JP2014159544A - Method for producing polyarylene sulfide - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a polyarylene sulfide having a higher molecular weight at a low temperature in a short period of time by solving the problem where the conversion of a cyclic polyarylene sulfide into a polyarylene sulfide requires a high temperature and a long time and a polyarylene sulfide of high molecular weight is difficult to be produced.SOLUTION: There is provided a method for producing a polyarylene sulfide in which a cyclic polyarylene sulfide is heated under a degassing condition in the presence of a zero-valent transition metal compound.

Description

  The present invention relates to a method for producing a polyarylene sulfide, and more particularly to a method for producing a polyarylene sulfide characterized by heating a cyclic polyarylene sulfide in the presence of a zero-valent transition metal compound under devolatilization conditions. Is.

  Polyarylene sulfides typified by polyphenylene sulfide (hereinafter sometimes abbreviated as PPS) have excellent heat resistance, barrier properties, chemical resistance, electrical insulation, moist heat resistance, flame resistance, and other suitable properties as engineering plastics. It is resin which has. In addition, it can be molded into various molded parts, films, sheets, fibers, etc. by injection molding and extrusion molding, and widely used in fields requiring heat resistance and chemical resistance, such as various electrical / electronic parts, mechanical parts, and automotive parts. It has been.

  As a specific method for producing this polyarylene sulfide, a method of reacting an alkali metal sulfide such as sodium sulfide with a polyhaloaromatic compound such as p-dichlorobenzene in an organic amide solvent such as N-methyl-2-pyrrolidone. This method is widely used as an industrial production method of polyarylene sulfide. However, this production method requires the reaction to be carried out under high temperature, high pressure, and strong alkaline conditions, and further requires an expensive high-boiling polar solvent such as N-methylpyrrolidone. However, it has a problem that it requires a large amount of process cost.

  On the other hand, as another method for producing polyarylene sulfide, a method for producing polyarylene sulfide by heating cyclic polyarylene sulfide is disclosed. In this method, it can be expected to obtain a polyarylene sulfide having a high molecular weight, a narrow molecular weight distribution, and a small weight loss when heated, but the reaction of the cyclic polyarylene sulfide is completed at a high temperature to complete the reaction. Since it has a long time, a method for producing polyarylene sulfide at a lower temperature and in a shorter time has been desired (for example, Patent Document 1). A polymerization method of polyphenylene sulfide in which a mixture of cyclic polyphenylene sulfide and linear polyphenylene sulfide is heated as a monomer source is also known (Non-Patent Document 1). This method is an easy polymerization method of polyphenylene sulfide, but the polyphenylene sulfide obtained has a low degree of polymerization and is not suitable for practical use. Although this document discloses that the degree of polymerization can be improved by increasing the heating temperature, it still does not reach a molecular weight suitable for practical use, and in this case, the formation of a crosslinked structure is not achieved. It has been pointed out that only polyphenylene sulfide having inferior thermal properties cannot be obtained, and a high-quality polyphenylene sulfide polymerization method more suitable for practical use has been desired.

  In addition, there is known a method of using various catalyst components (a compound having a radical generating ability, an ionic compound, etc.) that promote the conversion when converting cyclic polyarylene sulfide to polyarylene sulfide. Patent Document 2 and Non-Patent Document 2 disclose compounds capable of generating radicals by heating, for example, as compounds having radical generating ability, and specifically, compounds containing disulfide bonds are disclosed. Patent Documents 3 and 4 disclose an ionic compound that can be a ring-opening polymerization catalyst in anionic polymerization, and specifically, an alkali metal salt of sulfur that generates an anionic species such as a sodium salt of thiophenol. A method of using is disclosed. However, even if this method is used, the effect of promoting the conversion of cyclic polyarylene sulfide to polyarylene sulfide is insufficient, and there is a problem that the reaction of cyclic polyarylene sulfide has a high temperature and a long time to complete. was there. Patent Document 3 discloses, as an ionic compound that can be a ring-opening polymerization catalyst in cationic polymerization, a Lewis acid such as iron (III) chloride, a protonic acid, a trialkyloxonium salt, a carbonium salt, a diazonium salt, an ammonium salt, Although a method using an alkylating agent or a silylating agent is also mentioned, there is no specific disclosure regarding the effect of these ring-opening polymerization catalysts, and the effect was not clear. Furthermore, for example, when iron (III) chloride is used as the ring-opening polymerization catalyst, the mechanism of action of the ring-opening polymerization catalyst is not clear, and the method for adding the catalyst to the cyclic polyarylene sulfide and the specific polymerization conditions There was no disclosure.

  Patent Document 5 discloses a method in which an ionic compound that can be a ring-opening polymerization catalyst and a Lewis acid coexist in anionic polymerization, and specifically, a sodium salt of thiophenol and copper (II) chloride coexist. Is disclosed. However, even if this method is used, the effect of promoting the conversion of cyclic polyarylene sulfide to polyarylene sulfide is insufficient, and there is a problem that the reaction of cyclic polyarylene sulfide has a high temperature and a long time to complete. was there.

  Further, Patent Document 6 discloses a method using, for example, tetrakis (triphenylphosphine) palladium as a zero-valent transition metal compound. Although arylene sulfide is obtained, a method for producing polyarylene sulfide having a higher degree of polymerization has been desired in order to further improve the properties such as mechanical strength and chemical resistance of the polyarylene sulfide molded product. Patent Document 7 discloses a method using, for example, iron chloride as a low-valent iron compound, and even when this method is used, polyarylene sulfide can be obtained at a low temperature in a short time. However, a method for producing a polyarylene sulfide having a higher degree of polymerization has been desired.

  As described above, in the conversion of cyclic polyarylene sulfide to polyarylene sulfide by the conventional technique, the promoting effect or the degree of polymerization is not sufficient, and a polyarylene sulfide having a higher degree of polymerization can be obtained at a low temperature in a short time. A method of manufacturing has been desired.

International Publication No. 2007/034800 US Pat. No. 5,869,599 JP-A-5-163349 JP-A-5-105757 Japanese Patent Laid-Open No. 5-301962 International Publication No. 2011-013686 JP 2012-92315 A

Polymer, vol. 37, no. 14, 1996 (3111-3116) Macromolecules, 30, 1997 (pages 4502-4503)

  The present invention solves the above-mentioned problem that it takes a high temperature and a long time to convert a cyclic polyarylene sulfide to a polyarylene sulfide, and it is difficult to increase the degree of polymerization. It is an object of the present invention to provide a production method that can be obtained at a low temperature in a short time.

  The present invention is a method for producing a polyarylene sulfide characterized by heating a cyclic polyarylene sulfide in the presence of a zero-valent transition metal compound under devolatilization conditions.

That is, the present invention is as follows.
(1) A method for producing polyarylene sulfide, comprising heating cyclic polyarylene sulfide in the presence of a zero-valent transition metal compound under devolatilization conditions.
(2) The above-described (1), wherein the zero-valent transition metal compound is a compound in which a ligand is coordinated to a zero-valent transition metal atom without using a ligand-free lone pair. ) For producing a polyarylene sulfide.
(3) The above (1), wherein the zero-valent transition metal compound is a compound in which a ligand is coordinated to a zero-valent transition metal atom via an unsaturated bond site of the ligand (2) The method for producing a polyarylene sulfide according to any one of (2).
(4) The method for producing a polyarylene sulfide as described in any one of (1) to (3) above, wherein the ligand structure constituting the zero-valent transition metal compound does not contain an unshared electron pair. .
(5) The method for producing a polyarylene sulfide according to any one of (1) to (4) above, wherein the ligand constituting the zero-valent transition metal compound is 1,5-cyclooctadiene. .
(6) The method for producing a polyarylene sulfide as described in (1) above, wherein the zero-valent transition metal compound is a compound having no ligand.
(7) The metal constituting the zero-valent transition metal compound is at least one metal selected from metals of Groups 8 to 11 and Periods 4 to 6 of the periodic table. (1) The manufacturing method of the polyarylene sulfide as described in (6).
(8) The method for producing a polyarylene sulfide as described in any one of (1) to (7) above, wherein the zero-valent transition metal compound is a zero-valent nickel compound.

  ADVANTAGE OF THE INVENTION According to this invention, in the heating of cyclic polyarylene sulfide, the manufacturing method of polyarylene sulfide of higher polymerization degree can be provided in low temperature and a short time compared with the conventional method.

  Embodiments of the present invention will be described below.

<Polyarylene sulfide>
The polyarylene sulfide in the present invention is a homopolymer or copolymer having a repeating unit of the formula:-(Ar-S)-as a main constituent unit, preferably containing 80 mol% or more of the repeating unit. Ar includes units represented by the following formulas (A) to (K), among which the formula (A) is particularly preferable.

(R1 and R2 are substituents selected from hydrogen, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an arylene group having 6 to 24 carbon atoms, and a halogen group, and R1 and R2 May be the same or different)

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

  Further, the polyarylene sulfide in the present invention may be any of a random copolymer, a block copolymer and a mixture thereof containing the above repeating unit.

  Typical examples of these include polyphenylene sulfide, polyphenylene sulfide sulfone, polyphenylene sulfide ketone, random copolymers thereof, block copolymers, and mixtures thereof. Particularly preferred polyarylene sulfides include p-phenylene sulfide units as the main structural unit of the polymer.

Is polyphenylene sulfide containing 80 mol% or more, particularly 90 mol% or more.

  The preferred molecular weight of the polyarylene sulfide of the present invention is 10,000 or more in terms of weight average molecular weight, preferably 40,000 or more, more preferably 50,000 or more, still more preferably 60,000 or more, and even more preferably 70,000. As described above, even more preferably 100,000 or more. When the weight average molecular weight is 10,000 or more, the moldability at the time of processing is good, and the properties such as mechanical strength and chemical resistance of the molded product are high. Although there is no restriction | limiting in particular in the upper limit of a weight average molecular weight, Less than 1,000,000 can be illustrated as a preferable range, More preferably, it is less than 500,000, More preferably, it is less than 200,000. Sex can be obtained.

  The polyarylene sulfide obtained by the production method of the present invention tends to have a feature that the molecular weight distribution is broad, that is, the degree of dispersion expressed by the ratio of the weight average molecular weight to the number average molecular weight (weight average molecular weight / number average molecular weight) is narrow. is there. The degree of dispersion of the polyarylene sulfide obtained by the production method of the present invention is preferably 2.5 or less, more preferably 2.3 or less, and even more preferably 2.1 or less. If the degree of dispersion is 2.5 or less, the amount of low-molecular components contained in polyarylene sulfide tends to decrease, which is an improvement in mechanical properties when polyarylene sulfide is used for molding processing, and gas when heated There are effects such as a reduction in the amount generated and a reduction in the amount of the eluted component when in contact with the solvent. In addition, the said weight average molecular weight and number average molecular weight can be calculated | required, for example using SEC (size exclusion chromatography) equipped with the differential refractive index detector.

  The method for producing polyarylene sulfide of the present invention is characterized in that polyarylene sulfide is obtained by heating cyclic polyarylene sulfide in the presence of a zero-valent transition metal compound under devolatilization conditions. The polyarylene sulfide of the present invention having the above-mentioned characteristics can be obtained.

  In the production method of the present invention, the conversion rate of cyclic polyarylene sulfide to polyarylene sulfide is preferably 70% or more, more preferably 80% or more, and further preferably 90% or more. If the conversion is 70% or more, a polyarylene sulfide having the above-described characteristics can be obtained.

The conversion ratio of cyclic polyarylene sulfide to polyarylene sulfide is determined by the amount of cyclic polyarylene sulfide contained in the raw material before heating and the amount of unreacted cyclic polyarylene sulfide contained in the product obtained by heating. Quantitatively using high performance liquid chromatography (HPLC), and can be calculated from the value. In particular,
Conversion rate = (Amount of cyclic polyarylene sulfide contained in raw material before heating−Amount of unreacted cyclic polyarylene sulfide) / Amount of cyclic polyarylene sulfide contained in the raw material before heating .

<Cyclic polyarylene sulfide>
The cyclic polyarylene sulfide in the method for producing a polyarylene sulfide of the present invention is a compound represented by the formula: — (Ar—S) — having a repeating unit as a main constituent unit, preferably the following general formula containing 80 mol% or more of the repeating unit. The cyclic compound such as (O) contains at least 50% by weight, preferably 70% by weight or more, more preferably 80% by weight or more, and still more preferably 90% by weight or more. Ar includes units represented by the above formulas (A) to (K), among which the formula (A) is particularly preferable.

  In the cyclic compound of the formula (O) in the cyclic polyarylene sulfide, repeating units such as the formulas (A) to (K) may be included randomly or in blocks. Any of the mixtures may be used. Typical examples of these include cyclic polyphenylene sulfide, cyclic polyphenylene sulfide sulfone, cyclic polyphenylene sulfide ketone, cyclic random copolymers containing these, cyclic block copolymers, and mixtures thereof. . Particularly preferred cyclic compounds of formula (O) are p-phenylene sulfide units as the main structural unit.

Is a cyclic compound containing 80 mol% or more, particularly 90 mol% or more.

  Although there is no restriction | limiting in particular in the repeating number m in the said (O) formula contained in cyclic polyarylene sulfide, 4-50 are preferable. Here, the lower limit is preferably 4 or more, more preferably 5 or more, still more preferably 6 or more, still more preferably 7 or more, and still more preferably 8 or more. Since cyclic compounds having a small m tend to have low reactivity, it is preferable to set m in the above range from the viewpoint that polyarylene sulfide can be obtained in a short time. On the other hand, the upper limit is preferably 50 or less, more preferably 25 or less, and even more preferably 15 or less. As will be described later, the conversion of the cyclic polyarylene sulfide to the polyarylene sulfide by heating is preferably performed at a temperature equal to or higher than the temperature at which the cyclic polyarylene sulfide is melted. However, when m is increased, the temperature at which the cyclic polyarylene sulfide is melted is increased. It tends to be higher. Therefore, in order to convert the cyclic polyarylene sulfide to the polyarylene sulfide at a lower temperature, it is preferable to set m to the above range.

  The cyclic compound of the formula (O) contained in the cyclic polyarylene sulfide may be either a single compound having a single repeating number or a mixture of cyclic compounds having different repeating numbers, but different repeating numbers. A mixture of cyclic compounds having a tendency to melt at a lower temperature than a single compound having a single number of repetitions, and the use of a mixture of cyclic compounds having different numbers of repetitions may result in conversion to polyarylene sulfide. Since the heating temperature at the time of performing can be made lower, it is preferable.

  It is particularly preferable that the components other than the cyclic compound of the formula (O) in the cyclic polyarylene sulfide are polyarylene sulfide oligomers. Here, the polyarylene sulfide oligomer is a linear homo-oligomer or co-oligomer having a repeating unit of the formula, — (Ar—S) —, as a main constituent unit, preferably containing 80 mol% or more of the repeating unit. . Ar includes units represented by the above formulas (A) to (K), among which the formula (A) is particularly preferable. The polyarylene sulfide oligomer can contain a small amount of branching units or crosslinking units represented by the above formulas (L) to (N) as long as these repeating units are the main structural units. The amount of copolymerization of these branched units or cross-linked units is preferably in the range of 0 to 1 mol% with respect to 1 mol of-(Ar-S)-units. Further, the polyarylene sulfide oligomer may be any of a random copolymer, a block copolymer and a mixture thereof containing the above repeating unit.

  Typical examples of these include polyphenylene sulfide oligomers, polyphenylene sulfide sulfone oligomers, polyphenylene sulfide ketone oligomers, random copolymers, block copolymers, and mixtures thereof. Particularly preferred polyarylene sulfide oligomers include polyphenylene sulfide oligomers containing 80 mol% or more, particularly 90 mol% or more of p-phenylene sulfide units as the main structural unit of the polymer.

  Examples of the molecular weight of the polyarylene sulfide oligomer include those having a molecular weight lower than that of the polyarylene sulfide, and specifically, the weight average molecular weight is preferably less than 10,000.

  The amount of the polyarylene sulfide oligomer contained in the cyclic polyarylene sulfide is particularly preferably smaller than the cyclic compound of the above formula (O) contained in the cyclic polyarylene sulfide. That is, the weight ratio of the cyclic compound (O) to the polyarylene sulfide oligomer in the cyclic polyarylene sulfide (cyclic compound of the formula (O) / polyarylene sulfide oligomer) is preferably more than 1. More preferably 3 or more, more preferably 4 or more, and even more preferably 9 or more. By using such a cyclic polyarylene sulfide, it is possible to easily obtain a polyarylene sulfide having a weight average molecular weight of 10,000 or more. It is. Accordingly, the larger the weight ratio of the cyclic compound of formula (O) to the polyarylene sulfide oligomer in the cyclic polyarylene sulfide, the higher the weight average molecular weight of the polyarylene sulfide obtained by the method for producing polyarylene sulfide of the present invention. Tend to grow. Although there is no particular upper limit to this weight ratio, in order to obtain a cyclic polyarylene sulfide having a weight ratio exceeding 100, it is necessary to significantly reduce the polyarylene sulfide oligomer content in the cyclic polyarylene sulfide. Takes a lot of effort. According to the polyarylene sulfide production method of the present invention, it is possible to easily obtain a polyarylene sulfide having a weight average molecular weight of 10,000 or more even when a cyclic polyarylene sulfide having a weight ratio of 100 or less is used.

The weight ratio of the cyclic compound of the formula (O) and the polyarylene sulfide oligomer in the cyclic polyarylene sulfide is determined from the amount of the cyclic compound of the formula (O) in the cyclic polyarylene sulfide determined by HPLC. Can be calculated. For example, when the component other than the cyclic compound of the formula (O) in the cyclic polyarylene sulfide is a polyarylene sulfide oligomer,
Weight ratio = Amount of cyclic compound of formula (O) (%) / (100−Amount of cyclic compound of formula (O) (%))
It can be calculated as follows.

  The upper limit of the molecular weight of the cyclic polyarylene sulfide used in the production of the polyarylene sulfide of the present invention is preferably 10,000 or less, preferably 5,000 or less, more preferably 3,000 or less, in terms of weight average molecular weight, The lower limit is preferably 300 or more, preferably 400 or more, and more preferably 500 or more in terms of weight average molecular weight.

<Zerovalent transition metal compound>
In the present invention, various zero-valent transition metal compounds are used as a polymerization catalyst. As the zero-valent transition metal compound of the present application, a zero-valent transition metal atom having no ligand or a compound composed of a zero-valent transition metal atom and a ligand is suitable. A compound in which a ligand is coordinated is suitable. Among various transition metal species, from the viewpoint of the effect of promoting the conversion of cyclic polyarylene sulfide to polyarylene sulfide, preferably from Group 8 to Group 11 and Period 4 to Period 6 of the periodic table. At least one selected metal is used. Examples of the metal species include nickel, palladium, platinum, copper, silver, gold, iron, ruthenium, osmium, cobalt, rhodium, and iridium. The reason for this is not clear at this time, but these transition metal atoms, which can take many valence states, are likely to interact with the cyclic polyarylene sulfide structure, or these transition metal atoms are cyclic polyarylene. It is speculated that it is possible to form a transition metal compound that is easily dispersed in sulfide.

  Among these transition metal species, transition metals selected from metals in Group 10 of the periodic table and from the 4th to 6th periods are preferred because they tend to have a high effect of promoting the conversion of the cyclic polyarylene sulfide. Specific examples include nickel, palladium, and platinum. The reason for this is not clear at the present time, but it is presumed that the interaction between the transition metal atom and the cyclic polyarylene sulfide structure tends to be relatively strong due to the electronic states that these transition metal atoms can take.

  Among these transition metal species, nickel that has a tendency to have a particularly high effect of promoting the conversion of cyclic polyarylene sulfide and is excellent in terms of catalyst cost and availability is further preferable. The reason for this is not clear at the present time, but it is presumed that nickel can form a salt or complex that is particularly easily dispersed in the cyclic polyarylene sulfide.

  Zero-valent transition metal compounds are coordinated with zero-valent transition metal atoms that do not have a ligand because they tend to be highly reactive, or because they tend to be highly stable The latter compound is suitable, and in the latter case, a compound in which a ligand is coordinated to a zero-valent transition metal atom is suitable, but after the transition metal compound is added to the cyclic polyarylene sulfide, the compound is uniformly formed. Since it is preferable to disperse, in the compound composed of a zero-valent transition metal atom and a ligand, the ligand is preferably an organic compound having a good affinity for the cyclic polyarylene sulfide. In addition, when the zero-valent transition metal compound is a cationic compound or an anionic compound, it acts as an initiator for cationic polymerization or anionic polymerization, and tends to suppress an increase in the degree of polymerization of the resulting polyarylene sulfide. The zero-valent transition metal compound used in the present invention is preferably neutral. Therefore, in order to form a neutral zero-valent transition metal compound, it is preferable that the ligand also has zero formal charge in the compound composed of the zero-valent transition metal atom and the ligand. Examples of the ligand constituting the transition metal compound include carbene, carbonyl, alkene, alkyne, diene, arene, phosphine, phosphite, amine and the like.

  Examples of the zero-valent transition metal compound of the present invention include nickel (0), palladium (0), platinum (0), iron (0), and ruthenium (0) as zero-valent transition metal atoms having no ligand. , Rhodium (0), tetrakis (triphenylphosphine) nickel, tetrakis (triphenylphosphite) nickel, bis (1,5-cyclooctadiene) nickel, bis ( Dibenzylideneacetone) palladium, tris (dibenzylideneacetone) dipalladium, tetrakis (triphenylphosphine) palladium, bis (tri-t-butylphosphine) palladium, bis [1,2-bis (diphenylphosphino) ethane] palladium, Bis (tricyclohexylphosphine) palladium, [P, P′-1,3 Bis (di-i-propylphosphino) propane] [P-1,3-bis (di-i-propylphosphino) propane] palladium, 1,3-bis (2,6-di-i-propylphenyl) Imidazole-2-ylidene (1,4-naphthoquinone) palladium dimer, 1,3-bis (2,4,6-trimethylphenyl) imidazol-2-ylidene (1,4-naphthoquinone) palladium dimer, bis (3,5,3 ′, 5′-dimethoxydibenzylideneacetone) palladium, bis (tri-t-butylphosphine) platinum, tetrakis (triphenylphosphine) platinum, tetrakis (trifluorophosphine) platinum, ethylenebis (triphenyl) Phosphine) platinum, platinum-2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrashiro Sun complex, dodecamethylene carbonyl ferric, iron pentacarbonyl, triruthenium dodecacarbonyl, dodecacarbonyl four rhodium, such as hexadecanol carbonyl six rhodium can be exemplified.

  Among these, in a compound composed of a zero-valent transition metal atom and a ligand, a zero-valent transition metal compound in which the coordination between the zero-valent transition metal atom and the ligand is not via a lone pair of ligands is used. When the cyclic polyarylene sulfide is heated, the cyclic polyarylene is formed by using a zero-valent transition metal compound in which the coordination between the zero-valent transition metal atom and the ligand is via a lone pair of ligands. Compared to heating of sulfide, it is preferable because the molecular weight of polyarylene sulfide obtained by the method for producing polyarylene sulfide of the present invention tends to be high. The reason for this is not clear at present, but when the coordination between the zero-valent transition metal atom and the ligand is not via the lone pair of ligands, the coordination power tends to be relatively weak, Since the dissociation between the zero-valent transition metal atom and the ligand is easy, vacancies that can interact with the cyclic polyarylene sulfide or polyarylene sulfide are easily generated on the zero-valent transition metal atom, or the zero-valent transition Conversion of cyclic polyarylene sulfide to polyarylene sulfide and polyarylene sulfide are facilitated because the steric hindrance of the metal compound is reduced and the zero-valent transition metal atom and cyclic polyarylene sulfide or polyarylene sulfide are easily accessible. It is believed that further increase in the degree of polymerization is likely to proceed. The coordination between the zero-valent transition metal atom and the ligand not via an unshared electron pair includes, for example, coordination via an unsaturated bond site of the ligand.

  Examples of the ligand capable of forming a zero-valent transition metal compound in which the coordination between the zero-valent transition metal atom and the ligand does not involve the unshared electron pair of the ligand include, for example, alkenes, alkynes, dienes, arenes, carbon dioxide (Coordination by π electrons) can be exemplified.

  Examples of zero-valent transition metal compounds in which the coordination between the zero-valent transition metal atom and the ligand does not involve the lone pair of ligands include bis (1,5-cyclooctadiene) nickel and bis (dibenzylideneacetone). ) Palladium, tris (dibenzylideneacetone) dipalladium, bis (3,5,3 ′, 5′-dimethoxydibenzylideneacetone) palladium and the like.

  Examples of the ligand capable of forming a zero-valent transition metal compound in which the coordination between the zero-valent transition metal atom and the ligand is via the unsaturated bond site of the ligand include alkene, alkyne, diene, arene, dioxide Examples thereof include carbon (coordination by π electrons).

  More specifically, unsubstituted or substituted methylene, acetylene, butadiene, norbornadiene, 1,5-cyclooctadiene, dibenzylideneacetone, indene, fluorene, benzene and the like can be exemplified.

  Examples of zero-valent transition metal compounds in which the coordination between the zero-valent transition metal atom and the ligand is via the unsaturated bond site of the ligand include bis (1,5-cyclooctadiene) nickel and bis (dibenzylidene). Acetone) palladium, tris (dibenzylideneacetone) dipalladium, bis (3,5,3 ′, 5′-dimethoxydibenzylideneacetone) palladium and the like can be exemplified.

  Further, among these, a zero-valent transition metal compound that does not contain an unshared electron pair in the ligand structure is more preferable because the resulting polyarylene sulfide tends to have a higher molecular weight. Although the reason for this is not clear at present, a ligand having an unshared electron pair in a zero-valent transition metal compound or a ligand having an unshared electron pair dissociated from a zero-valent transition metal atom is an unshared electron. Since it interacts with cyclic polyarylene sulfide or polyarylene sulfide via a pair, it is presumed that there is a tendency to stabilize the structure of cyclic polyarylene sulfide or polyarylene sulfide. By not including an unshared electron pair in the ligand structure, stabilization of the cyclic polyarylene sulfide structure or polyarylene sulfide structure by the ligand dissociated from the zero-valent transition metal atom does not occur, and the cyclic polyarylene It is believed that conversion from sulfide to polyarylene sulfide and further higher degree of polymerization of polyarylene sulfide are likely to proceed.

  Examples of the ligand that does not include an unshared electron pair in the ligand structure include alkene, alkyne, diene, and arene that do not have a substituent that includes an unshared electron pair.

  More specifically, methylene, acetylene, butadiene, norbornadiene, 1,5-cyclooctadiene, indene, fluorene, benzene, etc., which are unsubstituted or substituted but do not have a substituent containing an unshared electron pair Can be illustrated.

  Examples of the zero-valent transition metal compound that does not include an unshared electron pair in the ligand structure include bis (1,5-cyclooctadiene) nickel.

  The ligand may be a monodentate ligand or a polydentate ligand. The coordination force between the transition metal atom and the ligand tends to be relatively weak for monodentate ligands and relatively strong for multidentate ligands. Therefore, monodentate ligands tend to have a high effect of promoting the conversion of cyclic polyarylene sulfides to polyarylene sulfides, and multidentate ligands tend to have high stability of zero-valent transition metal compounds. It can be selected according to the polyarylene sulfide production method to be carried out and the desired effect.

  Coordination power between zero-valent transition metal atoms and ligands, and the removal effect of ligands by devolatilization, which will be described later, are atomic species coordinated with zero-valent transition metal atoms, monodentate coordination, multidentate coordination, etc. It differs depending on the coordination form, ligand sublimation characteristics and devolatilization conditions, etc., but it cannot be defined uniformly. However, from the viewpoint of easy dissociation of the zero-valent transition metal atom and the ligand, From the viewpoint that the ligand is volatilized and removed from the arylene sulfide so that the effect of stabilizing the cyclic polyarylene sulfide structure by the ligand does not occur, the boiling point at normal pressure of the ligand is 400 ° C. or less. It is preferable that it is preferably 300 ° C. or lower, and more preferably 200 ° C. or lower. For the same reason, the melting point of the ligand at normal pressure is preferably 200 ° C. or lower, more preferably 150 ° C. or lower, further preferably 100 ° C. or lower, and 50 ° C. or lower. Is even more preferred.

  In the present invention, the cyclic polyarylene sulfide is heated in the presence of a zero-valent transition metal compound. The zero-valent transition metal compound may be added as a raw material, or the zero-valent transition metal compound may be added in the system. It may be generated. Moreover, you may use individually by 1 type and may use 2 or more types together. Here, in order to produce a zero-valent transition metal compound in the system as in the latter case, a transition metal salt and the above-mentioned ligand are added, or a transition metal salt and a reducing agent described later are added, or a transition metal salt And a ligand and a reducing agent are added to form a zero-valent transition metal compound in the system, and a complex composed of a transition metal salt and the above-described ligand is added to the system. And a method of producing a valent transition metal compound. Here, when adding the complex comprised with the transition metal salt and the ligand mentioned above, you may add the ligand mentioned above and the reducing agent mentioned later further.

  The transition metal salt for generating a zero-valent transition metal compound in the system may be any one that can be dispersed in a cyclic polyarylene sulfide to the extent that it can interact with a ligand, a reducing agent, etc. Examples thereof include acetates and halides of various transition metals. Examples of the transition metal salt include nickel, palladium, platinum, iron, ruthenium, rhodium, copper, silver, gold acetate, halide and the like. Specifically, nickel acetate, nickel chloride, nickel bromide. , Nickel iodide, nickel sulfide, palladium acetate, palladium chloride, palladium bromide, palladium iodide, palladium sulfide, platinum chloride, platinum bromide, iron acetate, iron chloride, iron bromide, iron iodide, ruthenium acetate, chloride Examples include ruthenium, ruthenium bromide, rhodium acetate, rhodium chloride, rhodium bromide, copper acetate, copper chloride, copper bromide, silver acetate, silver chloride, silver bromide, gold acetate, gold chloride, and gold bromide. As the ligand, the various ligands described above are preferably used.

  Examples of the complex composed of the transition metal salt and the above-mentioned ligand include complexes composed of various transition metal salts as described above and the above-mentioned ligands. Specifically, bis (triphenyl Phosphine) nickel dichloride, [1,2-bis (diphenylphosphino) ethane] nickel dichloride, [1,1′-bis (diphenylphosphino) ferrocene] nickel dichloride, nickel bromide ethylene glycol dimethyl ether complex, bis (triphenyl) Phosphine) palladium diacetate, bis (triphenylphosphine) palladium dichloride, [1,2-bis (diphenylphosphino) ethane] palladium dichloride, [1,1′-bis (diphenylphosphino) ferrocene] palladium dichloride, dichloro (1,5'-cyclooctadie ) Palladium, bis (ethylenediamine) palladium dichloride, dichloro (1,5'- cyclooctadiene) platinum can be exemplified.

  These may be used alone or in combination of two or more.

  The reducing agent is not particularly limited as long as it produces a zero-valent transition metal compound from the transition metal salt, a complex composed of the transition metal salt and the above-mentioned ligand, but various organic and inorganic reductions. Preferred compounds are, for example, zinc, alkylaluminum compounds, alkali metal hydrides, alkali metal hydrides, alkali metal borohydrides, copper (I) halides, tin (II) halides, halogenated halides. Examples include titanium (III), hydrogen halide compounds, hydrazine compounds, and the like. Of these, zinc, alkylaluminum compounds, alkali metal hydrides, alkali metal hydrides, alkali metal borohydrides are preferred reductions from the viewpoint of reducing ability or handleability for forming zero-valent transition metal compounds. It can be illustrated as an agent. These reducing agents may be used alone or in combination of two or more.

  The valence state of the transition metal atom, the coordination state of the transition metal atom and the ligand, and the binding state of the transition metal atom and the counter ion in the transition metal salt are, for example, X-ray absorption fine structure (XAFS) analysis, X-ray photoelectron spectroscopy It can be grasped by (XPS) analysis. X-ray absorption fine structure analysis is performed by irradiating a zero-valent transition metal compound or a cyclic polyarylene sulfide containing a transition metal compound or a polyarylene sulfide containing a transition metal compound used as a catalyst in the present invention with X-rays. Then, by comparing the absorption spectra, X-ray photoelectron spectroscopy can be grasped by observing the kinetic energy of photoelectrons emitted from the sample surface.

  In the X-ray absorption fine structure (XAFS) analysis, for example, when evaluating the valence state of a nickel compound, it is effective to compare the absorption spectra related to the K-edge X-ray absorption near-edge structure (XANES), and the spectrum rises. A determination can be made by comparing energy and spectral shape. For example, in contrast to a spectrum obtained by measuring a divalent nickel compound, a spectrum obtained by measuring a zero-valent nickel compound tends to increase the intensity of the pre-edge region near 8330 eV.

  In X-ray photoelectron spectroscopy (XPS) analysis, information on the binding energy of bound electrons in a substance can be obtained by measuring the kinetic energy of photoelectrons. From this binding energy value, surface element information and each peak can be obtained. It is possible to obtain information on the valence and bonding state from the energy shift. Therefore, for example, when evaluating the valence state of a nickel compound, it is effective to compare peak energy shifts. For example, the peak obtained by measuring the zero-valent nickel compound tends to be on the lower energy side with respect to the peak obtained by measuring the II-valent nickel compound.

  The concentration of the zero-valent transition metal compound to be used varies depending on the molecular weight of the target polyarylene sulfide and the type of the polymerization catalyst, but is usually 0.001 to 20 mol% with respect to the sulfur atom in the cyclic polyarylene sulfide. Preferably it is 0.005-15 mol%, More preferably, it is 0.01-10 mol%. If it is 0.001 mol% or more, the cyclic polyarylene sulfide is sufficiently converted to polyarylene sulfide, and if it is 20 mol% or less, a polyarylene sulfide having the above-described properties can be obtained. The concentration of the zero-valent transition metal compound here refers to the concentration when the zero-valent transition metal compound is added as a raw material. On the other hand, when a zero-valent transition metal is generated in the system, it refers to the concentration of a transition metal salt added as a raw material or a complex composed of a transition metal salt and a ligand.

  When adding the zero-valent transition metal compound, transition metal salt, complex composed of transition metal salt and ligand, ligand, or reducing agent, it may be added as it is, but in the cyclic polyarylene sulfide. It is preferable to disperse uniformly. Examples of a uniform dispersion method include a mechanical dispersion method, a dispersion method using a solvent, a method of melting and dispersing a cyclic polyarylene sulfide, a polymerization reaction apparatus, a mold for manufacturing a molded product, an extruder, Examples thereof include a method of dispersing in an apparatus such as a melt kneader, or a method of dispersing on a fibrous material in advance when the fibrous material coexists when the cyclic polyarylene sulfide is heated.

  Specific examples of the mechanical dispersion method include a pulverizer, a stirrer, a mixer, a shaker, and a method using a mortar.

  As a method of dispersing using a solvent, specifically, cyclic polyarylene sulfide is dissolved or dispersed in an appropriate solvent, and this is composed of a zero-valent transition metal compound, a transition metal salt, a transition metal salt and a ligand. Examples of the method include removing a solvent after adding a predetermined amount of a complex, a ligand, or a reducing agent.

  As a method for melting and dispersing the cyclic polyarylene sulfide, the solid polycyclic arylene sulfide is a zero-valent transition metal compound, a transition metal salt, a complex composed of a transition metal salt and a ligand, a ligand, Alternatively, a method of melting cyclic polyarylene sulfide by heating after adding a reducing agent, consisting of zero-valent transition metal compound, transition metal salt, transition metal salt and ligand after previously melting cyclic polyarylene sulfide. And a method of adding a complex, a ligand, or a reducing agent.

  As a method of dispersing in advance in a polymerization reaction apparatus, a mold for producing a molded product, an apparatus such as an extruder or a melt kneader, a method of dispersing as it is, a zero-valent transition metal compound, a transition metal salt, a transition metal in an appropriate solvent After adding a predetermined amount of a complex composed of a salt and a ligand, a ligand, or a reducing agent, the solvent is removed in a polymerization reaction apparatus, a mold for producing a molded article, an apparatus such as an extruder or a melt kneader. A method of dispersing by doing so can be exemplified.

  As a method of dispersing on a fibrous material in advance, a method of dispersing as it is, a zero-valent transition metal compound, a transition metal salt, a complex composed of a transition metal salt and a ligand, a ligand, or a reduction in an appropriate solvent Examples thereof include a method in which a predetermined amount of an agent is added, and then applied to a fibrous material, dispersed or impregnated, and then dispersed by removing the solvent.

  In addition, when two or more compounds are added, depending on the stability and reactivity of the compound to be added, they may be added at once, or after being added separately, the polymerization reaction apparatus and the molded product are added. You may mix inside and outside apparatuses, such as a type | mold to manufacture, an extruder, and a melt kneader.

  In addition, when the zero-valent transition metal compound, transition metal salt, complex composed of a transition metal salt and a ligand, a ligand, or a reducing agent is a solid, more uniform dispersion is possible. The average particle size is preferably 1 mm or less.

  It is also preferable to add them under a non-oxidizing atmosphere according to the stability of the ligand species, the zero-valent transition metal compound, the transition metal salt, the complex composed of the transition metal salt and the ligand, or the reducing agent. . Non-oxidizing atmosphere means cyclic polyarylene sulfide, zero-valent transition metal compound, transition metal salt, complex composed of transition metal salt and ligand, or oxygen concentration in the gas phase in contact with the reducing agent is 5% by volume or less , Preferably 2% by volume or less, more preferably an atmosphere substantially free of oxygen, that is, an inert gas atmosphere such as nitrogen, helium, argon, etc. Among them, particularly in terms of economy and ease of handling Is preferably a nitrogen atmosphere.

<Production conditions for polyarylene sulfide>
The heating temperature for producing the polyarylene sulfide in the present invention is preferably a temperature at which the cyclic polyarylene sulfide is melted, and there is no particular limitation as long as it is such a temperature condition. However, when the heating temperature is lower than the temperature at which the cyclic polyarylene sulfide is melted, a long time tends to be required to obtain the polyarylene sulfide. The temperature at which the cyclic polyarylene sulfide melts varies depending on the composition and molecular weight of the cyclic polyarylene sulfide and the environment during heating. It is possible to grasp by analyzing with a differential scanning calorimeter. However, in general, the melting temperature has a range, and the endotherm accompanying melting tends to continue even when the melting point is exceeded, so that the heating temperature may be equal to or higher than the melting point of the cyclic polyarylene sulfide. Preferably, the temperature is 10 ° C. or more higher than the melting point of the cyclic polyarylene sulfide, and more preferably 20 ° C. or more. The melting point can be measured with a differential scanning calorimeter.

  As a minimum of heating temperature, 180 ° C or more can be illustrated, preferably 200 ° C or more, more preferably 220 ° C or more, still more preferably 240 ° C or more. In this temperature range, the cyclic polyarylene sulfide is melted, the zero-valent transition metal atom and the ligand are dissociated, and the ligand can be easily removed by devolatilization. Can be obtained. On the other hand, if the temperature is too high, undesirable side reactions such as crosslinking reactions and decomposition reactions between cyclic polyarylene sulfides, between polyarylene sulfides produced by heating, and between polyarylene sulfides and cyclic polyarylene sulfides, etc. Therefore, it is desirable to avoid a temperature at which such undesirable side reactions are remarkably caused, since the characteristics of the resulting polyarylene sulfide may be deteriorated. As an upper limit of heating temperature, 400 degrees C or less can be illustrated. Below this temperature, adverse effects on the properties of the resulting polyarylene sulfide due to undesirable side reactions tend to be suppressed, and a polyarylene sulfide having the above-described properties can be obtained. Further, the heating temperature is preferably lower because the energy required for heating or cooling can be reduced and the time can be shortened to improve productivity. From this, a preferable heating temperature is 400 ° C. or lower, more preferably 360 ° C. or lower, more preferably 320 ° C. or lower, and still more preferably 300 ° C. or lower.

  The cyclic polyarylene sulfide is heated under devolatilization conditions. The devolatilization condition is a condition for removing a gaseous component generated when the cyclic polyarylene sulfide is heated in the presence of a zero-valent transition metal compound from the heating system. The components in the gaseous state vary depending on the characteristics of each compound and the details of the devolatilization conditions, and the occurrence and level of the components vary. For example, a ligand contained in a zero-valent transition metal compound or a zero-valent transition in the system Counter ion decomposition products contained in transition metal salts added when forming metal compounds, ligands contained in complexes composed of transition metal salts and ligands, decomposition products of counter ions, etc. The polyarylene sulfide oligomer etc. which a formula polyarylene sulfide contains can be illustrated. Among them, the devolatilization condition in the present invention is to remove a ligand contained in the zero-valent transition metal compound, which is generated when the cyclic polyarylene sulfide is heated in the presence of the zero-valent transition metal compound, from the heating system. The conditions are preferable. The condition is not particularly limited as long as the generated gaseous component can be removed from the heating system. For example, devolatilization under continuous decompression conditions, or gas continuously flows into the system. In addition to the inflowing gas, conditions for causing the generated gaseous component to flow out of the heating system, conditions for cooling the generated gaseous state component to be collected outside the system, and the like can be given. By heating under devolatilization conditions, the dissociation between the zero-valent transition metal atom and the ligand is facilitated, so that the interaction between the zero-valent transition metal atom and the cyclic polyarylene sulfide is likely to occur, at a low temperature and in a short time. Polyarylene sulfide can be obtained. On the other hand, when devolatilization is not performed, conversion of cyclic polyarylene sulfide to polyarylene sulfide requires a high temperature and a long time. In addition, since the polyarylene sulfide oligomer and the dissociated ligand are likely to remain in the heating system and cause a side reaction, the degree of polymerization is insufficient.

  In the devolatilization under continuous decompression conditions, the continuous decompression condition is not limited as long as the generated gaseous components can be removed from the heating system. For example, the entire system in which the reaction is performed is continuously decompressed. In the case of heating using a mold for manufacturing a molded article, an extruder, a melt kneader, or the like, from inside a mold under an ordinary pressure or pressurized condition, in an extruder, in a melt kneader, etc. A part may be connected to a decompression device and continuously decompressed. However, even if, for example, the inside of the polymerization system is sealed and heated under reduced pressure, the effect is insufficient, and it is necessary to be under devolatilizing conditions where the pressure is continuously reduced. By performing devolatilization under reduced pressure continuously, the concentration of the ligand in the melted raw material is reduced, and the zero-valent transition metal atom and the ligand are dissociated more efficiently, and from within the heating system of the dissociated ligand. And removal of the polyarylene sulfide oligomer contained in the cyclic polyarylene sulfide from the heating system makes it possible to obtain a polyarylene sulfide having a high degree of polymerization at a lower temperature and in a shorter time.

  The decompression condition means a pressure lower than the atmospheric pressure, and there is no limitation as long as the generated gaseous component can be removed, but in order to remove the generated gaseous component more efficiently. Usually, the upper limit is preferably 50 kPa or less, more preferably 20 kPa or less, and even more preferably 10 kPa or less. An example of the lower limit is 0.1 kPa or more, and 0.2 kPa or more is more preferable. When the decompression condition is at least the preferred lower limit, the cyclic compound having the low molecular weight contained in the cyclic polyarylene sulfide (O) is difficult to volatilize, while below the preferred upper limit, a sufficient devolatilizing effect is obtained. A polyarylene sulfide having the above characteristics can be obtained. By setting the pressure within the above preferred range, it becomes easy to dissociate the zero-valent transition metal atom and the ligand and to remove the polyarylene sulfide oligomer and the dissociated ligand from the heating system at a low temperature for a short time. Therefore, polyarylene sulfide having a higher degree of polymerization tends to be obtained.

  Further, when the pressure is continuously reduced, it is preferable that the atmosphere in the reaction system is once reduced to a non-oxidizing atmosphere. As a result, undesirable side reactions such as cross-linking reaction and decomposition reaction occur between cyclic polyarylene sulfides, between polyarylene sulfides generated by heating, and between polyarylene sulfides and cyclic polyarylene sulfides, and zero-valent transition metals. It tends to be able to suppress the deactivation of the compound. Note that the non-oxidizing atmosphere is an atmosphere in which the oxygen concentration in the gas phase in contact with the cyclic polyarylene sulfide is 5% by volume or less, preferably 2% by volume or less, and more preferably contains substantially no oxygen, that is, nitrogen, helium, This indicates an atmosphere of an inert gas such as argon. Among these, a nitrogen atmosphere is particularly preferable from the viewpoints of economy and ease of handling.

  Under conditions where the gas is continuously flowed into the system and the generated gaseous components are flown out of the heating system together with the gas that has flowed in, the atmosphere in the reaction system is preferably a non-oxidizing atmosphere. As a result, undesirable side reactions such as cross-linking reactions and decomposition reactions can be suppressed between cyclic polyarylene sulfides, between polyarylene sulfides produced by heating, and between polyarylene sulfides and cyclic polyarylene sulfides. It tends to be able to suppress the deactivation of the transition metal compound. The gas to be used is preferably an inert gas such as nitrogen, helium, or argon. Among them, nitrogen gas is particularly preferable from the viewpoints of economy and ease of handling.

  Although the temperature of the gas flowing into the system depends on the flow rate of the flowing gas, the heating temperature in the system, and the structure of the reaction system, there is no particular limitation as long as the heating temperature in the system can be stably controlled. However, from the viewpoint of stable gas temperature control, it is preferably 0 ° C. or higher, more preferably 20 ° C. or higher, further preferably 50 ° C. or higher, from the viewpoint of stable heating temperature control in the system. Is more preferably 100 ° C. or higher, more preferably 150 ° C. or higher, further preferably 180 ° C. or higher, and an even more preferable range is the same temperature as the heating temperature in the system. it can.

  The flow rate of the gas flowing into the system depends on the temperature of the flowing gas, the heating temperature in the system, and the structure of the reaction system, but when the cyclic polyarylene sulfide is heated in the presence of a zero-valent transition metal compound. There is no particular limitation as long as the gaseous component generated in the system can be removed from the heating system and the heating temperature in the system can be stably controlled. However, in terms of the effect of removing the gaseous component generated when the cyclic polyarylene sulfide is heated in the presence of the zero-valent transition metal compound from the heating system, the gas flowing into the system in one minute The flow rate is preferably 1% or more of the volume in the system, more preferably 5% or more, still more preferably 10% or more, and even more preferably 20% or more. it can.

  The amount of ligand removed from the heating system by devolatilization varies depending on the type, amount, heating conditions, devolatilization method and equipment of the zero-valent transition metal compound to be used. It is preferably 20% by weight or more of the ligand added to the polyarylene sulfide, more preferably 40% by weight or more, further preferably 60% by weight or more, and more preferably 80% or more. Even more preferable. Within this range, the zero-valent transition metal atom interacts with the cyclic polyarylene sulfide, and a polyarylene sulfide having a high degree of polymerization can be obtained at a low temperature in a short time.

  The removal amount of the gaseous component generated by devolatilization from the heating system is a method of collecting and weighing the component removed outside the heating system, a method of calculating from the weight difference before and after heating, and the obtained polyarylene sulfide. It can be grasped by a method of calculating and subtracting the amount of the remaining component by reducing the weight during heating.

  The removal amount of the ligand by devolatilization is the same as the heating conditions and the cyclic polyarylene sulfide in the absence of the zero-valent transition metal compound from the removal amount of the gaseous component generated by devolatilization from the heating system. This can be grasped by subtracting the amount of the gaseous component generated when heated under the devolatilization condition from the heating system.

  The reaction time is such as the content of the cyclic compound of the formula (O) in the cyclic polyarylene sulfide to be used, the number of repetitions m, the molecular weight and other characteristics, the type of polymerization catalyst used, the heating temperature, etc. Since it differs depending on the conditions, it cannot be uniformly defined, but it is preferable to set so that the above-mentioned undesirable side reaction does not occur as much as possible. Examples of the heating time include 0.01 to 100 hours, preferably 0.05 to 20 hours, and more preferably 0.05 to 10 hours. According to the preferred production method of the present invention, the cyclic polyarylene sulfide can be heated in 2 hours or less. Examples of the heating time include 2 hours or less, 1 hour or less, 0.5 hours or less, 0.3 hours or less, and 0.2 hours or less. At 0.01 hours or longer, the cyclic polyarylene sulfide is sufficiently converted to polyarylene sulfide, and at 100 hours or shorter, adverse effects on the properties of the resulting polyarylene sulfide due to undesirable side reactions tend to be suppressed.

  The heating of the cyclic polyarylene sulfide can also be performed under conditions substantially free of a solvent. When carried out under such conditions, the temperature can be raised in a short time, the reaction rate is high, and polyarylene sulfide tends to be easily obtained in a short time. Here, the substantially solvent-free condition means that the solvent in the cyclic polyarylene sulfide is 10% by weight or less, and more preferably 3% by weight or less.

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

  The above-described heating of the cyclic polyarylene sulfide can be performed in the presence of a fibrous substance. Here, the fibrous substance is a thin thread-like substance, and an arbitrary substance having a structure elongated like a natural fiber is preferable. By converting the cyclic polyarylene sulfide to the polyarylene sulfide in the presence of the fibrous substance, a composite material structure composed of the polyarylene sulfide and the fibrous substance can be easily prepared. Since such a structure is reinforced by a fibrous substance, it tends to be superior in mechanical properties, for example, as compared to the case of polyarylene sulfide alone.

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

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

  The conversion of the cyclic polyarylene sulfide to the polyarylene sulfide can be performed in the presence of a filler. Examples of the filler include non-fibrous glass, non-fibrous carbon, and inorganic fillers such as calcium carbonate, titanium oxide, and alumina.

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

<Measurement of molecular weight>
The molecular weights of polyarylene sulfide and cyclic polyarylene sulfide are determined by gel permeation chromatography (GPC), which is a type of size exclusion chromatography (SEC), as a number average molecular weight (Mn) and a weight average molecular weight (Mw) in terms of polystyrene. Calculated. The measurement conditions for GPC are shown below.
Equipment: Senshu Science SSC-7110
Column name: Shodex UT806M × 2
Eluent: 1-chloronaphthalene detector: differential refractive index detector Column temperature: 210 ° C
Pre-constant temperature: 250 ° C
Pump bath temperature: 50 ° C
Detector temperature: 210 ° C
Flow rate: 1.0 mL / min
Sample injection amount: 300 μL (slurry: about 0.2% by weight).

<Measurement of conversion>
Calculation of the conversion rate of cyclic polyphenylene sulfide to polyphenylene sulfide was performed by high performance liquid chromatography (HPLC) by the following method.

About 10 mg of the product obtained by heating the cyclic polyarylene sulfide was dissolved in about 5 g of 1-chloronaphthalene at 250 ° C. A precipitate formed upon cooling to room temperature. The 1-chloronaphthalene insoluble component was filtered using a membrane filter having a pore size of 0.45 μm to obtain a 1-chloronaphthalene soluble component. The amount of unreacted cyclic polyarylene sulfide was quantified by HPLC measurement of the obtained soluble component, and the conversion rate of cyclic polyarylene sulfide to polyarylene sulfide was calculated. The measurement conditions for HPLC are shown below.
Apparatus: Shimadzu Corporation LC-10Avp series Column: Mightysil RP-18 GP150-4.6 (5 μm)
Detector: Photodiode array detector (UV = 270 nm).

<X-ray absorption fine structure analysis (XAFS)>
The X-ray absorption fine structure of the nickel compound was measured under the following conditions.
Experimental facility: High Energy Accelerator Research Organization Synchrotron Radiation Research Facility Spectrometer: Si (111) 2 crystal spectrometer Mirror: Condenser mirror Absorption edge: Ni K (8332eV) Absorption edge detection method: Detection using transmission method and fluorescence yield method Instrument: Ion chamber and Lytle detector

<X-ray photoelectron spectroscopy (XPS)>
The X-ray photoelectron spectroscopic analysis of the nickel compound was performed under the following conditions.
Apparatus: Quantera SXM (manufactured by PHI)
Excitation X-ray: monochromic Al K 1,2 line (1486.6 eV)
X-ray diameter: 200m
Photoelectron escape angle (inclination of detector relative to sample surface): 45 °.

Reference Example 1 (Preparation of cyclic polyarylene sulfide)
A stainless steel autoclave equipped with a stirrer was charged with 28.06 g (0.240 mol) of a 48 wt% aqueous solution of sodium hydrosulfide and 25.00 g (0.288 mol) of a 48 wt% aqueous solution prepared using 96% sodium hydroxide. ), 615.0 g (6.20 mol) of N-methyl-2-pyrrolidone (NMP), and 36.16 g (0.246 mol) of p-dichlorobenzene (p-DCB). The reaction vessel was sufficiently purged with nitrogen, and then sealed under nitrogen gas.

  While stirring at 400 rpm, the temperature was raised from room temperature to 200 ° C. over about 1 hour. Next, the temperature was raised from 200 ° C. to 250 ° C. over about 30 minutes. After maintaining at 250 ° C. for 2 hours, the contents were recovered after quenching to near room temperature.

  As a result of analyzing the obtained contents by gas chromatography and high performance liquid chromatography, the consumption rate of monomer p-DCB was 96%, and it was assumed that all sulfur components in the reaction mixture were converted to cyclic PPS. The formula PPS production rate was found to be 16%.

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

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

  After removing the solvent from the extract obtained by the chloroform extraction operation, about 5 g of chloroform was added to prepare a slurry, which was added dropwise to about 600 g of methanol with stirring. The precipitate thus obtained was collected by filtration and vacuum dried at 70 ° C. for 5 hours to obtain a white powder. This white powder was confirmed to be a compound composed of phenylene sulfide units from an absorption spectrum in infrared spectroscopic analysis. Moreover, this white powder has p-phenylene sulfide unit as the main constituent unit based on the mass spectrum analysis of the component divided by high performance liquid chromatography (apparatus; M-1200H manufactured by Hitachi) and molecular weight information by MALDI-TOF-MS. It was found to be a cyclic polyphenylene sulfide containing about 96% by weight of a cyclic compound having 4 to 13 repeating units and suitable for use in the production of the polyarylene sulfide of the present invention. As a result of GPC measurement, the cyclic polyphenylene sulfide was completely dissolved in 1-chloronaphthalene at room temperature, and the weight average molecular weight was 900.

Example 1
To the cyclic polyphenylene sulfide obtained in Reference Example 1, bis (1,5-cyclooctadiene) nickel (described as Ni (cod) _{2 in the} table, the same applies hereinafter) with respect to the sulfur atom in the cyclic polyphenylene sulfide. 100 mg of powder mixed with 1 mol% was charged into a glass ampule, the inside of the ampule was replaced with nitrogen, and then the pressure was reduced to about 0.4 kPa using a vacuum pump. About 10 seconds after the pressure was reduced to about 0.4 kPa, the ampule was placed in an electric furnace whose temperature was adjusted to 300 ° C., and the ampule was heated to about 0.4 kPa with a vacuum pump and heated for 10 minutes while devolatilizing. Thereafter, the ampule was taken out and cooled to room temperature to obtain a black solid. From the absorption spectrum in the solid infrared spectroscopic analysis, it was confirmed that the solid was a compound (PPS) composed of phenylene sulfide units. The solid was partially insoluble in 1-chloronaphthalene at 250 ° C., but it was found that the insoluble part was not a compound having a phenylene sulfide structure but a nickel compound, and the produced PPS component was soluble. As a result of HPLC measurement, it was found that the conversion of cyclic polyphenylene sulfide to PPS was 49%.

  As a result of GPC measurement, a peak derived from cyclic polyphenylene sulfide and a peak of the produced polymer (PPS) were confirmed, and it was found that the obtained PPS had a weight average molecular weight of 110,000 and a dispersity of 2.1. . The results are shown in Table 1.

  In addition, when the ampoule was installed in an electric furnace adjusted to 300 ° C. while devolatilizing while keeping the glass ampoule at about 0.4 kPa, the ampoule temperature was measured separately. It was found that the temperature reached 260 ° C. about 3 minutes after the installation, reached 290 ° C. after about 4 minutes, and stabilized at 300 ° C. after about 5 minutes.

Comparative Example 1
100 mg of powder obtained by mixing 1 mol% of bis (1,5-cyclooctadiene) nickel with respect to the sulfur atom in the cyclic polyphenylene sulfide to the cyclic polyphenylene sulfide obtained in Reference Example 1 was charged into a glass ampule. The inside of the ampoule was replaced with nitrogen. The ampule was placed in an electric furnace adjusted to 300 ° C. and heated for 10 minutes while keeping the inside of the ampule in a normal-pressure nitrogen atmosphere, and then the ampule was taken out and cooled to room temperature to obtain a black solid. From the absorption spectrum in the solid infrared spectroscopic analysis, it was confirmed that the solid was a compound (PPS) composed of phenylene sulfide units. The solid was partially insoluble in 1-chloronaphthalene at 250 ° C., but it was found that the insoluble part was not a compound having a phenylene sulfide structure but a nickel compound, and the produced PPS component was soluble. As a result of HPLC measurement, it was found that the conversion of cyclic polyphenylene sulfide to PPS was 10%. The results are shown in Table 1.

  From the comparison between Example 1 and Comparative Example 1, it was found that the cyclic polyphenylene sulfide was heated in the presence of bis (1,5-cyclooctadiene) nickel, which is a zero-valent transition metal compound, under devolatilization conditions for a shorter time. It was found that the conversion of cyclic polyphenylene sulfide to polyphenylene sulfide proceeds.

  From the comparison between Example 1 and Comparative Example 3, the cyclic polyphenylene sulfide was heated under devolatilization conditions in the presence of bis (1,5-cyclooctadiene) nickel, which is a zero-valent transition metal compound. It was found that the conversion of sulfide to polyphenylene sulfide proceeds. It was also found that polyphenylene sulfide having a higher degree of polymerization can be obtained.

Example 2
A black solid was obtained by performing the same operation as in Example 1 except that the heating time was changed to 60 minutes. From the absorption spectrum in the solid infrared spectroscopic analysis, it was confirmed that the solid was a compound (PPS) composed of phenylene sulfide units. The solid was partially insoluble in 1-chloronaphthalene at 250 ° C., but it was found that the insoluble part was not a compound having a phenylene sulfide structure but a nickel compound, and the produced PPS component was soluble. As a result of HPLC measurement, it was found that the conversion of cyclic polyphenylene sulfide to PPS was 78%.

  As a result of GPC measurement, a peak derived from cyclic polyphenylene sulfide and a peak of the produced polymer (PPS) were confirmed, and it was found that the obtained PPS had a weight average molecular weight of 130,000 and a dispersity of 2.1. . The results are shown in Table 1.

Comparative Example 2
A black solid was obtained by performing the same operation as in Comparative Example 1 except that the heating time was changed to 60 minutes. From the absorption spectrum in the solid infrared spectroscopic analysis, it was confirmed that the solid was a compound (PPS) composed of phenylene sulfide units. The solid was partially insoluble in 1-chloronaphthalene at 250 ° C., but it was found that the insoluble part was not a compound having a phenylene sulfide structure but a nickel compound, and the produced PPS component was soluble. As a result of HPLC measurement, it was found that the conversion of cyclic polyphenylene sulfide to PPS was 58%. The results are shown in Table 1.

Comparative Example 3
100 mg of the cyclic polyphenylene sulfide obtained in Reference Example 1 was charged into a glass ampule, the inside of the ampule was replaced with nitrogen, and then the pressure was reduced to about 0.4 kPa using a vacuum pump. About 10 seconds after the pressure was reduced to about 0.4 kPa, the ampule was placed in an electric furnace whose temperature was adjusted to 300 ° C., and the inside of the ampule was kept at about 0.4 kPa with a vacuum pump and heated for 60 minutes while devolatilizing. Thereafter, the ampule was taken out and cooled to room temperature to obtain a brown solid. From the absorption spectrum in the solid infrared spectroscopic analysis, it was confirmed that the solid was a compound (PPS) composed of phenylene sulfide units. The solid was completely dissolved in 1-chloronaphthalene at 250 ° C. As a result of HPLC measurement, it was found that the conversion of cyclic polyphenylene sulfide to PPS was 35%.

  As a result of GPC measurement, a peak derived from cyclic polyphenylene sulfide and a peak of the produced polymer (PPS) can be confirmed, and the obtained PPS has a weight average molecular weight of 76,000 and a dispersity of 1.9. all right. The results are shown in Table 1.

Comparative Example 4
100 mg of the cyclic polyphenylene sulfide obtained in Reference Example 1 was charged into a glass ampule, and the inside of the ampule was replaced with nitrogen. An ampoule was placed in an electric furnace adjusted to 300 ° C., and heated for 60 minutes while maintaining the inside of the ampoule in a normal-pressure nitrogen atmosphere. The ampoule was taken out and cooled to room temperature to obtain a brown solid. From the absorption spectrum in the solid infrared spectroscopic analysis, it was confirmed that the solid was a compound (PPS) composed of phenylene sulfide units. The solid was completely dissolved in 1-chloronaphthalene at 250 ° C. As a result of HPLC measurement, it was found that the conversion of cyclic polyphenylene sulfide to PPS was 37%.

  As a result of GPC measurement, a peak derived from cyclic polyphenylene sulfide and a peak of the produced polymer (PPS) can be confirmed, and the obtained PPS has a weight average molecular weight of 75,000 and a dispersity of 1.7. all right. The results are shown in Table 1.

  From the comparison between Example 2 and Comparative Example 2, the cyclic polyphenylene sulfide was heated in the presence of bis (1,5-cyclooctadiene) nickel, which is a zero-valent transition metal compound, under devolatilization conditions. It was found that the conversion of sulfide to polyphenylene sulfide proceeds.

  From the comparison between Comparative Example 3 and Comparative Example 4, there was no effect due to devolatilization conditions in the absence of the zero-valent transition metal compound.

  From a comparison between Example 2 and Comparative Example 3, it was found that polyphenylene sulfide having a higher degree of polymerization can be obtained by heating under the devolatilization condition in the presence of a zero-valent transition metal compound.

Example 3
A black solid was obtained in the same manner as in Example 2 except that the amount of bis (1,5-cyclooctadiene) nickel was 3 mol%. From the absorption spectrum in the solid infrared spectroscopic analysis, it was confirmed that the solid was a compound (PPS) composed of phenylene sulfide units. The solid was partially insoluble in 1-chloronaphthalene at 250 ° C., but it was found that the insoluble part was not a compound having a phenylene sulfide structure but a nickel compound, and the produced PPS component was soluble. As a result of HPLC measurement, it was found that the conversion of cyclic polyphenylene sulfide to PPS was 95%.

  As a result of GPC measurement, a peak derived from cyclic polyphenylene sulfide and a peak of the produced polymer (PPS) can be confirmed, and the obtained PPS has a weight average molecular weight of 90000 and a dispersity of 2.5. all right. The results are shown in Table 1.

Example 4
A black solid was obtained in the same manner as in Example 1 except that the amount of bis (1,5-cyclooctadiene) nickel was 3 mol%. From the absorption spectrum in the solid infrared spectroscopic analysis, it was confirmed that the solid was a compound (PPS) composed of phenylene sulfide units. The solid was partially insoluble in 1-chloronaphthalene at 250 ° C., but it was found that the insoluble part was not a compound having a phenylene sulfide structure but a nickel compound, and the produced PPS component was soluble. As a result of HPLC measurement, it was found that the conversion rate of cyclic polyphenylene sulfide to PPS was 90%.

  As a result of GPC measurement, a peak derived from cyclic polyphenylene sulfide and a peak of the produced polymer (PPS) can be confirmed, and the weight average molecular weight of the obtained PPS is 97,000, and the dispersity is 2.3. all right. The results are shown in Table 1.

Comparative Example 5
A brown solid was obtained in the same manner as in Comparative Example 3 except that the heating temperature was 340 ° C. and the heating time was 120 minutes. From the absorption spectrum in the solid infrared spectroscopic analysis, it was confirmed that the solid was a compound (PPS) composed of phenylene sulfide units. The solid was completely dissolved in 1-chloronaphthalene at 250 ° C. As a result of HPLC measurement, it was found that the conversion of cyclic polyphenylene sulfide to PPS was 94%.

  As a result of GPC measurement, a peak derived from cyclic polyphenylene sulfide and a peak of the produced polymer (PPS) were confirmed, and it was found that the obtained PPS had a weight average molecular weight of 120,000 and a dispersity of 2.1. . The results are shown in Table 1.

  From the comparison between Example 3 and Example 2, it was found that the conversion of cyclic polyphenylene sulfide to polyphenylene sulfide was further promoted by increasing the amount of bis (1,5-cyclooctadiene) nickel added. .

  Further, as shown in Example 4, it was found that polyphenylene sulfide having a high degree of polymerization can be obtained in a shorter time by increasing the amount of bis (1,5-cyclooctadiene) nickel added.

  From Comparative Example 5, it was found that in the absence of a zero-valent transition metal, heating at a high temperature for a long time was necessary to obtain a polyphenylene sulfide having a high degree of polymerization.

Example 5
Instead of bis (1,5-cyclooctadiene) nickel used in Example 2, tetrakis (triphenylphosphite) nickel (described as Ni [P (OPh) ₃ ] _{4 in the} table, the same applies hereinafter) is used. Except that, the same operation as in Example 2 was performed to obtain a black solid. From the absorption spectrum in the solid infrared spectroscopic analysis, it was confirmed that the solid was a compound (PPS) composed of phenylene sulfide units. The solid was partially insoluble in 1-chloronaphthalene at 250 ° C., but it was found that the insoluble part was not a compound having a phenylene sulfide structure but a nickel compound, and the produced PPS component was soluble. As a result of HPLC measurement, it was found that the conversion of cyclic polyphenylene sulfide to PPS was 94%.

  As a result of GPC measurement, a peak derived from cyclic polyphenylene sulfide and a peak of the produced polymer (PPS) can be confirmed, and the weight average molecular weight of the obtained PPS is 23,000, and the dispersity is 2.0. all right. The results are shown in Table 2.

Comparative Example 6
A black solid was obtained in the same manner as in Comparative Example 2 except that tetrakis (triphenylphosphite) nickel was used instead of the bis (1,5-cyclooctadiene) nickel used in Comparative Example2. From the absorption spectrum in the solid infrared spectroscopic analysis, it was confirmed that the solid was a compound (PPS) composed of phenylene sulfide units. The solid was partially insoluble in 1-chloronaphthalene at 250 ° C., but it was found that the insoluble part was not a compound having a phenylene sulfide structure but a nickel compound, and the produced PPS component was soluble. As a result of HPLC measurement, it was found that the conversion of cyclic polyphenylene sulfide to PPS was 63%. The results are shown in Table 2.

  From comparison between Example 5 and Comparative Example 6, cyclic polyphenylene sulfide was heated in the presence of tetrakis (triphenylphosphite) nickel, which is a zero-valent transition metal compound, under devolatilization conditions. It was found that the conversion of polyphenylene sulfide to polyphenylene sulfide proceeds.

  On the other hand, from comparison between Example 5 and Example 2, tetrakis (triphenylphosphite) nickel is used in which the coordination between the zero-valent transition metal atom and the ligand is via the unshared electron pair of the phosphorus atom of the ligand. When the cyclic polyarylene sulfide is heated, bis (1,5-cyclooctadiene) nickel in which the coordination between the zero-valent transition metal atom and the ligand is not via the ligand's lone pair of electrons. It was found that polyphenylene sulfide having a high degree of polymerization tends to be hardly obtained as compared with the case where the cyclic polyarylene sulfide is heated.

  Factors tending to such a tendency are that the dissociation of the zero-valent transition metal atom and the ligand differs depending on the structure of the ligand, and the ligand and the cyclic polyarylene sulfide or polyarylene sulfide. It is speculated that the interaction with is different.

  When the coordination between the zero-valent transition metal atom and the ligand is via a lone pair of ligands, the coordination force tends to be relatively strong, and the zero-valent transition metal atom and the ligand dissociate. Is difficult to occur, and it is difficult for a zero-valent transition metal atom to form a free orbital capable of interacting with cyclic polyarylene sulfide or polyarylene sulfide, or a zero-valent transition metal atom due to steric hindrance of a zero-valent transition metal compound. The cyclic polyarylene sulfide or the polyarylene sulfide is difficult to approach, and the conversion of the cyclic polyarylene sulfide to the polyarylene sulfide and the further increase in the degree of polymerization of the polyarylene sulfide are unlikely to proceed. Yes.

  In addition, a ligand having an unshared electron pair in a zero-valent transition metal compound or a ligand having an unshared electron pair dissociated from a zero-valent transition metal atom can be converted into a cyclic polyarylene sulfide via the unshared electron pair. Alternatively, it is assumed that there is a tendency to stabilize the structure of cyclic polyarylene sulfide or polyarylene sulfide because it interacts with polyarylene sulfide, and by not including an unshared electron pair in the ligand structure, Cyclic polyarylene sulfide structure or polyarylene sulfide structure is not stabilized by a ligand dissociated from a zero-valent transition metal atom. Conversion from cyclic polyarylene sulfide to polyarylene sulfide and higher polymerization of polyarylene sulfide We believe that progress will be easy.

Example 6
100 mg of a powder obtained by mixing 1 mol% of nickel acetate and 20 mol% of zinc powder with respect to sulfur atoms in the cyclic polyphenylene sulfide was added to the glass polyample obtained in Reference Example 1 in a glass ampule. After the inside was replaced with nitrogen, the pressure was reduced to about 0.4 kPa using a vacuum pump. About 10 seconds after the pressure was reduced to about 0.4 kPa, the ampule was placed in an electric furnace adjusted to 300 ° C., and heated for 60 minutes while keeping the inside of the ampule at about 0.4 kPa with a vacuum pump and devolatilization. Thereafter, the ampule was taken out and cooled to room temperature to obtain a black solid. From the absorption spectrum in the solid infrared spectroscopic analysis, it was confirmed that the solid was a compound (PPS) composed of phenylene sulfide units. The solid was partially insoluble in 1-chloronaphthalene at 250 ° C., but it was found that the insoluble part was not a compound having a phenylene sulfide structure but a nickel compound and a zinc compound, and the produced PPS component was soluble. . As a result of HPLC measurement, it was found that the conversion ratio of cyclic polyphenylene sulfide to PPS was 53%. The results are shown in Table 3.

Comparative Example 7
100 mg of a powder obtained by mixing 1 mol% of nickel acetate and 20 mol% of zinc powder with respect to sulfur atoms in the cyclic polyphenylene sulfide was added to the glass polyample obtained in Reference Example 1 in a glass ampule. The inside was replaced with nitrogen. The ampule was placed in an electric furnace adjusted to 300 ° C. and heated for 60 minutes while keeping the inside of the ampule in a normal-pressure nitrogen atmosphere, and then the ampule was taken out and cooled to room temperature to obtain a black solid. From the absorption spectrum in the solid infrared spectroscopic analysis, it was confirmed that the solid was a compound (PPS) composed of phenylene sulfide units. The solid was partially insoluble in 1-chloronaphthalene at 250 ° C., but it was found that the insoluble part was not a compound having a phenylene sulfide structure but a nickel compound and a zinc compound, and the produced PPS component was soluble. . As a result of HPLC measurement, it was found that the conversion of cyclic polyphenylene sulfide to PPS was 27%. The results are shown in Table 3.

  From the comparison between Example 6 and Comparative Example 7, the cyclic polyphenylene sulfide was heated under devolatilization conditions in the presence of nickel acetate and zinc powder to convert the cyclic polyphenylene sulfide to the polyphenylene sulfide in a shorter time. Was found to progress.

  From the comparison between Example 6 and Comparative Example 3, the conversion of cyclic polyphenylene sulfide to polyphenylene sulfide proceeds by heating cyclic polyphenylene sulfide in the presence of nickel acetate and zinc powder under devolatilization conditions. I understood.

  These are considered to be because a zero-valent transition metal compound was produced in the system from nickel acetate as a transition metal salt and reducing zinc powder.

Example 7
500 mg of powder obtained by mixing 1 mol% of bis (1,5-cyclooctadiene) nickel with respect to the sulfur atom in the cyclic polyphenylene sulfide to the cyclic polyphenylene sulfide obtained in Reference Example 1 is charged into a glass ampule. After replacing the inside of the ampule with nitrogen, the pressure was reduced to about 0.4 kPa using a vacuum pump. About 10 seconds after the pressure was reduced to about 0.4 kPa, an ampule was installed in the electric furnace, the temperature was raised from 50 ° C. to 300 ° C. at 15 ° C./min, held at 300 ° C. for 5 minutes, and the ampule was taken out. Cooled to room temperature to give a black solid. From the absorption spectrum in the solid infrared spectroscopic analysis, it was confirmed that the solid was a compound (PPS) composed of phenylene sulfide units. The solid was partially insoluble in 1-chloronaphthalene at 250 ° C., but it was found that the insoluble part was not a compound having a phenylene sulfide structure but a nickel compound, and the produced PPS component was soluble. As a result of HPLC measurement, it was found that the conversion of cyclic polyphenylene sulfide to PPS was 29%. The results are shown in Table 4.

  The obtained solid was subjected to XPS measurement, and the valence state of the nickel compound and the structure near the nickel atom were analyzed. As a result, from the Ni2p peak position (in the vicinity of the binding energy of 856 eV) and the peak shape, a component derived from zero-valent nickel is recognized near the binding energy of 853 eV, although the nickel-valent nickel is the main component. It was found that there was a mixture.

Example 8
500 mg of powder obtained by mixing 1 mol% of nickel chloride and 20 mol% of zinc powder with respect to the sulfur atoms in the cyclic polyphenylene sulfide was charged into the ampule made of glass to the cyclic polyphenylene sulfide obtained in Reference Example 1. After the inside was replaced with nitrogen, the pressure was reduced to about 0.4 kPa using a vacuum pump. About 10 seconds after the pressure was reduced to about 0.4 kPa, an ampule was installed in the electric furnace, the temperature was raised from 50 ° C. to 300 ° C. at 15 ° C./min, held at 300 ° C. for 5 minutes, and the ampule was taken out. Cooled to room temperature to give a black solid. From the absorption spectrum in the solid infrared spectroscopic analysis, it was confirmed that the solid was a compound (PPS) composed of phenylene sulfide units. The solid was partially insoluble in 1-chloronaphthalene at 250 ° C., but it was found that the insoluble part was not a compound having a phenylene sulfide structure but a nickel compound and a zinc compound, and the produced PPS component was soluble. . As a result of HPLC measurement, it was found that the conversion of cyclic polyphenylene sulfide to PPS was 29%. The results are shown in Table 4.

  The obtained solid was subjected to XAFS measurement, and the valence state of the nickel compound and the structure in the vicinity of the nickel atom were analyzed. As a result, in the absorption spectrum related to XANES, a main peak near 8346 eV considered to be derived from II-valent nickel was observed, and a peak near 0.17 nm considered to be derived from Ni—Cl bond was observed in the radial distribution function. Therefore, although nickel chloride, which is a II-valent nickel compound, is the main component, in the XANES-related absorption spectrum, the pre-edge region intensity around 8330 eV tends to be larger (about twice) than the absorption spectrum of nickel chloride. It was recognized that a zero-valent nickel metal component was mixed. It is thought that the nickel metal component of zero valence and zinc chloride were produced from nickel chloride and zinc.

Comparative Example 8
500 mg of the cyclic polyphenylene sulfide obtained in Reference Example 1 was charged into a glass ampule, and the inside of the ampule was replaced with nitrogen. An ampule is installed in the electric furnace, the temperature is increased from 50 ° C. to 300 ° C. at 15 ° C./min while maintaining the inside of the ampule in a normal nitrogen atmosphere, and the temperature is maintained at 300 ° C. for 5 minutes. Cooled to a brown solid. From the absorption spectrum in the solid infrared spectroscopic analysis, it was confirmed that the solid was a compound (PPS) composed of phenylene sulfide units. The solid was completely dissolved in 1-chloronaphthalene at 250 ° C. As a result of HPLC measurement, it was found that the conversion of cyclic polyphenylene sulfide to PPS was 6%. The results are shown in Table 4.

  From the comparison between Example 7 and Comparative Example 8, it was found that the cyclic polyphenylene sulfide was heated in the presence of bis (1,5-cyclooctadiene) nickel, which is a zero-valent transition metal compound, under devolatilizing conditions for a shorter time. It was found that the conversion of cyclic polyphenylene sulfide to polyphenylene sulfide proceeds.

  From the comparison between Example 8 and Comparative Example 8, the cyclic polyphenylene sulfide was heated under devolatilization conditions in the presence of nickel chloride and zinc powder, thereby converting the cyclic polyphenylene sulfide to the polyphenylene sulfide in a shorter time. Was found to progress.

  In addition, in the XPS measurement in Example 7 and the XAFS measurement in Example 8, in the polymer in which the conversion of the cyclic polyphenylene sulfide to the polyphenylene sulfide is promoted, a zero-valent nickel component that is a zero-valent transition metal compound is present. I found it.

Claims (8)

A method for producing a polyarylene sulfide, comprising heating a cyclic polyarylene sulfide in the presence of a zero-valent transition metal compound under devolatilization conditions. The zero-valent transition metal compound is a compound in which a ligand is coordinated to a zero-valent transition metal atom without using a lone pair derived from a ligand. A method for producing polyarylene sulfide. The zero-valent transition metal compound is a compound in which a ligand is coordinated to a zero-valent transition metal atom via an unsaturated bond site of the ligand. A process for producing polyarylene sulfide as described in 1. above. The method for producing a polyarylene sulfide according to any one of claims 1 to 3, wherein the ligand structure constituting the zero-valent transition metal compound does not include an unshared electron pair. The method for producing a polyarylene sulfide according to any one of claims 1 to 4, wherein the ligand constituting the zero-valent transition metal compound is 1,5-cyclooctadiene. The method for producing polyarylene sulfide according to claim 1, wherein the zero-valent transition metal compound is a compound having no ligand. The metal constituting the zero-valent transition metal compound is at least one metal selected from metals of Groups 8 to 11 and Periods 4 to 6 of the periodic table. 6. A process for producing a polyarylene sulfide as described in 6. The method for producing polyarylene sulfide according to claim 1, wherein the zero-valent transition metal compound is a zero-valent nickel compound.