JP6179945B2 - Process for producing polyarylene sulfide - Google Patents

Description

  The present invention relates to a method for producing polyarylene sulfide.

  Polyarylene sulfide (PAS) such as polyphenylene sulfide (PPS) is produced by polycondensation of paradichlorobenzene and sodium sulfide in a lactam solvent such as N-methylpyrrolidone. In this reaction, NaCl is produced as a by-product in forming the carbon-sulfur bond, which is not necessarily a preferable method from the viewpoint of the atom economy. In addition, due to environmental problems in recent years, chlorine remaining in the polymer is partly regarded as a problem.

  Further, as a PAS synthesis method that does not produce NaCl as a by-product, a method of synthesizing PAS by polymerization of disulfides can be mentioned. In many cases, this polymerization method uses a solvent such as dichloromethane at room temperature to form a sulfonium cation from disulfides, and repeats the Friedel-Crafts type addition reaction to form a PAS skeleton (for example, patents). References 1-8 and non-patent references 1-3).

Japanese Patent Laid-Open No. 63-213526 Japanese Unexamined Patent Publication No. 63-213527 JP 63-244102 A JP-A-2-169626 JP-A-4-55434 JP-A-4-57830 Japanese Patent Laid-Open No. 11-12359 JP 2008-163223 A

Macromolecules, 1992,25, 2698-2704 Bull.Chem.Soc.Jpn., 1994, 67, 251-256 Bull.Chem.Soc.Jpn., 1994, 67, 1456-1461

  However, in the above-described PAS synthesis method using disulfides, it is important to use a strong acid such as trifluoromethanesulfonic acid or its anhydride. These strong acids and their anhydrides are generally expensive, and a method that does not use them is required.

  Then, an object of this invention is to provide the novel manufacturing method of polyarylene sulfide which can manufacture polyarylene sulfide, without using a strong acid.

To achieve the above object, the present invention provides (A) a vanadium compound, (B) a boron compound represented by the following general formula (I), and (C) a substituted or unsubstituted compound in the presence of an oxidizing agent. A process for polymerizing a monomer containing diphenyl disulfide and / or a substituted or unsubstituted thiophenol under a reaction temperature exceeding 100 ° C. is provided.
RBX ₄ (I)
[Wherein, R represents Li, Na, K, Cs, a hydrocarbon group having 1 to 30 carbon atoms, or a silyl group in which three hydrocarbon groups having 1 to 30 carbon atoms are substituted, and X represents a halogen atom. Show. ]

In the production method of the present invention, a boron compound represented by (B) general formula (I) is used. The boron compound (B) having such a specific structure exists as BX ₄ ⁻ (anion) very stably and has a function of stabilizing vanadium without inhibiting the catalytic action by coordination to vanadium. In addition, for the protons generated in the main polymerization, since the boron compound (B) is an art complex, it does not form a strong bond with the protons and functions in the same manner as a strong acid used conventionally. Therefore, in the production method of the present invention, polyarylene sulfide can be produced without using a strong acid by using the boron compound (B) having the specific structure. Here, the following effects are produced when the boron compound (B) contains a halogen atom as a constituent element. That is, the BX ₄ ⁻ (anion) of the art complex is sufficiently stabilized by the halogen atom, and the anion and (A) the vanadium compound can exhibit a catalytic action having a high polymerization ability equivalent to that in the case of using a strong acid. And polyarylene sulfide can be produced. Moreover, superposition | polymerization will advance by setting the reaction temperature of a superposition | polymerization process to the temperature exceeding 100 degreeC. Furthermore, since the production method of the present invention uses substituted or unsubstituted diphenyl disulfide and / or substituted or unsubstituted thiophenol as a raw material monomer, NaCl is not generated as a by-product, from the viewpoint of atom economy and environmental problems. Is also preferable.

  In the method for producing polyarylene sulfide of the present invention, the (A) vanadium compound is preferably an oxo vanadium compound. Thereby, a polymerization reaction can be advanced more efficiently and the molecular weight of PAS obtained can be improved more.

  In the method for producing polyarylene sulfide of the present invention, in the general formula (I), X is preferably a fluorine atom. When X is a fluorine atom, the stability of the anion of the art complex is improved, and a catalyst having a higher polymerization ability can be formed with the (A) vanadium compound, and a PAS having a higher molecular weight can be produced. It becomes possible. In addition, the compound represented by the above general formula (I) in which X is a fluorine atom has an advantage that it is easily available.

  Furthermore, in the method for producing polyarylene sulfide of the present invention, the (C) oxidizing agent is preferably a gas containing oxygen molecules. Thereby, a polymerization reaction can be advanced more efficiently and the molecular weight of PAS obtained can be improved more.

  In the method for producing polyarylene sulfide of the present invention, the monomer contains at least one of unsubstituted diphenyl disulfide and unsubstituted thiophenol, and at least one of substituted diphenyl disulfide and substituted thiophenol. Also good. In this case, the molecular weight of the obtained PAS can be further improved.

  ADVANTAGE OF THE INVENTION According to this invention, the novel manufacturing method of polyarylene sulfide which can manufacture polyarylene sulfide can be provided, without using a strong acid.

  Hereinafter, the present invention will be described in detail with reference to preferred embodiments thereof.

The method for producing a polyarylene sulfide of the present invention comprises (A) a vanadium compound, (B) a boron compound represented by the following general formula (I), and (C) a substituted or unsubstituted compound in the presence of an oxidizing agent. It has a step of polymerizing a monomer containing diphenyl disulfide and / or a substituted or unsubstituted thiophenol under conditions where the reaction temperature exceeds 100 ° C. (hereinafter sometimes referred to as “polymerization step”).
RBX ₄ (I)
[Wherein, R represents Li, Na, K, Cs, a hydrocarbon group having 1 to 30 carbon atoms, or a silyl group in which three hydrocarbon groups having 1 to 30 carbon atoms are substituted, and X represents a halogen atom. Show. ]

  In the polymerization step, a substituted or unsubstituted diphenyl disulfide and / or a substituted or unsubstituted thiophenol is used as a monomer as a raw material for polyarylene sulfide. Diphenyl disulfide and thiophenol may be used in combination with a substituted one and an unsubstituted one, respectively. That is, the monomer that is a raw material for polyarylene sulfide includes one or more monomers selected from the group consisting of substituted diphenyl disulfide, unsubstituted diphenyl disulfide, substituted thiophenol, and unsubstituted thiophenol.

［式（ＩＩ）中、Ｒ^１、Ｒ^２、Ｒ^３、Ｒ^４、Ｒ^５、Ｒ^６、Ｒ^７及びＲ^８は、それぞれ独立に水素原子、炭素数１〜８のアルキル基、アラルキル基又はアリール基を表す。］ Examples of the substituted or unsubstituted diphenyl disulfide include compounds represented by the following general formula (II).

[In the formula (II), R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ and R ⁸ are each independently a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an aralkyl group or Represents an aryl group. ]

  Specific examples of the compound represented by the general formula (II) include diphenyl disulfide, 2,2′-dimethyldiphenyl disulfide, 3,3′-dimethyldiphenyl disulfide, 2,2 ′, 6,6′-tetramethyl. Diphenyl disulfide, 2,2 ′, 3,3′-tetramethyldiphenyl disulfide, 2,2 ′, 5,5′-tetramethyldiphenyl disulfide, 3,3 ′, 5,5′-tetramethyldiphenyl disulfide, 2, 2 ′, 3,3 ′, 5,5′-hexamethyldiphenyl disulfide, 2,2 ′, 3,3 ′, 6,6′-hexamethyldiphenyl disulfide, 2,2 ′, 3,3 ′, 5 5 ', 6,6'-octamethyldiphenyl disulfide, 2,2'-diethyldiphenyl disulfide, 3,3'-diethyldiphenyl disulphide Fido, 2,2 ′, 6,6′-tetraethyldiphenyl disulfide, 2,2 ′, 3,3′-tetraethyldiphenyl disulfide, 2,2 ′, 5,5′-tetraethyldiphenyl disulfide, 3,3 ′, 5 , 5′-tetraethyldiphenyl disulfide, 2,2 ′, 3,3 ′, 5,5′-hexaethyldiphenyl disulfide, 2,2 ′, 3,3 ′, 6,6′-hexaethyldiphenyl disulfide, 2, 2 ', 3,3', 5,5 ', 6,6'-octaethyl diphenyl disulfide, 2,2'-dipropyl diphenyl disulfide, 3,3'-dipropyl diphenyl disulfide, 2,2', 6 6'-tetrapropyldiphenyl disulfide, 2,2 ', 3,3'-tetrapropyldiphenyl disulfide, 2,2', 5,5'- Trapropyl diphenyl disulfide, 3,3 ′, 5,5′-tetrapropyl diphenyl disulfide, 2,2 ′, 3,3 ′, 5,5′-hexapropyl diphenyl disulfide, 2,2 ′, 3,3 ′, 6,6′-hexapropyldiphenyl disulfide, 2,2 ′, 3,3 ′, 5,5 ′, 6,6′-octapropyldiphenyl disulfide, 2,2′-diisopropyldiphenyl disulfide, 3,3′-diisopropyl Diphenyl disulfide, 2,2 ′, 6,6′-tetraisopropyl diphenyl disulfide, 2,2 ′, 3,3′-tetraisopropyl diphenyl disulfide, 2,2 ′, 5,5′-tetraisopropyl diphenyl disulfide, 3, 3 ′, 5,5′-tetraisopropyldiphenyl disulfide, 2,2 ′, 3 3 ′, 5,5′-hexaisopropyldiphenyl disulfide, 2,2 ′, 3,3 ′, 6,6′-hexaisopropyldiphenyl disulfide, 2,2 ′, 3,3 ′, 5,5 ′, 6 Examples include 6'-octaisopropyldiphenyl disulfide. Among these, from the viewpoint of raw material availability, diphenyl disulfide, 2,2′-dimethyldiphenyl disulfide, 3,3′-dimethyldiphenyl disulfide, 2,2 ′, 6,6′-tetramethyldiphenyl disulfide, 2,2 ', 3,3'-tetramethyldiphenyl disulfide, 2,2', 5,5'-tetramethyldiphenyl disulfide, 3,3 ', 5,5'-tetramethyldiphenyl disulfide, 2,2', 3,3 ', 5,5'-hexamethyldiphenyl disulfide, 2,2', 3,3 ', 6,6'-hexamethyldiphenyl disulfide, 2,2', 3,3 ', 5,5', 6,6 '-Octamethyldiphenyl disulfide can be preferably used.

［式（ＩＩＩ）中、Ｒ^９、Ｒ^１０、Ｒ^１１及びＲ^１２は、それぞれ独立に水素原子、炭素数１〜８のアルキル基、アラルキル基又はアリール基を表す。］ These substituted or unsubstituted diphenyl disulfides can also be easily prepared by oxidation of a substituted or unsubstituted thiophenol. Therefore, in the polymerization step, substituted or unsubstituted thiophenol can also be used as a precursor of the above-mentioned substituted or unsubstituted diphenyl disulfide. Examples of the substituted or unsubstituted thiophenol include compounds represented by the following general formula (III).

[In formula (III), R < ⁹ >, R < ¹⁰ >, R < ¹¹ > and R < ¹² > represent a hydrogen atom, a C1-C8 alkyl group, an aralkyl group, or an aryl group each independently. ]

  Specific examples of the compound represented by the general formula (III) include compounds that are precursors of the specific examples of the compound represented by the general formula (II). Among these, availability of raw materials From the viewpoint of thiophenol (benzenethiol), 2-methylbenzenethiol, 3-methylbenzenethiol, 2,3-dimethylbenzenethiol, 2,5-dimethylbenzenethiol, 2,6-dimethylbenzenethiol, 3,5 -Dimethylbenzenethiol can be preferably used. These substituted or unsubstituted thiophenols can be used in the same manner as the above-mentioned substituted or unsubstituted diphenyl disulfide. Even if a substituted or unsubstituted diphenyl disulfide is used or a substituted or unsubstituted thiophenol as a precursor thereof is used, the presence or type of the substituent is the same as the PAS. Things are obtained.

  In addition, when diphenyl disulfide having a substituent and / or thiophenol having a substituent is used as a monomer in the polymerization step, the solubility of the synthesized polymer in the monomer and / or solvent is improved, and a higher molecular weight body is obtained. There is a tendency to be obtained. In particular, it is preferable that the substituent is an alkyl group having 1 to 8 carbon atoms, an aralkyl group, or an aryl group because the synthesized polymer is more easily dissolved by the monomer and / or solvent and the molecular weight is increased. The aralkyl group preferably has 7 to 14 carbon atoms, and the aryl group preferably has 6 to 14 carbon atoms. It is preferable for the carbon number to be within the above range because the synthesized polymer is more easily dissolved by the monomer and has a higher molecular weight. In addition, when diphenyl disulfide having no substituent and / or thiophenol having no substituent is used, the availability of raw materials is extremely high compared to those having a substituent, which is industrially advantageous. The same polymer as conventional polyphenylene sulfide can be synthesized. The production method of the present invention is a method suitable for producing any of polyphenylene sulfide having no substituent and polyphenylene sulfide having a substituent. The above-mentioned substituted or unsubstituted diphenyl disulfide and substituted or unsubstituted thiophenol can be used singly or in combination of two or more.

  The monomer may be at least one of unsubstituted diphenyl disulfide and unsubstituted thiophenol (hereinafter referred to as “unsubstituted monomer”) and at least one of substituted diphenyl disulfide and substituted thiophenol (hereinafter referred to as “substituted monomer”). It is also preferable that it is included. Thus, by copolymerizing a substituted monomer with an easily available unsubstituted monomer, it is industrially advantageous, but compared with the case where the unsubstituted monomer is used alone, the monomer and / or Or the solubility with respect to a solvent can be improved, and a higher molecular weight polymer can be obtained. The ratio between the unsubstituted monomer and the substituted monomer is not particularly limited. In order to obtain a polymer having desired physical properties, the ratio of the unsubstituted monomer and the substituted monomer may be determined as appropriate.

［式（ＩＶ）中、Ｒ^１３、Ｒ^１４、Ｒ^１５及びＲ^１６はそれぞれ独立に、炭素数１〜６のアルキル基、又は、炭素数６〜８のアリール基を表し、Ｒ^１７及びＲ^１８はそれぞれ独立に、水素原子、炭素数１〜６のアルキル基、又は、炭素数６〜８のアリール基を表す。］ (A) A vanadium compound functions as an oxidation polymerization catalyst for the above monomer. As the (A) vanadium compound, an oxo vanadium compound having a V═O bond in the molecule is preferably used. Specific examples of the oxovanadium compound include N, N′-bissalicylideneethylenediamine oxovanadium, phthalocyanine oxovanadium, and tetraphenylporphyrin oxovanadium. In addition, a vanadium compound represented by the following general formula (IV) is also used.

[In Formula (IV), R ¹³ , R ¹⁴ , R ¹⁵ and R ¹⁶ each independently represent an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 8 carbon atoms, and R ¹⁷ and R ¹⁸ Each independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 8 carbon atoms. ]

As the vanadium compound represented by the general formula (IV), any vanadium compound having a structure in which two molecules of an anion of β-diketone is added to tetravalent oxo vanadium can be used. Specific examples include vanadyl (IV) acetylacetonate, vanadyl (IV) benzoylacetonate (R ¹³ = R ¹⁶ = methyl group, R ¹⁴ = R ¹⁵ = phenyl group, R ¹⁷ = R ¹⁸ = hydrogen atom. It is done.

  The above-mentioned (A) vanadium compound can be used alone or in combination of two or more.

  (A) The addition amount of the vanadium compound is preferably 0.001 to 100 mol with respect to 100 mol of the total amount of substituted or unsubstituted diphenyl disulfide and substituted or unsubstituted thiophenol, More preferably, it is -50 mol. When the addition amount is small, the polymerization reaction hardly proceeds, and when the addition amount is large, the (A) vanadium compound tends to remain in the obtained polymer.

  In the polymerization step, (B) a boron compound represented by the above general formula (I) is used. (B) Specific examples of the boron compound include, for example, lithium tetrafluoroborate, sodium tetrafluoroborate, potassium tetrafluoroborate, cesium tetrafluoroborate, methyltetrafluoroborate, ethyltetrafluoroborate, propyltetrafluoroborate, isopropyltetra Fluoroborate, butyltetrafluoroborate, isobutyltetrafluoroborate, tertiary butyltetrafluoroborate, pentyltetrafluoroborate, hexyltetrafluoroborate, cyclohexyltetrafluoroborate, phenyltetrafluoroborate, benzyltetrafluoroborate, xylyltetrafluoroborate , Diphenylmethyltetrafluoroborate, triphenylmethylte Rafluoroborate, trimethylsilyltetrafluoroborate, triphenylsilyltetrafluoroborate, tertiary butyldimethylsilyltetrafluoroborate, lithium tetrachloroborate, sodium tetrachloroborate, potassium tetrachloroborate, cesium tetrachloroborate, methyltetrachloroborate, Ethyltetrachloroborate, propyltetrachloroborate, isopropyltetrachloroborate, butyltetrachloroborate, isobutyltetrachloroborate, tertiary butyltetrachloroborate, pentyltetrachloroborate, hexyltetrachloroborate, cyclohexyltetrachloroborate, phenyltetrachloro Borate, benzyltetrachloroborate, xylyl Trachloroborate, diphenylmethyltetrachloroborate, triphenylmethyltetrachloroborate, lithium tetrabromoborate, sodium tetrabromoborate, potassium tetrabromoborate, cesium tetrabromoborate, methyltetrabromoborate, ethyltetrabromoborate, propyltetrabromo Borate, isopropyltetrabromoborate, butyltetrabromoborate, isobutyltetrabromoborate, tertiary butyltetrabromoborate, pentyltetrabromoborate, hexyltetrabromoborate, cyclohexyltetrabromoborate, phenyltetrabromoborate, benzyltetrabromoborate, key Silyltetrabromoborate, diphenylmethyltetrabromoborate, Liphenylmethyltetrabromoborate, lithium tetraiodoborate, sodium tetraiodoborate, potassium tetraiodoborate, cesium tetraiodoborate, methyltetraiodoborate, ethyltetraiodoborate, propyltetraiodoborate, isopropyltetraiodoborate, butyltetraiodo Borate, isobutyltetraiodoborate, tertiary butyltetraiodoborate, pentyltetraiodoborate, hexyltetraiodoborate, cyclohexyltetraiodoborate, phenyltetraiodoborate, benzyltetraiodoborate, xylyltetraiodoborate, diphenylmethyltetraiodoborate And triphenylmethyltetraiodoborate.

  (B) From the viewpoint of solubility, the boron compound is preferably a compound in which R is a phenylalkyl group, diphenylalkyl group, triphenylalkyl group, or tertiary alkyl group in general formula (I). Is more preferably a compound having a triphenylalkyl group or a tertiary alkyl group, and particularly preferably a compound in which R is a triphenylmethyl group or a tertiary butyl group. When the cation solubility is high, the function as a catalyst is easily exhibited.

  These (B) boron compounds can be used singly or in combination of two or more.

  (B) The addition amount of the boron compound is preferably 0.001 to 100 mol with respect to 100 mol of the total amount of substituted or unsubstituted diphenyl disulfide and substituted or unsubstituted thiophenol, More preferably, it is -50 mol. When this addition amount is small, the reaction hardly proceeds, and when the addition amount is large, the (B) boron compound tends to remain in the polymer.

［式（Ｖ）中、Ｒｆは炭素数１〜８のパーフルオロアルキル基を示す。］ In the polymerization step, together with the above-described (B) boron compound, a conventionally used acid can be used in combination from the viewpoint of promoting the reaction. As the acid, in addition to acids such as sulfuric acid, acetic acid, methane sulfonic acid, benzene sulfonic acid, and toluene sulfonic acid, organic acids represented by the following general formula (V) can also be used.

[In the formula (V), Rf represents a perfluoroalkyl group having 1 to 8 carbon atoms. ]

  Specific examples of the organic acid represented by the general formula (V) include trifluoromethanesulfonic acid, 1,1,2,2-tetrafluoroethanesulfonic acid, pentafluoroethanesulfonic acid, heptafluoropropanesulfonic acid, hepta. Examples thereof include fluoroisopropane sulfonic acid, nonafluorobutane sulfonic acid, and Nafion (registered trademark). Moreover, the anhydride of these compounds can also be used. Of these, trifluoromethanesulfonic acid and 1,1,2,2-tetrafluoroethanesulfonic acid are preferably used from the viewpoint of availability.

［式（ＶＩ）中、Ｒｆは炭素数１〜８のパーフルオロアルキル基を示す。］ Moreover, the organic acid represented with the following general formula (VI) can also be used similarly to the organic acid represented with the said general formula (V).

[In formula (VI), Rf represents a C 1-8 perfluoroalkyl group. ]

  Specific examples of the organic acid represented by the general formula (VI) include trifluoroacetic acid and pentafluoropropionic acid. Moreover, the anhydride of these compounds can also be used.

  When the acid is added, the addition amount is preferably 0.001 to 100 mol with respect to 100 mol of the total amount of substituted or unsubstituted diphenyl disulfide and substituted or unsubstituted thiophenol. More preferably, it is 01-50 mol. If the addition amount is small, the effect of promoting the reaction is low, and if the addition amount is large, the acid tends to remain in the polymer. In addition, it is preferable not to add an acid in a polymerization process from a viewpoint of improving problems, such as corrosion of a metal container by an acid. In the present invention, since the boron compound represented by (B) general formula (I) is used, the polymerization reaction can sufficiently proceed without adding an acid. Further, even when an acid is added, the amount added can be reduced.

  (C) The oxidizing agent is used for effectively functioning the (A) vanadium compound as an oxidation polymerization catalyst. (C) Specifically as an oxidizing agent, dicyanodichlorobenzoquinone, chloranil, bromanyl, 1,4-diphenoquinone, tetramethyldiphenoquinone, tetracyanoquinodimethane, tetracyanoethylene, perbenzoic acid, metachloroperbenzoic acid, Examples thereof include lead tetraacetate, thallium acid acetate, cerium (IV) acetylacetonate, manganese (III) acetylacetonate, and gas containing oxygen molecules such as oxygen gas and air. Among these, a gas containing oxygen molecules is preferable. Specific examples of the gas containing oxygen molecules include air, oxygen gas, and a mixture of oxygen and an inert gas such as nitrogen or argon. Among these, in addition to oxygen gas and air, a mixture of oxygen and nitrogen is preferably used. When a mixture of oxygen and nitrogen is used, the oxygen concentration is arbitrary.

  (C) oxidizing agent mentioned above can be used individually by 1 type or in combination of 2 or more types.

  In the polymerization step, it is important that the reaction temperature exceeds 100 ° C. At a reaction temperature of 100 ° C. or lower, it is difficult to remove water produced as a by-product in the polymerization out of the system, and thus the polymerization is difficult to proceed.

  The reaction temperature in the polymerization step needs to be higher than 100 ° C., more preferably 110 ° C. or higher, from the viewpoint of efficiently proceeding the polymerization reaction and obtaining PAS having a higher molecular weight.

  In the present invention, when a gas such as a gas containing oxygen molecules is used as the (C) oxidant, the pressure is not particularly limited, and normal pressure to 10 MPa is preferably selected. Excessive pressure is not preferable because it requires a thicker device and increases costs. In particular, when the pressure is high and the temperature is high, oxygen is oxidized at the sulfide site of the resulting polyarylene sulfide to give sulfoxide or sulfone, so care must be taken. Considering this point, the pressure is preferably about normal pressure to 1 MPa. The gas supply method may be a continuous type or a batch type.

  In the present invention, the reaction time in the polymerization step is not particularly limited, but is usually 0.1 to 240 hours. When the reaction time is shorter than 0.1 hour, the desired polymerization tends not to proceed. On the other hand, when reaction time exceeds 240 hours, possibility that a sulfoxide and a sulfone will be formed will become high. A suitable reaction time is 1 to 50 hours, more preferably 2 to 48 hours.

  In this invention, a solvent can be used for reaction as needed. Preferred solvents include dichloromethane, chloroform, carbon tetrachloride, 1,2-dichloroethane, tetrachloroethylene, 1,1,2,2-tetrachloroethane, nitromethane, nitrobenzene, N-methylpyrrolidone, chlorobenzene, dichlorobenzene and the like.

  In the polymerization step, it is also possible to sequentially add a monomer containing a substituted or unsubstituted diphenyl disulfide and / or a substituted or unsubstituted thiophenol during the polymerization reaction. In the latter stage of the reaction, the concentration of the monomer to be reacted decreases despite the fact that the catalyst (A) vanadium compound maintains its activity, so that there is a problem that the polymerization reaction hardly proceeds. By appropriately adding a monomer, the termination of polymerization can be prevented.

  Since there is a possibility that (A) vanadium compound or (B) boron compound remains in the polymer obtained in the polymerization step, it is preferable to wash the obtained polymer. There is no particular limitation on the cleaning method. For example, the obtained polymer can be pulverized to extract unreacted monomers and oligomer components with an organic solvent. The remaining polymer can be washed with water, acid, base or the like. It is also possible to completely or partially dissolve the obtained polymer in a solvent and wash it with water, acid, base or the like. Solvents usable at this time include dichloromethane, chloroform, carbon tetrachloride, 1,2-dichloroethane, tetrachloroethylene, 1,1,2,2-tetrachloroethane, nitromethane, nitrobenzene, chlorobenzene, dichlorobenzene, N-methylpyrrolidone and the like. Can be mentioned. Since unreacted monomers and oligomers are eluted in such a solvent, the recovered oligomers and monomers can be reused as raw materials by purification as necessary. In general, since polyarylene sulfide has low solubility in a solvent, it is necessary to add a solvent at least 4 times the mass of the polymer and to heat to 150 ° C. or higher. The solution is preferably washed with water, acid, base or the like. When these water-based cleaning agents are used, it is important to wash in a pressure vessel in order to contact with a solution having a temperature equal to or higher than the boiling point of water. In the laboratory, the polymer obtained is ground in a mortar, dispersed in dichloromethane, and washed with a mixture of methanol and hydrochloric acid. You may wash | clean by such a method.

  In addition, an extraction operation can be added to remove low molecular weight components from the polymer washed by the above method. Solvents that can be used in this case include dichloromethane, chloroform, carbon tetrachloride, 1,2-dichloroethane, tetrachloroethylene, 1,1,2,2-tetrachloroethane, nitromethane, nitrobenzene, chlorobenzene, dichlorobenzene, N described above. -In addition to methylpyrrolidone and the like, toluene, xylene, acetone and the like can also be used. The extracted low molecular weight component can be subjected to polymerization again after removing the solvent as appropriate.

  In the present invention, it is also possible to perform polymerization in a multistage manner using two or more kinds of various conditions such as temperature. At that time, it is possible to carry out polymerization under new conditions by transferring the contents to another reactor even by changing the conditions using the same reactor.

  According to the production method of the present invention described above, polyarylene sulfide can be polymerized with high yield by using a specific boron compound without using a strong acid.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to a following example. In addition, the measuring method of melting | fusing point and molecular weight of the polymer obtained by the Example and the comparative example is as follows. The yield, melting point and molecular weight of the polymers (purified PPS) obtained in Examples and Comparative Examples are shown in Table 1.

(Measurement of melting point)
The melting point was measured using a differential scanning calorimeter (manufactured by Seiko Denshi Kogyo Co., Ltd.) using α-alumina as a reference. The measurement conditions were such that the peak of the endothermic peak when the temperature was raised from room temperature to 310 ° C. at 20 ° C./min was the melting point.

(Measurement of molecular weight)
Two columns (PL gel 10 μm MIXED-B LS) were connected to a high-temperature GPC apparatus (manufactured by Polymer Laboratories, trade name: PL-220) to obtain a differential refractive index detector. 1 ml of 1-chloronaphthalene solvent was added to 10 mg of the sample, and the mixture was heated and stirred at 220 ° C. for about 30 minutes. The sample dissolved in this manner was analyzed at a flow rate of 0.7 ml / min to measure the molecular weight (number average molecular weight Mn and weight average molecular weight Mw).

[Example 1]
Diphenyl disulfide (5 g) is added to a 50 ml three-necked flask, and N, N′-bissalicylideneethylenediamineoxovanadium (VO (salen)) and triphenylmethyltetrafluoroborate (Ph ₃ C-BF ₄ ) are added. , diphenyl disulfide in a molar _{ratio: VO (salen): Ph 3} C-BF 4 = 100: 5: was added to a 10. While stirring the inside of the flask with a stirrer chip, it was heated to 160 ° C. in an oil bath, and atmospheric oxygen gas was introduced into the three-necked flask at a flow rate of 10 ml / min. After 20 hours, the oxygen supply was stopped, the oil bath was removed, and the system was cooled to room temperature. The obtained polymer was pulverized, dispersed in 200 ml of dichloromethane, and purified by precipitation with hydrochloric acid acidic methanol. The precipitate was filtered and dried under reduced pressure to obtain purified polyphenylene sulfide (PPS). The obtained purified PPS had a yield of 69%, a melting point (Tm) = 202 ° C., Mn = 850, and Mw = 1700.

[Example 2]
Purified PPS was obtained in the same manner as in Example 1, except that 9: 1 mixture (molar ratio) of diphenyl disulfide and 2,2 ′, 5,5′-tetramethyldiphenyl disulfide was used instead of diphenyl disulfide. It was. The obtained purified PPS had a yield of 83%, a melting point = 254 ° C., Mn = 1700, and Mw = 3300.

[Example 3]
Example except that vanadyl tetraphenylporphyrin (VOTPP) was used instead of VO (salen) and the molar ratio of the components used was changed to diphenyl disulfide: VOTPP: Ph ₃ C-BF ₄ = 100: 1: 1. In the same manner as in Example 1, purified PPS was obtained. The obtained purified PPS had a yield of 65%, a melting point = 195 ° C., Mn = 1300, and Mw = 1800.

[Comparative Example 1]
Diphenyl disulfide (5 g) was added to a 50 ml three-necked flask, and vanadyl (IV) acetylacetonate (VO (acac) ₂ ) and triphenylmethyltetrafluoroborate (Ph ₃ C-BF ₄ ) were added at a molar ratio. Diphenyl disulfide: VO (acac) ₂ : Ph ₃ C—BF ₄ = 100: 5: 5 was added. While stirring the inside of the flask with a stirrer chip, it was heated to 100 ° C. in an oil bath, and atmospheric pressure oxygen gas was introduced into the three-necked flask at a flow rate of 10 ml / min. After 20 hours, the oxygen supply was stopped, the oil bath was removed, and the system was cooled to room temperature. The obtained polymer was pulverized, dispersed in 200 ml of dichloromethane, and purified by precipitation with hydrochloric acid acidic methanol. The precipitate was filtered and dried under reduced pressure to obtain purified polyphenylene sulfide (PPS). The obtained purified PPS had a yield of 17% and no melting point.

[Comparative Example 2]
Instead of Ph ₃ C-BF _4, except for using sodium tetraphenylborate _{(NaB (C 6 H 5)} 4) in the same manner as in Comparative Example 1 to obtain a purified polymer. The yield of the purified polymer was 3%, and no melting point was observed.

[Comparative Example 3]
The reaction was conducted in the same manner as in Comparative Example 1 except that VO (salen) was used instead of VO (acac) ₂ . However, no polymer was obtained.

Claims (6)

(A) a vanadium compound, (B) a boron compound represented by the following general formula (I), and (C) a substituted or unsubstituted diphenyl disulfide and / or a substituted or unsubstituted in the presence of an oxidizing agent. A process for producing a polyarylene sulfide, which comprises a step of polymerizing a monomer containing thiophenol under a reaction temperature exceeding 100 ° C.
RBX ₄ (I)
[Wherein, R represents Li, Na, K, Cs, a hydrocarbon group having 1 to 30 carbon atoms, or a silyl group in which three hydrocarbon groups having 1 to 30 carbon atoms are substituted, and X represents a halogen atom. Show. ]   The method for producing polyarylene sulfide according to claim 1, wherein the (A) vanadium compound is an oxo vanadium compound.   The manufacturing method of the polyarylene sulfide of Claim 1 or 2 whose X is a fluorine atom in the said general formula (I).   The manufacturing method of the polyarylene sulfide as described in any one of Claims 1-3 whose said (C) oxidizing agent is the gas containing an oxygen molecule.   5. The poly according to claim 1, wherein the monomer comprises at least one of unsubstituted diphenyl disulfide and unsubstituted thiophenol and at least one of substituted diphenyl disulfide and substituted thiophenol. A process for producing arylene sulfide. The process of polymerizing under conditions where the reaction temperature exceeds 100 ° C is a process of polymerizing while removing by-product water out of the system under conditions where the reaction temperature exceeds 100 ° C. The method for producing polyarylene sulfide according to one item.