing thermal oxidative crosslinking using a linear high molecular weight PAS resin, use a carboxyalkylamino group-containing compound (1a) represented by the following structural formula (1)

(In the formula, Ar is an aryl group having a halogen atom, R ¹ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms or a cyclohexyl group, and R ² represents an alkylene group having 3 to 5 carbon atoms. X represents a hydrogen atom or an alkali metal atom. Also, -NR ¹ R ² COOX group is sometimes referred to as carboxyalkylamino group) as an additive to suppress the increase in viscosity during melting and to melt the resin. It has been clarified that a crosslinked polyarylene sulfide resin having a high crystallization rate at the time of molding and solidifying and a method for producing the same can be provided while improving the stability (see Patent Document 2).

  On the other hand, cyclic polyarylene sulfide can be applied to highly functional materials and functional materials based on cyclic materials, such as the utilization as a monomer for the synthesis of high molecular weight linear compounds by ring-opening polymerization. Attention has been focused on the nature (Patent Document 3).

  However, since the compound (1a) and the cyclic polyarylene sulfide (2) are formed together in the production process of the polyarylene sulfide resin, a method for efficiently separating them has been required.

International Publication 2010/058713 pamphlet JP 2013-159656 A JP 2009-149864 A JP 2013-245191 A

  For this reason, the present inventors contacted an organic polar solvent and washed the reaction mixture obtained after the polymerization reaction of the polyarylene sulfide resin, followed by solid-liquid separation. By contacting with water at a pH of 6 or more, it has been found that a compound (1a) represented by the following structural formula (1a) and a cyclic polyarylene sulfide can be efficiently separated with higher purity.

  Further, after that, the product containing the obtained cyclic polyarylene sulfide was examined in more detail, and it was found that the product contained the following structural formula (1b)

(In the formula (1b), Ar is an aryl group having a halogen atom, Ar ′ is an arylene group, R ¹ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms or a cyclohexyl group, and R ² represents X represents an alkylene group having 3 to 5 carbon atoms, X represents a hydrogen atom or an alkali metal atom, and in the formula (1b), n = 1 to 40). It has been found that there is still room for improvement in the purification of the formula polyarylene sulfide. Further, the compound (1b) suppresses the increase in viscosity at the time of melting to improve the melt stability of the resin as compared with the compound (1a) represented by the structural formula (1a), and also has a crystal at the time of molding and solidifying. In terms of providing a cross-linked polyarylene sulfide resin having a high conversion rate and a method for producing the same, it has been clarified that the gas generated during melt molding can be suppressed while being similar.

  The problem to be solved by the present invention is to separate a cyclic polyarylene sulfide and a compound (1b) represented by the structural formula (1b) from a reaction mixture obtained after the polymerization reaction of the polyarylene sulfide resin. It is another object of the present invention to provide a method and a method for producing each of them with higher purity.

  As a result of various studies by the present inventors, the reaction mixture obtained after the polymerization reaction of the polyarylene sulfide resin is subjected to a solvent washing step and a step of contacting with water at a temperature higher than 100 ° C. and at a pH of 6 or more. Thus, the compound (1) represented by the following structural formula (1) is efficiently separated from the oligoarylene sulfide (2), whereby the oligoarylene sulfide is obtained from the reaction mixture obtained in the production process of the polyarylene sulfide resin. It has been found that can be efficiently produced with high purity, and that a carboxyalkylamino group-containing compound can be efficiently produced with high purity, and the present invention has been completed.

That is, the present invention provides a reaction between a dihaloaromatic compound and (i) an alkali metal sulfide or (ii) an alkali metal hydrosulfide and an alkali metal hydroxide in an organic polar solvent (3). The compound (1) represented by the following structural formula (1), a cyclic polyarylene sulfide (2), an organic polar solvent (3), a polyarylene sulfide resin (4) and an alkali metal halide (5) Step (1a) of obtaining a crude reaction mixture containing the compound (1a), the crude reaction mixture is subjected to solid-liquid separation, and at least the polyarylene sulfide resin (4) and the alkali metal halide (5) are separated and removed. (1) having a step (1b) of obtaining a reaction mixture (L1) containing a cyclic polyarylene sulfide (2) and the organic polar solvent,
A step (2) of solid-liquid separating the organic polar solvent from the reaction mixture (L1) to obtain a reaction mixture (S2) containing the compound (1) and the cyclic polyarylene sulfide (2);
The compound (1a) represented by the structural formula (1a) is separated and removed by bringing the reaction mixture (S2) into contact with water at a temperature higher than 100 ° C. and at a pH of 6 or more. (3) obtaining a reaction mixture (S3) containing the compound (1b) and the cyclic polyarylene sulfide (2)
(4) separating the compound (1b) and the cyclic polyarylene sulfide (2) by contacting the reaction mixture (S3) with an organic polar solvent (7);
A method for producing a compound (1b) represented by the following structural formula (1b), comprising:

(In the formulas (1), (1a) and (1b), Ar is an aryl group having a halogen atom, Ar ′ is an arylene group, R ¹ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms or Represents a cyclohexyl group, R ² represents an alkylene group having 3 to 5 carbon atoms, X represents a hydrogen atom or an alkali metal atom, In formula (1), n = 0 to 40, and in formula (1b), n = 1 to 40).

The present invention also provides a reaction between a dihaloaromatic compound and (i) an alkali metal sulfide or (ii) an alkali metal hydrosulfide and an alkali metal hydroxide in an organic polar solvent (3). The compound (1) represented by the following structural formula (1), a cyclic polyarylene sulfide (2), an organic polar solvent (3), a polyarylene sulfide resin (4) and an alkali metal halide (5) Step (1a) of obtaining a crude reaction mixture containing the compound (1a), the crude reaction mixture is subjected to solid-liquid separation, and at least the polyarylene sulfide resin (4) and the alkali metal halide (5) are separated and removed. (1) having a step (1b) of obtaining a reaction mixture (L1) containing a cyclic polyarylene sulfide (2) and the organic polar solvent,
A step (2) of solid-liquid separating the organic polar solvent from the reaction mixture (L1) to obtain a reaction mixture (S2) containing the compound (1) and the cyclic polyarylene sulfide (2);
The compound (1a) represented by the structural formula (1a) is separated and removed by bringing the reaction mixture (S2) into contact with water at a temperature higher than 100 ° C. and at a pH of 6 or more. (3) obtaining a reaction mixture (S3) containing the compound (1b) and the cyclic polyarylene sulfide (2)
(4) separating the compound (1b) and the cyclic polyarylene sulfide (2) by contacting the reaction mixture (S3) with an organic polar solvent (7);
Method for producing cyclic polyarylene sulfide (2), characterized by having

(In the formulas (1), (1a) and (1b), Ar is an aryl group having a halogen atom, Ar ′ is an arylene group, R ¹ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms or Represents a cyclohexyl group, R ² represents an alkylene group having 3 to 5 carbon atoms, X represents a hydrogen atom or an alkali metal atom, In Formula (1), n = 0 to 40, and in Formula (1a), n = 1 to 40).

Further, the present invention provides a reaction between a dihalo aromatic compound and (i) an alkali metal sulfide or (ii) an alkali metal hydrosulfide and an alkali metal hydroxide in an organic polar solvent (3). And a compound (1) represented by the following structural formula (1), a cyclic polyarylene sulfide (2), an organic polar solvent (3), a polyarylene sulfide resin (4), and an alkali metal halide (5). Step (1a) of obtaining a crude reaction mixture, solid-liquid separation of the crude reaction mixture, separation and removal of at least the polyarylene sulfide resin (4) and the alkali metal halide (5), and at least the compound (1); A step (1) having a step (1b) of obtaining a reaction mixture (L1) containing the cyclic polyarylene sulfide (2) and the organic polar solvent,
A step (2) of solid-liquid separating the organic polar solvent from the reaction mixture (L1) to obtain a reaction mixture (S2) containing the compound (1) and the cyclic polyarylene sulfide (2);
The compound (1a) represented by the structural formula (1a) is separated and removed by bringing the reaction mixture (S2) into contact with water at a temperature higher than 100 ° C. and at a pH of 6 or more. (3) obtaining a reaction mixture (S3) containing the compound (1b) and the cyclic polyarylene sulfide (2)
(4) separating the compound (1b) and the cyclic polyarylene sulfide (2) by contacting the reaction mixture (S3) with an organic polar solvent (7);
Characterized by having
Method for separating cyclic polyarylene sulfide (2) from compound (1b)

(In the formulas (1), (1a) and (1b), Ar is an aryl group having a halogen atom, Ar ′ is an arylene group, R ¹ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms or Represents a cyclohexyl group, R ² represents an alkylene group having 3 to 5 carbon atoms, X represents a hydrogen atom or an alkali metal atom, In formula (1), n = 0 to 40, and in formula (1b), n = 1 to 40).

  According to the present invention, a method for separating a cyclic polyarylene sulfide and the compound (1b) represented by the structural formula (1b) from a reaction mixture obtained after the polymerization reaction of the polyarylene sulfide resin, It is possible to provide a method for producing each of them with high purity.

It is a high temperature GPC measurement chart of the component contained in the filtration residue (5) in a process (5) in an example. The vertical axis represents the value obtained by differentiating the concentration fraction by the logarithmic value of the molecular weight, and the horizontal axis represents the molecular weight. FIG. 4 is a FD-MASS measurement chart of components contained in a solid (6) in a step (6) in Examples. The vertical axis represents intensity and the horizontal axis represents mass-to-charge ratio (m / z).

  The present invention comprises reacting a dihaloaromatic compound with (i) an alkali metal sulfide or (ii) an alkali metal hydrosulfide and an alkali metal hydroxide in an organic polar solvent (3). A crude compound containing a compound (1) represented by the following structural formula (1), a cyclic polyarylene sulfide (2), an organic polar solvent (3), a polyarylene sulfide resin (4), and an alkali metal halide (5). Step (1a) of obtaining a reaction mixture, the crude reaction mixture is subjected to solid-liquid separation to separate and remove at least the polyarylene sulfide resin (4) and the alkali metal halide (5). (1) having a step (1b) of obtaining a reaction mixture (L1) containing the formula polyarylene sulfide (2) and the organic polar solvent.

  Further, in the step (1), a dihaloaromatic compound and (i) an alkali metal sulfide or (ii) an alkali metal hydrosulfide and an alkali metal hydroxide are mixed in an organic polar solvent (3). After the reaction, the compound (1) represented by the following structural formula (1), a cyclic polyarylene sulfide (2), an organic polar solvent (3), a polyarylene sulfide resin (4) and an alkali metal halide (5) (A) obtaining a crude reaction mixture containing

  The dihalo aromatic compound used in the present invention is, for example, a halogenated aromatic compound having two halogen atoms directly bonded to an aromatic ring, and specifically, p-dichlorobenzene, o-dichlorobenzene M-dichlorobenzene, dibromobenzene, diiodobenzene, tribromobenzene, dibromonaphthalene, triiodobenzene, dichlorodiphenylbenzene, dibromodiphenylbenzene, dichlorobenzophenone, dibromobenzophenone, dichlorodiphenylether, dichlorobenzene Examples thereof include dihaloaromatic compounds such as bromodiphenyl ether, dichlorodiphenyl sulfide, dibromodiphenyl sulfide, dichlorbiphenyl, and dibromobiphenyl, and mixtures thereof, and these compounds may be subjected to block copolymerization. Of these, preferred are dihalogenated benzenes, and particularly preferred are those containing 80 mol% or more of p-dichlorobenzene.

  For the purpose of increasing the viscosity of the polyarylene sulfide resin by forming a branched structure, a polyhalo aromatic compound having three or more halogen substituents in one molecule may be used as a branching agent, if desired. . Examples of such polyhalo aromatic compounds include 1,2,4-trichlorobenzene, 1,3,5-trichlorobenzene, 1,4,6-trichloronaphthalene, tetrachlorobenzene and the like.

  Further, a polyhalo aromatic compound having a functional group having active hydrogen such as an amino group, a thiol group, or a hydroxyl group may be used in combination. Examples of such polyhalo aromatic compounds include dihaloanilines such as 2,6-dichloroaniline, 2,5-dichloroaniline, 2,4-dichloroaniline, and 2,3-dichloroaniline; Trihaloanilines such as 3,4-trichloroaniline, 2,3,5-trichloroaniline, 2,4,6-trichloroaniline and 3,4,5-trichloroaniline; 2,2′-diamino-4,4 ′ Dihaloaminodiphenyl ethers such as -dichlorodiphenyl ether and 2,4'-diamino-2 ', 4-dichlorodiphenyl ether, and compounds in which an amino group in a mixture thereof is replaced with a thiol group or a hydroxyl group. . Further, in these active hydrogen-containing polyhalo aromatic compounds, a hydrogen atom bonded to a carbon atom forming an aromatic ring is replaced with another inert group, for example, an active hydrogen-containing polyhalo group such as an alkyl group. Aromatic compounds can also be used. Among these various active hydrogen-containing polyhalo aromatic compounds, preferred are active hydrogen-containing dihalo aromatic compounds, and particularly preferred is dichloroaniline.

  Further, a polyhalo aromatic compound having a nitro group may be used in combination. Examples of the polyhaloaromatic compound having a nitro group include mono- or dihalonitrobenzenes such as 2,4-dinitrochlorobenzene and 2,5-dichloronitrobenzene; 2-nitro-4,4'-dichlorodiphenyl ether; Dihalonitrodiphenylethers; dihalonitrodiphenylsulfones such as 3,3'-dinitro-4,4'-dichlorodiphenylsulfone; 2,5-dichloro-3-nitropyridine, 2-chloro-3,5 Mono- or dihalonitropyridines such as dinitropyridine; or various dihalonitronaphthalenes.

  A polyhaloaromatic compound having three or more halogen substituents in one molecule, a polyhaloaromatic compound having a functional group having active hydrogen and a polyhaloaromatic compound having a nitro group (hereinafter collectively referred to as “polyhaloaromatic compound”) ) Is an optional component with respect to the dihalo aromatic compound as an essential component, but when used in combination, the total amount of the polyhalo aromatic compound is 0 with respect to the total amount of the dihalo aromatic compound. 0.001 mol% or more, more preferably 0.01 mol%, and more preferably 3% or less, more preferably 1% or less. preferable. The main chain tends to branch according to the proportion of the polyhalo aromatic compound.

  The alkali metal sulfide used in the present invention includes lithium sulfide, sodium sulfide, rubidium sulfide, cesium sulfide and a mixture thereof. Such alkali metal sulfides can be used as hydrates, aqueous mixtures or anhydrides. Further, the alkali metal sulfide can be derived by a reaction between the alkali metal hydrosulfide and the alkali metal hydroxide.

  Usually, a small amount of an alkali metal hydroxide may be added in order to react with a small amount of an alkali metal hydrosulfide or an alkali metal thiosulfate in the alkali metal sulfide.

  Examples of the organic polar solvent (3) used in the present invention include formamide, acetamide, N-methylformamide, N, N-dimethylacetamide, tetramethylurea, N-methyl-2-pyrrolidone, 2-pyrrolidone, and N-methyl-ε. Amides such as caprolactam, ε-caprolactam, hexamethylphosphoramide, N-dimethylpropylene urea, 1,3-dimethyl-2-imidazolidinonic acid, urea and lactams; sulfolane such as sulfolane and dimethyl sulfolane; Examples thereof include nitriles such as nitriles; ketones such as methylphenyl ketone and mixtures thereof. Among them, N-methyl-2-pyrrolidone, 2-pyrrolidone, N-methyl-ε-caprolactam, ε-caprolactam, Hexamethylphosphoramide, N-dimethyl Pyrene urea, amide with 1,3-dimethyl-2-imidazolidinone aliphatic cyclic structure is preferred.

  In the polymerization reaction of the polyarylene sulfide resin, the above-mentioned alkali metal sulfide or alkali metal hydrosulfide and alkali metal hydroxide, which is called a sulfidizing agent, and dihalo-aromatic in the presence of these organic polar solvents (3) React with the compound. The polymerization conditions should generally range from 200 to 330 ° C. and the pressure should be such that the dihaloaromatic compound, which is the polymerization solvent and the polymerization monomer, is substantially kept in a liquid phase. It is selected from the range of 1 to 20 MPa, preferably the range of 0.1 to 2 MPa.

  As one specific embodiment of the method for producing the polyarylene sulfide resin used in the present invention, 1) for example, an alkali metal sulfide or a hydrated alkali metal hydrosulfide and an alkali metal hydroxide in the presence of a dihalo aromatic compound A amide, urea or lactam having an alicyclic structure to produce a slurry containing a solid alkali metal sulfide by dehydrating the product, and then producing a slurry containing a solid alkali metal sulfide, and then further adding a polarizer such as NMP. A step of adding an organic solvent, dehydrating by removing water, and then, in the slurry obtained through the dehydration step, having a dihalo-aromatic compound, an alkali metal hydrosulfide, and the aliphatic cyclic structure An alkali metal salt of a hydrolyzate of an amide, urea or lactam is combined with a polar organic solvent such as NMP in an amount of 0.02 mol per mole of a polar organic solvent. Method for producing a polyarylene sulfide resin having a step of performing the polymerization by reacting the following as essential production steps and the like.

In the presence of an amide group-containing cyclic hydrocarbon compound, as another specific method of polymerizing an alkali metal sulfide or an alkali metal hydrosulfide and an aromatic dihalogen compound,
2) a method using a polymerization aid such as an alkali metal carboxylate or lithium halide;
3) a method using a crosslinking agent such as an aromatic dihalogen compound,
4) a method in which a polymerization reaction is carried out in the presence of a small amount of water and then water is added to carry out further polymerization;
5) During the reaction between the alkali metal sulfide and the aromatic dihalogen compound, a method in which the gas phase of the reaction vessel is cooled to condense a part of the gas phase in the reaction vessel and reflux the liquid phase. .
Among them, the method 1) is particularly preferable because the production of by-products is small and a linear, high-molecular-weight polyarylene sulfide resin can be easily obtained at low cost.

Thus, in the organic polar solvent (3), the dihalo-aromatic compound is polymerized with (i) the alkali metal sulfide or (ii) the alkali metal hydrosulfide and the alkali metal hydroxide. As a result, a polyarylene sulfide resin (4) is obtained as a product. In addition, the compound (1) and the cyclic polyarylene sulfide (2) are also generated.
The polyarylene sulfide resin (4) to be produced has a resin structure having a repeating unit of a structure in which an aromatic ring and a sulfur atom are bonded, and specifically has the following general formula (3)

However, in the formula (3), Ar ′ is an arylene group. n ranges from more than 40, preferably from 41 or more to 500 or less. ). The terminal is not particularly limited, but may be a group having a carboxy group such as a functional group having an active hydrogen and an alkali metal salt thereof, a halogen atom, or a carboxyalkylamino group in addition to the aryl group derived from the raw material. .

  The polyarylene sulfide resin (4) used in the present invention does not include the compound (1) including the compound (1a) or the compound (1b) and the cyclic polyarylene sulfide (2).

  In the present invention, a dihalo aromatic compound is reacted with an alkali metal sulfide in the presence of the compound (1b) or the cyclic polyarylene sulfide (2) obtained by the production method of the present invention, to thereby form the compound (1). ), A cyclic polyarylene sulfide (2), an organic polar solvent (3), a polyarylene sulfide resin (4) and an alkali metal halide (5) to obtain a crude reaction mixture, or by the production method of the present invention. In the presence of the obtained compound (1b) or cyclic polyarylene sulfide (2), a dihaloaromatic compound is reacted with an alkali metal sulfide to cause the compound (1), cyclic polyarylene sulfide (2), A mode for obtaining a crude reaction mixture containing an organic polar solvent (3), a polyarylene sulfide resin (4) and an alkali metal halide (5) is also included. .

  In the production of the polyarylene sulfide resin, for example, when the organic polar solvent is N-methyl-2-pyrrolidone and the dihalo aromatic compound is p-dichlorobenzene as the raw material for producing the polyarylene sulfide resin, the compound ( As 1a), the following general formula (1a ′)

(Wherein X represents an alkali metal atom or a hydrogen atom) (this compound may be abbreviated as “CP-MABA”).

  Subsequently, in the step (1), the crude reaction mixture is subjected to solid-liquid separation to separate and remove at least the polyarylene sulfide resin (4) and the alkali metal halide (5). A step (1b) of obtaining a reaction mixture (L1) containing the formula polyarylene sulfide (2) and the organic polar solvent.

  The polyarylene sulfide resin (4) and the alkali metal halide (5) are separated and removed from the crude reaction mixture, and the reaction mixture containing the compound (1), the cyclic polyarylene sulfide (2) and the organic polar solvent ( The method for obtaining L1) is not particularly limited. For example, at least the polyarylene sulfide resin (4) and the alkali metal halide (5) are separated and removed from the crude reaction mixture by a solid-liquid separation operation by filtration. A method for obtaining a reaction mixture (L1) containing the compound (1), the cyclic polyarylene sulfide (2) and the organic polar solvent is mentioned. At that time, if necessary, the method may include a step (1c) of removing a part or most of the organic polar solvent in the crude reaction mixture by a solid-liquid separation operation by distillation, and the step (1c) , The crude reaction mixture may be subjected to a solid-liquid separation operation by filtration. When performing the solid-liquid separation operation by filtration of the crude reaction mixture, the crude reaction mixture obtained in the step (1a) or, preferably, after the solid-liquid separation in the steps (1b) to (1c), The obtained solid content (slurry) is mixed with an organic polar solvent (6), and washed by contacting at 10 to 200 ° C, preferably 50 to 150 ° C, more preferably 80 to 130 ° C. Step (1d) may be included, and after this step, a solid component containing the polyarylene sulfide resin (4) and the alkali metal halide (5) is removed by a solid-liquid separation operation by filtration to obtain the compound ( The filtrate component containing 1), the cyclic polyarylene sulfide (2) and the organic polar solvent ((3) and (6)) can also be obtained as a reaction mixture (L1).

  In the step (1d), the pressure at which the organic polar solvent (6) is brought into contact with the crude reaction mixture or the solid content (slurry) may be normal pressure or pressure. It is preferable to perform the treatment under a pressure in the range of 0.5 to [MPa]. As the organic polar solvent (6) to be used, those which do not substantially cause an undesired side reaction such as decomposition or crosslinking of the polyarylene sulfide resin (4) are preferable. For example, formamide, acetamide, N-methylformamide, N, N-dimethyl Acetamide, tetramethylurea, N-methyl-2-pyrrolidone, 2-pyrrolidone, N-methyl-ε-caprolactam, ε-caprolactam, hexamethylphosphoramide, N-dimethylpropyleneurea, 1,3-dimethyl-2- Amides, ureas and lactams such as imidazolidinonic acid; sulfolane such as sulfolane and dimethylsulfolane; nitriles such as benzonitrile; ketones such as methylphenylketone and mixtures thereof. -Methyl-2-pyrrolidone, 2-py Lolidon, N-methyl-ε-caprolactam, ε-caprolactam, hexamethylphosphoramide, N-dimethylpropylene urea, and 1,3-dimethyl-2-imidazolidinone having an aliphatic cyclic structure are preferred.

  The organic polar solvents (3) and (6) may be different, but are preferably the same because the separation operation is not required at the time of reuse.

  In the step (1d), the atmosphere when the organic polar solvent (6) is brought into contact with the crude reaction mixture or the solid (slurry) is not particularly limited. In the case where the polyarylene sulfide resin (4) or the organic polar solvent (6) is oxidatively degraded due to such conditions as above, it is desirable to perform the reaction in a non-oxidizing atmosphere. Note that the non-oxidizing atmosphere is an atmosphere in which the oxygen concentration in the gas phase is 5% by volume or less, preferably 2% by volume or less, and more preferably an atmosphere containing substantially no oxygen, ie, an inert gas atmosphere such as nitrogen, helium, or argon. It means that.

  In the present invention, the organic polar solvent ((3) and (6)) is subsequently subjected to solid-liquid separation from the reaction mixture (L1) to contain a cyclic polyarylene sulfide (2) and the compound (1). Step (2) of obtaining a reaction mixture (S2) is included.

  A method for removing the organic polar solvents ((3) and (6)) from the reaction mixture (L1) obtained as the filtrate component is, for example, a so-called flash method in which the solvent is recovered by evaporating the solvent and the solid is recovered at the same time. A method and removal of a solvent using a film can be exemplified. When removing the organic polar solvent, the solvent is removed so that the ratio of the solid (non-volatile content) is in the range of 20 to 100% by mass, preferably 20 to 99.99% by mass, and more preferably 30 to 90% by mass. It is desirable. The temperature at which the solvent is removed by heating cannot be uniquely limited because it depends on the characteristics of the solvent to be used. However, a temperature in the range of usually 20 to 150 ° C, preferably 40 to 120 ° C can be selected. Further, the pressure at which the solvent is removed is preferably equal to or lower than normal pressure, whereby the solvent can be removed at a lower temperature.

  In the present invention, the reaction mixture (S2) is then brought into contact with water at a temperature of more than 100 ° C. and a pH of 6 or more, whereby the compound (1a) represented by the structural formula (1a) and the cyclic polyarylene sulfide ( Step (3) includes a method of separating the step (2) from the step (2).

  The reaction mixture (S2) is subjected to a treatment (contact with water) under conditions of 100 ° C. or lower, preferably 20 to 100 ° C. as a pretreatment, if necessary, and then to a temperature above 100 ° C. At pH 6 or higher, it can be brought into contact with water.

  Examples of the water washing treatment that is performed as necessary include a method of adding water to the reaction mixture (S2), stirring the mixture, and then filtering the mixture using a filtration device, a filtration residue containing water obtained by the above-described filtration (hereinafter, “water-containing residue”). And the mixture is filtered after adding water again to form a slurry, or filtered by adding water again while the wet cake is held in a filter.

  The amount of water added in the optional water washing treatment is preferably in the range of 0.1 to 100 times the theoretical yield of the finally obtained cyclic polyarylene sulfide (2), It is more preferable to be in the range of 2 to 10 times from the viewpoint of cleaning efficiency. Further, it is preferable that the above amount of water is divided into 2 to 10 times, more preferably 2 to 4 times, and then subjected to water washing. The temperature of the water during the water washing treatment is preferably in the range of 50 to 90 ° C. from the viewpoint of improving the washing efficiency, and particularly preferably in the range of 70 to 90 ° C.

  The washing process performed as necessary can be performed a plurality of times as a batch process. When performing a plurality of times, for example, cleaning is performed at 50 to 90 ° C. When water washing is repeated a plurality of times, the temperature conditions may be the same or different.

  The reaction mixture (S2) containing the compound (1) and the cyclic polyarylene sulfide (2) is subjected to water washing treatment, if necessary, and then contacted with water at a pressure of more than 100 ° C. and a pH of 6 or more under pressurized conditions. Let it.

  The pressure is in the range of 0.02 to 0.1 [MPa]. In order to promote the dissolution of the compound (1) in water while exhibiting an excellent predetermined refining effect, the pressure is preferably 0.1 to 0.1 MPa. It is preferable to carry out at a pressure of 02 to 0.1 [MPa]. As a pressurized atmosphere, a mixed gas with an inert gas such as nitrogen gas, argon gas, or neon gas may be used from the viewpoint of safety, but air is most preferably used from the viewpoint of economy.

  The temperature at which the compound (1) is brought into contact with the cyclic polyarylene sulfide (2) and water under a pressurized condition is such that the solubility of the compound (1a) in water becomes more remarkable and the compound (1a) The temperature is higher than 100 ° C., preferably 120 ° C. or higher, more preferably 140 ° C. or higher, since the separation of the cyclic polyarylene sulfide (2) can be performed more efficiently. The upper limit of the temperature at this time is not particularly limited, but is preferably 200 ° C. or lower, more preferably 180 ° C. or lower.

When the compound (1) is brought into contact with the cyclic polyarylene sulfide (2) and water under pressurized conditions, an acid or a base is added to adjust the pH to 6 or more, preferably from 6.5 to 11.5. It is preferable to control the solubility of the compound (1a) in water and the like by adjusting the concentration.
In particular, when the pH is adjusted to 9.5 to 11.5 after hot water washing by adding a base during hot water washing at a temperature higher than 100 ° C., the acid type terminal (H-type terminal) of the compound (1a) becomes a basic type. It is preferable that the compound (1a) is further converted into a terminal (Na-type terminal), thereby further increasing the solubility of the compound (1a) in water.

  Examples of the acid used here include hydrochloric acid, sulfuric acid, carbonic acid, acetic acid and the like, and among these, carbonic acid and acetic acid are preferable. Examples of the basic compound used include alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, and potassium hydroxide, and sodium carbonate, ammonium carbonate, and sodium phosphate. Of these, sodium hydroxide is preferable. As a method of measuring the pH, for example, when an acid is added to the slurry, a method of measuring the pH of a filtrate obtained by filtering the slurry may be mentioned.

  The amount of water used when contacting the compound (1) with the cyclic polyarylene sulfide (2) under water under pressurized conditions is not particularly limited as long as water molecules are present as a liquid. If the pressure of the water in the closed system has reached the saturated vapor pressure at that temperature under pressurized conditions, the water exists as a liquid. In the present invention, the compound (1a) is efficiently used as the water. In order to dissolve the compound (1a), it is preferably in the range of 100 to 1,000 parts by mass, more preferably in the range of 100 to 1000 parts by mass, and still more preferably in the range of 200 to 800 parts by mass, based on 100 parts by mass of the compound (1a). preferable.

In the present invention, the contact between the compound (1), the cyclic polyarylene sulfide (2) and water under a pressurized condition may be carried out continuously or in a batch manner.
In the present invention, a container used when the compound (1) is brought into contact with the cyclic polyarylene sulfide (2) and water under a pressurized condition is a sealed type or a closed type capable of dissolving the compound (1a) in a liquid layer. It is a container having a mixing function that can be sealed, and any container can be used as long as the object of the present invention can be achieved.A stirring blade is provided inside the container, and a filter for filtration is provided at the bottom. Or a sealed container having a mixing function capable of being sealed.

  The reaction mixture (S2) containing the compound (1) and the cyclic polyarylene sulfide (2) is subjected to water washing treatment, if necessary, and then contacted with water at a pressure of more than 100 ° C. and a pH of 6 or more under pressurized conditions. After cooling to room temperature, the mixture is filtered if necessary, ion-exchanged water is added thereto, and the mixture is filtered again at a temperature in the range of 20 to 90 ° C. As a liquid phase component (filtrate component), a basic terminal (Na The compound (1a) converted to the (form end) is separated from the reaction mixture (S3) containing the compound (1b) and the cyclic polyarylene sulfide (2) as solids (filtration residue).

  The compound (1a) separated in this way and the reaction mixture (S3) are separately collected. The compound (1a) and the reaction mixture (S3) obtained by collection may be dried as they are to obtain a powder, or may be further washed several times with water, then solid-liquid separated, and dried. To obtain a powder. The amount of water used in the water washing treatment after hot water washing at a temperature higher than 100 ° C. is not particularly limited, but is preferably 1 to 100 times, more preferably 1 to 100 times the theoretical yield of the compound (1a) or the reaction mixture (S3). Is in the range of 2 to 10 times. Drying is performed by heating to a temperature at which water substantially evaporates. Drying may be performed under vacuum, or may be performed in air or under an inert atmosphere such as nitrogen.

  The compound (1a) obtained in the present invention is added as an additive in thermal oxidative crosslinking using, for example, a linear high-molecular-weight polyarylene sulfide resin, thereby suppressing viscosity increase during melting and thereby stabilizing the melting of the resin. A crosslinked polyarylene sulfide resin having a high crystallization rate at the time of molding and solidifying can be produced while improving the properties.

  The cyclic polyarylene sulfide (2) contained in the reaction mixture (S3) has the following structural formula (2)

(However, in the formula (2), m is 2 to 50, preferably 4 to 13. Ar ′ is an arylene group.) A cyclic polyarylene sulfide represented by the following formula: Ar ′ is a divalent arylene group obtained by removing two halogen atoms from the dihalo-aromatic compound, and when a polyhalo-aromatic compound is used in combination, It is a divalent arylene group obtained by removing two halogen atoms.

  The ratio of the cyclic polyarylene sulfide (2) to the compound (1b) in the reaction mixture (S3) is such that the cyclic polyarylene sulfide (2) / the compound (1b) is at least 50/50 on a mass basis. Is preferably in the range of 65/35 or more, while it is preferably in the range of 85/15 or less, and more preferably in the range of 80/20 or less.

  Further, the ratio of the total amount of the cyclic polyarylene sulfide (2) and the compound (1b) contained in the reaction mixture (S3) is preferably at least 95% by mass, and more preferably at least 98% by mass. More preferably, it is more preferably 99% by mass or more, while it is preferably 100% by mass or less, more preferably 99.9% or less, and 99.99% or less. More preferably, it is within the range.

  The reaction mixture (S3) had the following structural formulas (4) and (5) as remaining components.

(Wherein, Ar is an aryl group having a halogen atom, and Ar ′ is an arylene group.).

  In the present invention, subsequently, the reaction mixture (S3) is brought into contact with an organic polar solvent (7) to separate the compound (1b) represented by the following structural formula (1b) from the cyclic polyarylene sulfide (2). (4).

  The method of contacting the reaction mixture (S3) with the organic polar solvent (7) is not particularly limited. For example, the organic polar solvent (7) is mixed with the reaction mixture (S3), preferably at 10 to 200 ° C. Is contacted in the range of 50 to 150 ° C., more preferably 80 to 130 ° C., and then separated into a liquid phase component containing the cyclic polyarylene sulfide (2) and a solid component containing the compound (1b). The pressure at which the reaction mixture (S3) is brought into contact with the organic polar solvent (7) may be normal pressure or pressure, but may be performed under a pressure in the range of 0.1 to 0.5 [MPa]. preferable. There are no particular restrictions on the atmosphere in which the reaction mixture (S3) and the organic polar solvent (7) are brought into contact, but the cyclic polyarylene sulfide (2) or the organic polar solvent may be used depending on conditions such as the temperature and time for the contact. In the case where (7) is oxidatively degraded, it is desirable to perform the treatment in a non-oxidizing atmosphere. Note that the non-oxidizing atmosphere is an atmosphere in which the oxygen concentration in the gas phase is 5% by volume or less, preferably 2% by volume or less, and more preferably an atmosphere containing substantially no oxygen, ie, an inert gas atmosphere such as nitrogen, helium, or argon. It means that.

As the organic polar solvent (7) to be used, those which do not substantially cause undesired side reactions such as decomposition or crosslinking of the polyarylene sulfide resin (4) are preferable. For example, aromatic hydrocarbon solvents such as toluene and xylene, chloroform, Bromoform, methylene chloride, 1,2-dichloroethane, 1,1,1-trichloroethane, chlorobenzene, halogen solvents such as 2,6-dichlorotoluene, ether solvents such as diethyl ether, tetrahydrofuran, diisopropyl ether, formamide, acetamide, N-methylformamide, N, N-dimethylformamide, N, N-dimethylacetamide, tetramethylurea, N-methyl-2-pyrrolidone, 2-pyrrolidone, N-methyl-ε-caprolactam, ε-caprolactam, hexamethylphos Amides such as formamide, N-dimethylpropylene urea, 1,3-dimethyl-2-imidazolidinonic acid, urea and lactams, dimethyl sulfoxide, trimethyl phosphoric acid, polar solvents such as N, N-dimethylimidazolidinone, methyl ethyl ketone Can be exemplified. Among them, the organic polar solvent (7) is a polar solvent having a dipole moment μ of 1 [D] (* 1D = 3.3356 × 10 ⁻³⁰ C · m) or a dielectric constant ε (20 ° C.) of 2 or more. Those that are solvents are preferred.

  Thereafter, the separated liquid phase component and solid component are subjected to solid-liquid separation by a filtration operation or the like to obtain the compound (1b) through the step (5) of recovering the compound (1b), or to obtain the compound (1b) The cyclic polyarylene sulfide (2) can be obtained through the step (6) of recovering the arylene sulfide (2).

  In the step (6), the method of removing the organic polar solvent (7) in the liquid phase component may be, for example, a so-called flash method, in which the solvent is recovered by evaporating the solvent and a solid is recovered, or a method using a membrane. The removal of the solvent can be exemplified. When removing the organic polar solvent (7), the solvent is removed so that the ratio of non-volatile components is in the range of 20 to 100% by mass, preferably 20 to 99.99% by mass, and more preferably 30 to 90% by mass. Is desirable. The temperature at which the solvent is removed by heating cannot be uniquely limited because it depends on the characteristics of the solvent to be used. However, a temperature in the range of usually 20 to 150 ° C, preferably 40 to 120 ° C can be selected. Further, the pressure at which the solvent is removed is preferably equal to or lower than normal pressure, whereby the solvent can be removed at a lower temperature.

  When the reaction mixture (S3) contains the dimer to trimer components represented by the structural formulas (4) and (5), it is mainly recovered on the liquid phase component side. Therefore, in the step (4b) of recovering the liquid phase component, the proportion of the cyclic polyarylene sulfide (2) in the solid content obtained after removing the organic polar solvent is determined by the cyclic polyarylene sulfide ( 2) and preferably 90% by mass or more, more preferably 96% by mass or more, still more preferably 98% by mass or more, preferably 100% or less, based on the total amount of the dimer and the trimer. Preferably, it is in the range of 99.99% by mass or less.

  Thus, according to the present invention, the compound (1b) can be recovered with high purity by separating the cyclic polyarylene sulfide (2) through the steps (4) and (5). Therefore, the compound (1b) obtained in the present invention can be used as an additive in various resins, and a resin composition in which the compound (1b) is mixed with a polyarylene sulfide resin is used. Similar to the case of using the compound (1a), the product has a strong tendency to exhibit excellent fluidity at the time of melt processing, and is excellent not only in retention stability but also in the case of using the compound (1a). The generated gas at the time of melt molding can be suppressed as compared with the case.

  On the other hand, in the present invention, cyclic polyarylene sulfide can be recovered with high purity by separating the compound (1b) through the steps (4) and (6). Therefore, the cyclic polyarylene sulfide obtained in the present invention can be applied to various resins as a high-performance material or a functional material based on being a cyclic substance. Cyclic polyarylene sulfide can be used as a monomer, so that the polymerization reaction easily proceeds, and a high molecular weight polyarylene sulfide resin can be produced.

  When compounding the cyclic polyarylene sulfide (2) obtained according to the present invention or the compound (1b), a releasing agent, a colorant, a heat-resistant stabilizer, and an ultraviolet light stabilizer are used without departing from the object of the present invention. Known and commonly used additives such as a foaming agent, a rust preventive, a flame retardant, a lubricant, a coupling agent, and a filler. Further, similarly, the following synthetic resins and elastomers can be mixed and used. As these synthetic resins, polyester, polyamide, polyimide, polyetherimide, polycarbonate, polyphenylene ether, polysulfone, polyethersulfone, polyetheretherketone, polyetherketone, polyarylene, polyethylene, polypropylene, polytetrafluoroethylene, Examples thereof include polydifluoroethylene, polystyrene, ABS resin, epoxy resin, silicone resin, phenol resin, urethane resin, and liquid crystal polymer. Examples of the elastomer include polyolefin rubber, fluorine rubber, and silicone rubber.

  The composition obtained by blending the cyclic polyarylene sulfide (2) or the compound (1b) obtained according to the present invention was directly or once formed into pellets after melt-kneading, similarly to the conventional polyarylene sulfide resin. Thereafter, melt molding is performed by various melt processing methods such as injection molding, extrusion molding, compression molding, and blow molding to obtain a molded article having excellent heat resistance, molding workability, dimensional stability, and the like. Examples of the use of the molded product include electrical and electronic components such as connectors, printed circuit boards, and encapsulation molded products, automobile parts such as lamp reflectors and various electrical components, interior materials for various buildings and aircraft and automobiles, Alternatively, it can be widely used as injection molded / compressed products such as precision parts such as OA equipment parts, camera parts, watch parts, etc., or extruded / pull molded products such as fibers, films, sheets, pipes, etc.

  Hereinafter, the present invention will be described specifically with reference to examples. These examples are illustrative and not limiting.

(Example of measurement HPLC measurement)
The amount of CP-MABA was calculated by measuring the concentration of CP-MABA in the liquid by HPLC.
Sample preparation: When CP-MABA was contained in the organic solvent, the solvent was distilled off using an evaporator, and then a mobile phase of HPLC was added to the residue and dissolved to prepare a measurement sample. When CP-MABA was contained in the aqueous solution, it was prepared by adding the mobile phase as it was.
The measurement sample was subjected to HPLC measurement, and the concentration in the liquid was determined and calculated from the peak area and the calibration curve at the same retention time as the standard sample prepared by the following method.

(Synthesis of standard substance: CP-MABA)
83.4 g (1.0 mol) of a 48% aqueous NaOH solution and 297.4 g (3.0 mol) of N-methyl-2-pyrrolidone were charged into a pressure-resistant vessel equipped with a stirrer, and stirred at 230 ° C. for 3 hours. After completion of the stirring, the valve was opened at 230 ° C. and the pressure was released, and the pressure was reduced to 0.1 MPa at 230 ° C., which is about the vapor pressure of N-methyl-2-pyrrolidone, and water was distilled off. Then, it was closed again and the temperature was lowered to about 200 ° C.

  147.0 g (1.0 mol) of p-dichlorobenzene was dissolved by heating under a temperature condition of 60 ° C. or higher, and charged into the reaction mixture. After the temperature was raised to 250 ° C., the mixture was stirred for 4 hours. After the stirring was completed, the mixture was cooled to room temperature. The conversion of p-dichlorobenzene was 31 mol%. After cooling, the content was taken out, water was added and the mixture was stirred, and unreacted p-dichlorobenzene, which became insoluble, was removed by filtration.

  Next, hydrochloric acid was added to the aqueous solution as a filtrate to adjust the pH of the aqueous solution to 4. At this time, brown oily CP-MABA (hydrogen type) was generated in the aqueous solution. Chloroform was added thereto to extract a brown oily substance. The aqueous phase at this time was discarded because it contained N-methyl-2-pyrrolidone and its ring-opened product, 4-methylaminobutyric acid (hereinafter abbreviated as “MABA”). The chloroform phase was washed twice with water.

  In a state where water was added to the chloroform phase to form a slurry, a 48% aqueous solution of NaOH was added to adjust the pH of the slurry to 13. At this time, CP-MABA was transferred to the aqueous phase as a sodium salt, and the chloroform phase was discarded because p-chloro-N-methylaniline and N-methylaniline as by-products were dissolved in the chloroform phase. The aqueous phase was washed twice with chloroform.

  Dilute hydrochloric acid was added to the aqueous solution to adjust the pH of the aqueous solution to 1 or less. At this time, since CP-MABA becomes a hydrochloride and remains in the aqueous solution, chloroform was added to the aqueous solution to extract p-chlorophenol as a by-product. The chloroform phase in which p-chlorophenol was dissolved was discarded.

  A 48% aqueous NaOH solution was added to the remaining aqueous solution to adjust the pH of the aqueous solution to 4. As a result, CP-MABA hydrochloride was neutralized, and brown oily CP-MABA (hydrogen type) was precipitated from the aqueous solution. CP-MABA (hydrogen type) was extracted with chloroform, and chloroform was removed under reduced pressure to obtain CP-MABA (hydrogen type).

(HPLC measurement conditions)
Apparatus name: "High Performance Liquid Chromatogram Prominence" manufactured by Shimadzu Corporation
Column: "Phenomenex Luna 5u C18 (2) 100A" manufactured by Shimadzu GLC
Detector: DAD (Diode Array Detector)
Data processing: "LCsolution" manufactured by Shimadzu Corporation
Measurement conditions: Column temperature 40 ° C
Mobile phase: water flow rate 1.0 ml / min

(Measurement example FD-MASS)
FD-MS: Measured using "JMS-T100GC AccuTOF" manufactured by JEOL Ltd.
Measurement range: m / z = 4.00 to 2000.00
Rate of change: 51.2 mA / min
Final current value: 40 mA
Cathode voltage: -10 kV

(GPC measurement)
Measuring device: Tosoh Corporation HLC-8220GPC
Column: TSK-GUARDCOLUMN SuperHZ-L manufactured by Tosoh Corporation + TSK-GEL SuperHZM-M × 4 manufactured by Tosoh Corporation
Detector: RI (differential refractometer)
Data processing; Multi-station GPC-8020 model II manufactured by Tosoh Corporation Measurement conditions: Column temperature 40 ° C Solvent Tetrahydrofuran flow rate 0.35 ml / min Sample: 0.2 mass% tetrahydrofuran solution in terms of resin solid content filtered with a microfilter ( 100 μl)

(High temperature GPC measurement)
The mass average molecular weight was measured using a high temperature gel permeation chromatograph (GPC) SSC-7000 manufactured by Senshu Kagaku. The average molecular weight was calculated in terms of standard polystyrene.
Solvent: 1-chloronaphthalene Input port: 250 ° C
Temperature: 210 ° C
Detector: UV detector (360 nm)
Sample concentration: 1 g / L
Flow rate: 0.7 mL / min

(Measurement of nitrogen atom concentration in sample)
Nitrogen atom content in a sample using "TN Minus 2100H" manufactured by Mitsubishi Chemical Analytech Co., Ltd. in accordance with JIS K2609: 1998 (Crude oil and petroleum products / N2 test method Part 4: Chemiluminescence method) Was calculated.

(Measurement of chlorine atom concentration in sample)
Using “Total Organic Halogen Analyzer TOX-2100H” manufactured by Mitsubishi Chemical Analyck Co., Ltd., it was based on JIS K2170: 2013 (Annex A (normative) Method for testing chlorine content of regenerated heavy oil (combustion microcoulometric titration method)). The chlorine atom content in the sample was calculated by the method. However, this method was not performed with respect to burning the fuel oil diluted with toluene in the method. In addition, A.I. 2) 0.01 M hydrochloric acid (15 μL) was used instead of o) to r). The measurement conditions are as follows.
Oxygen flow rate (mL / min): 200
Argon flow rate (mL / min): 200
Combustion furnace temperature Inlet (° C): 900
Combustion furnace temperature Outlet (° C): 1000

(Example)
・ Process (1)
A pressure gauge, a thermometer, a stirring blade and a bottom valve with 150 l autoclave was connected capacitors, and flaky sodium sulfide (60.3 _wt% Na 2 S) 19,413 parts by weight, N- methyl-2-pyrrolidone 45000 The parts by mass were charged. The temperature was raised to 209 ° C. while stirring under a nitrogen stream to distill 4644 parts by mass of water (the amount of remaining water was 1.13 mol per mol of sodium sulfide). Thereafter, the autoclave was closed and cooled to 180 ° C., and 22185 parts by mass of paradichlorobenzene and 18000 parts by mass of NMP were charged. At a liquid temperature of 150 ° C., a nitrogen gas was used to pressurize to 0.1 MPa with a gauge pressure, and the temperature was raised. The reaction was allowed to proceed while stirring at a liquid temperature of 260 ° C. for 3 hours, and the autoclave was cooled by spraying water on the upper portion. Next, the temperature was lowered and the cooling at the top of the autoclave was stopped. During the cooling of the upper part of the autoclave, the liquid temperature was kept constant so as not to drop. The maximum pressure during the reaction was 0.85 MPa. After the reaction, the solution was cooled, and at a temperature of 170 ° C., a solution containing 284 parts by mass of oxalic acid dihydrate (2.25 parts by mass) in 663 parts by mass of NMP was injected under pressure, stirred for 30 minutes, and cooled.

  The bottom valve was opened at 100 ° C., the reaction slurry was transferred to a 150-liter flat plate filter, pressure-filtered at 120 ° C., 48,000 parts by mass of NMP was added, and the pressure cake was washed and filtered again.

・ Process (2)
500 parts by mass of the NMP filtrate was collected and charged in a 1 L eggplant-shaped flask, and NMP was removed by distillation at 150 ° C. under reduced pressure using a rotary evaporator to obtain a brown solid residue. Further, the residue was dried with a 210 ° C. hot air dryer for 1 hour to obtain 9.06 parts by mass of a solid residue (S2). After obtaining the results from FD-MASS measurement and HPLC measurement that the products contained in the solid residue (S2) are cyclic polyarylene sulfide, oligomer of linear polyarylene sulfide and Na-type CP-MABA Further, from the GPC measurement based on the results, 4.75 parts by mass of the cyclic polyarylene sulfide contained in the solid residue (S2), 2.04 parts by mass of the oligomer of the linear polyarylene sulfide, and Na type The result was that CP-MABA was 2.27 parts by mass.
In the present invention, a polymer having repeating units 2 to 40 (a mixture of dimers to 40-mers) may be referred to as an “oligomer”.

・ Process (3)
9.06 parts by mass of the obtained solid residue (S2) and 100 parts by mass of ion-exchanged water were charged into a 0.5 liter autoclave, and a 48% by mass aqueous NaOH solution was added to adjust the pH to 10.6. For 10 minutes. After cooling to room temperature, the mixture was filtered, and 100 parts by mass of ion-exchanged water at 70 ° C. was added to the filtered cake to wash the cake.

  The filtrate was collected, water was removed by distillation, and further dried with a hot air drier at 120 ° C. for 4 hours to obtain 2.24 parts by mass of a solid (L3) derived from the filtrate. From the FD-MASS measurement and the HPLC measurement, the result that the product contained in the solid (L3) was Na-type CP-MABA, and further from the GPC measurement based on the result, the solid (L3) ) Contained 2.24 parts by mass of Na-type CP-MABA, and the result was that 0 parts by mass of cyclic polyarylene sulfide and 0 parts by mass of linear polyarylene sulfide oligomer were obtained. The ratio (extraction rate) of Na-type CP-MABA contained in the solid (S3) to Na-type CP-MABA contained in the solid residue (S2) was 99 wt%.

  On the other hand, the solid content after removing the filtrate was dried with a 120 ° C. hot air drier for 4 hours to obtain 6.82 parts by mass of a filtration residue (S3). From the FD-MASS measurement and the HPLC measurement, the results that the products contained in the filtration residue (S3) were cyclic polyarylene sulfide, oligomer of linear polyarylene sulfide and Na-type CP-MABA were obtained. Thereafter, GPC measurement based on the results further showed that 4.75 parts by mass of the cyclic polyarylene sulfide, 2.04 parts by mass of the oligomer of the linear polyarylene sulfide contained in the filtration residue (S3), and 2.0% by mass of the Na type The result was that CP-MABA was 0.03 parts by mass. Further, the nitrogen content in the filtration residue (S3) was measured and found to be 110 μmol / g.

・ Process (4)
6.82 parts by mass of the dried filtration residue (S3) and 150 parts by mass of chloroform were charged into a 0.5-liter glass container, and stirred at 70 ° C. for 60 minutes. After cooling to room temperature, the mixture was filtered, and the cake after the filtration was washed with 150 parts by mass of chloroform at 25 ° C.

・ Step (5)
The solid content after the removal of the filtrate in the step (4) was dried with a hot air dryer at 120 ° C. for 4 hours to obtain 2.31 parts by mass of a filtration residue (S5). From the FD-MASS measurement and the HPLC measurement, it was obtained that the products contained in the filtration residue (S5) were cyclic polyarylene sulfide, oligomer of linear polyarylene sulfide and Na-type CP-MABA. Thereafter, the GPC measurement based on the results further showed that the linear polyarylene sulfide oligomer contained in the filtration residue (S5) contained 2.04 parts by mass, the cyclic polyarylene sulfide contained 0.24 parts by mass, and Na The type CP-MABA was 0.03 parts by mass.

  Moreover, when the nitrogen content and the chlorine content in the filtration residue (S5) were measured, they were 210 μmol / g and 370 μmol / g, respectively. Subsequently, FD-MASS measurement and high-temperature GPC measurement were performed on the filtration residue (S5), and it was confirmed that a linear polyarylene sulfide oligomer represented by the following structural formula was contained. FIG. 1 shows the results of the high-temperature GPC measurement. In addition, Mp = 1700, Mw = 6000, and Mw / Mp = 3.6.

(In the formula (1b ′), n is any one of 1 to 40, and X is a sodium atom.)

・ Process (6)
On the other hand, the filtrate removed during the solid-liquid separation in the filtration in the step (4) is collected, water is removed by distillation, and the solid (L6) 4 derived from the filtrate is dried by a 210 ° C. hot air drier for 1 hour. .51 parts by weight. From the FD-MASS measurement and the HPLC measurement, the product contained in the solid (L6) derived from the filtrate was determined to be a cyclic polyarylene sulfide. The shaped product (L6) contained 4.51 parts by mass of cyclic polyarylene sulfide, and was 0 parts by mass of linear polyarylene sulfide oligomer and 0 parts by mass of Na-type CP-MABA. The ratio (extraction rate) of the cyclic polyarylene sulfide contained in the solid (L6) to the cyclic polyarylene sulfide contained in the solid residue (S2) was 95 wt%. FIG. 2 shows the results of the FD-MASS measurement.

(Comparative Example 1)
In the above step (4), the same operation as in the above example was performed except that “n-hexane” was used instead of “chloroform”.

  The solid (L6 ′) derived from the filtrate obtained in the step (L6) is 0.14 parts by mass, and the solid (L6 ′) contains 0.14 parts by mass of the cyclic polyarylene sulfide. And 0 parts by mass of linear polyarylene sulfide oligomer and 0 parts by mass of Na-type CP-MABA. The ratio (extraction rate) of the cyclic polyarylene sulfide contained in the solid (L6 ') to the cyclic polyarylene sulfide contained in the solid residue (S2) was 3 wt%.

  On the other hand, the solid content obtained after removing the filtrate obtained in the step (5) was dried with a 120 ° C. hot air drier for 4 hours, and 6.68 parts by mass of a filtration residue (S5 ′) was obtained. In S5 ′), the linear polyarylene sulfide oligomer was 2.04 parts by mass, the cyclic polyarylene sulfide was 4.61 parts by mass, and the Na-type CP-MABA was 0.03 parts by mass. Moreover, when the nitrogen content and the chlorine content in the filtration residue (S5 ′) were measured, they were 73 μmol / g and 128 μmol / g, respectively.

(Comparative Example 2)
In the above step (4), the same operation as in the above example was performed, except that “methanol” was used instead of “chloroform”.

  The solid (L6 ″) derived from the filtrate obtained in the step (6) was 0.46 parts by mass, and the solid (L6 ″) contained 0.38 parts by mass of the cyclic polyarylene sulfide. And 0.05 parts by mass of linear polyarylene sulfide oligomer and 0.03 parts by mass of Na-type CP-MABA. The ratio (extraction rate) of the cyclic polyarylene sulfide contained in the solid (L6 ″) to the cyclic polyarylene sulfide contained in the solid residue (S2) was 8 wt%.

  On the other hand, the solid content after the removal of the filtrate obtained in the step (5) was dried with a 120 ° C. hot air drier for 4 hours, and 6.36 parts by mass of a filtration residue (S5 ″) was obtained. In S5 ″), the linear polyarylene sulfide oligomer was 1.99 parts by mass, the cyclic polyarylene sulfide was 4.37 parts by mass, and the Na-type CP-MABA was 0 parts by mass. Moreover, when the nitrogen content and the chlorine content in the filtration residue (S5 ″) were measured, they were 32 μmol / g and 90 μmol / g, respectively.

Claims (11)

In an organic polar solvent (3), a dihalo-aromatic compound is reacted with (i) an alkali metal sulfide or (ii) an alkali metal hydrosulfide and an alkali metal hydroxide to give the following structural formula A crude reaction mixture containing a compound (1) represented by (1), a cyclic polyarylene sulfide (2), an organic polar solvent (3), a polyarylene sulfide resin (4) and an alkali metal halide (5) is obtained. Step (1a), the crude reaction mixture is subjected to solid-liquid separation, and at least the polyarylene sulfide resin (4) and the alkali metal halide (5) are separated and removed, and at least the compound (1) and the cyclic polyarylene sulfide are removed. A step (1) comprising (2) and a step (1b) of obtaining a reaction mixture (L1) containing the organic polar solvent,
A step (2) of solid-liquid separating the organic polar solvent from the reaction mixture (L1) to obtain a reaction mixture (S2) containing the compound (1) and the cyclic polyarylene sulfide (2);
The compound (1a) represented by the structural formula (1a) is separated and removed by bringing the reaction mixture (S2) into contact with water at a temperature higher than 100 ° C. and at a pH of 6 or more. (3) obtaining a reaction mixture (S3) containing the compound (1b) and the cyclic polyarylene sulfide (2)
(4) separating the compound (1b) and the cyclic polyarylene sulfide (2) by contacting the reaction mixture (S3) with an organic polar solvent (7);
A method for producing a compound (1b) represented by the following structural formula (1b), comprising:
(In the formulas (1), (1a) and (1b), Ar is an aryl group having a halogen atom, Ar ′ is an arylene group, R ¹ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms or Represents a cyclohexyl group, R ² represents an alkylene group having 3 to 5 carbon atoms, X represents a hydrogen atom or an alkali metal atom, In formula (1), n = 0 to 40, and in formula (1b), n = 1 to 40)   The step (1) has a step (1d) in addition to the steps (1a) and (1b), and the step (1d) is obtained after the crude reaction mixture is subjected to solid-liquid separation. After the solid content is further contacted with an organic polar solvent (6), the polyarylene sulfide resin (4) is separated and removed, and the compound (1), the cyclic polyarylene sulfide (2) and the organic polar solvent The production method according to claim 1, wherein the step is a step of obtaining a reaction mixture (L1) containing a solvent. The method according to claim 1, wherein the organic polar solvent (7) is at least one selected from the group consisting of chloroform, xylene and tetrahydrofuran. The method according to claim 1, wherein the dihalo aromatic compound is a dihalogenated benzene. The organic polar solvent (3) is at least one selected from the group consisting of N-methyl-2-pyrrolidone, N-pyrrolidone, N-methyl-ε-caprolactam, ε-caprolactam, and 1,3-dimethyl-2-imidazolinone. The manufacturing method according to claim 1, wherein: In an organic polar solvent (3), a dihalo-aromatic compound is reacted with (i) an alkali metal sulfide or (ii) an alkali metal hydrosulfide and an alkali metal hydroxide to give the following structural formula A crude reaction mixture containing a compound (1) represented by (1), a cyclic polyarylene sulfide (2), an organic polar solvent (3), a polyarylene sulfide resin (4) and an alkali metal halide (5) is obtained. Step (1a), the crude reaction mixture is subjected to solid-liquid separation, and at least the polyarylene sulfide resin (4) and the alkali metal halide (5) are separated and removed, and at least the compound (1) and the cyclic polyarylene sulfide are removed. A step (1) comprising (2) and a step (1b) of obtaining a reaction mixture (L1) containing the organic polar solvent,
A step (2) of solid-liquid separating the organic polar solvent from the reaction mixture (L1) to obtain a reaction mixture (S2) containing the compound (1) and the cyclic polyarylene sulfide (2);
The compound (1a) represented by the structural formula (1a) is separated and removed by bringing the reaction mixture (S2) into contact with water at a temperature higher than 100 ° C. and at a pH of 6 or more. (3) obtaining a reaction mixture (S3) containing the compound (1b) and the cyclic polyarylene sulfide (2)
(4) separating the compound (1b) and the cyclic polyarylene sulfide (2) by contacting the reaction mixture (S3) with an organic polar solvent (7);
A method for producing a cyclic polyarylene sulfide (2), comprising:
(In the formulas (1), (1a) and (1b), Ar is an aryl group having a halogen atom, Ar ′ is an arylene group, R ¹ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms or Represents a cyclohexyl group, R ² represents an alkylene group having 3 to 5 carbon atoms, X represents a hydrogen atom or an alkali metal atom, In Formula (1), n = 0 to 40, and in Formula (1a), n = 1 to 40)   The step (1) has a step (1d) in addition to the steps (1a) and (1b), and the step (1d) is obtained after the crude reaction mixture is subjected to solid-liquid separation. After the solid content is further contacted with an organic polar solvent (6), the polyarylene sulfide resin (4) is separated and removed, and the compound (1), the cyclic polyarylene sulfide (2) and the organic polar solvent The production method according to claim 6, which is a step of obtaining a reaction mixture (L1) containing a solvent. The method according to claim 6, wherein the organic polar solvent (7) is at least one selected from the group consisting of chloroform, xylene and tetrahydrofuran. 7. The method according to claim 6, wherein the dihalo aromatic compound is a dihalogenated benzene. The organic polar solvent (3) is at least one selected from the group consisting of N-methyl-2-pyrrolidone, N-pyrrolidone, N-methyl-ε-caprolactam, ε-caprolactam, and 1,3-dimethyl-2-imidazolinone. The production method according to claim 6, wherein In an organic polar solvent (3), a dihalo-aromatic compound is reacted with (i) an alkali metal sulfide or (ii) an alkali metal hydrosulfide and an alkali metal hydroxide to give the following structural formula A crude reaction mixture containing a compound (1) represented by (1), a cyclic polyarylene sulfide (2), an organic polar solvent (3), a polyarylene sulfide resin (4) and an alkali metal halide (5) is obtained. Step (1a), the crude reaction mixture is subjected to solid-liquid separation, and at least the polyarylene sulfide resin (4) and the alkali metal halide (5) are separated and removed, and at least the compound (1) and the cyclic polyarylene sulfide are removed. A step (1) comprising (2) and a step (1b) of obtaining a reaction mixture (L1) containing the organic polar solvent,
A step (2) of solid-liquid separating the organic polar solvent from the reaction mixture (L1) to obtain a reaction mixture (S2) containing the compound (1) and the cyclic polyarylene sulfide (2);
The compound (1a) represented by the structural formula (1a) is separated and removed by bringing the reaction mixture (S2) into contact with water at a temperature higher than 100 ° C. and at a pH of 6 or more. (3) obtaining a reaction mixture (S3) containing the compound (1b) and the cyclic polyarylene sulfide (2)
(4) separating the compound (1b) and the cyclic polyarylene sulfide (2) by contacting the reaction mixture (S3) with an organic polar solvent (7);
Characterized by having
A method for separating a cyclic polyarylene sulfide (2) from the compound (1b).
(In the formulas (1), (1a) and (1b), Ar is an aryl group having a halogen atom, Ar ′ is an arylene group, R ¹ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms or Represents a cyclohexyl group, R ² represents an alkylene group having 3 to 5 carbon atoms, X represents a hydrogen atom or an alkali metal atom, In formula (1), n = 0 to 40, and in formula (1b), n = 1 to 40)