JP6354339B2 - Process for producing polyarylene sulfide - Google Patents

Description

  The present invention relates to a method for producing polyarylene sulfide, and more particularly to a method for producing polyarylene sulfide, which comprises heating cyclic polyarylene sulfide in the presence of a transition metal compound.

  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 is widely used in various fields that require 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. It is described that arylene sulfide is obtained.

  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 catalyst promoting effect and the degree of polymerization of polyarylene sulfide are not sufficient, and higher polymerization is achieved at a lower temperature and in a shorter time. A method for producing a polyarylene sulfide having a desired degree 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.

  In particular, zero-valent transition metal compounds such as tetrakis (triphenylphosphine) palladium described in Patent Document 6 have a high effect of promoting the conversion of cyclic polyarylene sulfide to polyarylene sulfide, but have low stability. It is an object of the present invention to provide a production method that uses a catalyst that has a tendency and is more stable and easy to handle. Another object of the present invention is to provide a method for producing a polyarylene sulfide having a higher degree of polymerization in order to further improve properties such as mechanical strength and chemical resistance of the polyarylene sulfide molded product.

  The present invention is a method for producing a polyarylene sulfide, which comprises heating a cyclic polyarylene sulfide in the presence of a transition metal compound represented by the following general formula.

That is, the present invention is as follows.
(1) A method for producing a polyarylene sulfide, comprising heating a cyclic polyarylene sulfide in the presence of a transition metal compound represented by the following general formula in a non-oxidizing atmosphere .

(Here, M represents a transition metal atom selected from metals in groups 8 to 11 and 4 to 6 in the periodic table excluding nickel, m represents an integer of 0 to 10, and n represents M R ¹ and R ² are each an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 24 carbon atoms, and halogen. Represents a substituent selected from the group consisting of a group, the hydrogen atom of the alkyl group, the alkoxy group or the aryl group may be substituted with a halogen atom, and R ¹ and R ² may be the same or different. May be good.)
(2) The process for producing polyarylene sulfide according to (1), wherein m of the transition metal compound represented by the general formula is 0.
(3) Substitution wherein R ¹ of the transition metal compound represented by the general formula is selected from the group consisting of an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, and an aryl group having 6 to 24 carbon atoms R ² is a substituent selected from the group consisting of an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, and an aryl group having 6 to 24 carbon atoms ( A process for producing a polyarylene sulfide as described in 1) or (2).
(4) R ¹ of the transition metal compound represented by the general formula is a substituent selected from an alkyl group having 1 to 12 carbon atoms, and R ² is a substituent selected from an alkyl group having 1 to 12 carbon atoms. The method for producing polyarylene sulfide as described in (1) or (2) above.
(5) R ¹ and R ² of the transition metal compound represented by the above general formula are methyl groups, or R ² is a substituent selected from alkyl groups having 1 to 12 carbon atoms (1 ) Or the method for producing polyarylene sulfide according to (2).
(6) The process for producing a polyarylene sulfide according to any one of (1) to (5), wherein M of the transition metal compound represented by the general formula is palladium or platinum.
(7) The method for producing a polyarylene sulfide according to any one of (1) to (6), wherein the heating is performed under a pressure equal to or higher than atmospheric pressure.

  According to the present invention, in the production of polyarylene sulfides by heating cyclic polyarylene sulfides, a polyarylene sulfide having a higher degree of polymerization can be obtained at a lower temperature and in a shorter time than conventional methods. Furthermore, it is possible to provide a production method using a catalyst having a high effect of promoting the conversion of cyclic polyarylene sulfide to polyarylene sulfide and having excellent stability.

  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.

(R ³ and R ⁴ are each a substituent 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; ³ and R ⁴ 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.

  In addition, 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 eluted components when in contact with the solvent. The weight average molecular weight and number average molecular weight can be determined using, for example, SEC (size exclusion chromatography) equipped with a differential refractive index detector.

  The method for producing polyarylene sulfide of the present invention is characterized in that the cyclic polyarylene sulfide is heated in the presence of the transition metal compound represented by the above general formula, and according to this method, the present invention having the above-mentioned characteristics can be easily obtained. Of polyarylene sulfide 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 rate of the cyclic polyarylene sulfide to the polyarylene sulfide is determined by the mass of the cyclic polyarylene sulfide contained in the raw material before heating and the unreacted cyclic polyarylene sulfide contained in the product obtained by heating. The mass can be quantified using high performance liquid chromatography (HPLC) and calculated from the value. In particular,
Conversion rate = (mass of cyclic polyarylene sulfide contained in raw material before heating−mass of unreacted cyclic polyarylene sulfide) / mass of cyclic polyarylene sulfide contained in raw material before heating be able to.

<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 p 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 with small p tend to have low reactivity, it is preferable to set p within 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 higher than the temperature at which the cyclic polyarylene sulfide is melted. 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 p in 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.

<Transition metal compounds>
In the present invention, various transition metal compounds represented by the following general formula are used as a polymerization catalyst.

(Here, M represents a transition metal atom selected from metals in groups 8 to 11 and 4 to 6 in the periodic table excluding nickel, m represents an integer of 0 to 10, and n represents M R ¹ and R ² are each an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 24 carbon atoms, and halogen. Represents a substituent selected from the group consisting of a group, the hydrogen atom of the alkyl group, the alkoxy group or the aryl group may be substituted with a halogen atom, and R ¹ and R ² may be the same or different. May be good.)

  If m is an integer of 0 to 10, it is effective as a polymerization catalyst. However, from the viewpoint of the steric stability of the transition metal compound structure, 0 to 5 is preferable, and the electronic structure of the transition metal compound structure is preferred. From the viewpoint of stability, a resonance structure can be taken, and therefore 0 is more preferable.

  n is the same integer as the valence of the transition metal atom M.

R ¹ and R ² can be used as a polymerization catalyst if they are substituents selected from the group consisting of alkyl groups having 1 to 12 carbon atoms, alkoxy groups having 1 to 12 carbon atoms, aryl groups having 6 to 24 carbon atoms, and halogen groups. It is effective, and the hydrogen atom of the alkyl group, the alkoxy group or the aryl group may be substituted with a halogen atom, and R ¹ and R ² may be the same or different. For example, methyl, ethyl, propyl, isopropyl, butyl, butyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl and their halogen substituents, methoxy, ethoxy, propyloxy, pentyloxy, hexyloxy , Heptyloxy, octyloxy, nonyloxy, decyloxy, undecyloxy, dodecyloxy and their halogen substitutes, phenyl, benzyl, tolyl, xylyl, biphenyl, naphthyl and their halogen substitutes, fluorine, chlorine, bromine, iodine, etc. Can be illustrated. Specific examples of the transition metal compound include tris (2,4-pentandionato) iron, tris (trifluoro-2,4-pentandionato) iron, tris (hexafluoroacetylacetonato) iron, and tris (dibenzoylme). Tanato) iron, tris (2,4-pentanedionato) ruthenium, bis (2,4-pentanedionato) cobalt, bis (trifluoro-2,4-pentandedionato) cobalt, bis (hexafluoroacetylacetonate) ) Cobalt, Tris (2,4-pentandionato) cobalt, Tris (2,4-pentandionato) rhodium, Tris (2,4-pentandionato) iridium, Bis (2,4-pentandionato) palladium Bis (hexafluoro-2,4-pentanedionato) palladium, bis (2,4-pentandedionato) Gold, bis (hexafluoro-2,4-pentanedionato) platinum, bis (2,4-pentanedionato) copper, bis (trifluoro-2,4-pentandedionato) copper, bis (hexafluoroacetylacetate) Nato) copper, bis (2,2,6,6-tetramethyl-3,5-heptanedionato) copper, copper ethylacetoacetate and the like.

Among them, if R ¹ and R ² are electron donating groups, the effect of accelerating the conversion of cyclic polyarylene sulfide tends to be large, and therefore an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, And a substituent selected from the group consisting of aryl groups having 6 to 24 carbon atoms. For example, methyl, ethyl, propyl, isopropyl, butyl, butyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl and their halogen substituents, methoxy, ethoxy, propyloxy, pentyloxy, hexyloxy , Heptyloxy, octyloxy, nonyloxy, decyloxy, undecyloxy, dodecyloxy and their halogen substituents, phenyl, benzyl, tolyl, xylyl, biphenyl, naphthyl and their halogen substituents. Specific examples of the transition metal compound include tris (2,4-pentandionato) iron, tris (dibenzoylmethanato) iron, tris (2,4-pentandionato) ruthenium, and bis (2,4-pentandionato). ) Cobalt, Tris (2,4-pentandionato) cobalt, Tris (2,4-pentandionato) rhodium, Tris (2,4-pentandionato) iridium, Bis (2,4-pentandionato) palladium Bis (2,4-pentanedionato) platinum, bis (2,4-pentandedionato) copper, bis (2,2,6,6-tetramethyl-3,5-heptaneedionato) copper, copper ethylacetoacetate, etc. Can be illustrated.

  Furthermore, from the viewpoint of steric stability of the transition metal compound structure, it is more preferably an alkyl group having 1 to 12 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, butyl, butyl, pentyl, hexyl, Examples include heptyl, octyl, nonyl, decyl, undecyl, dodecyl, and halogen-substituted products thereof. Specific examples of the transition metal compound include tris (2,4-pentandionato) iron, tris (2,4-pentandionato) ruthenium, bis (2,4-pentandionato) cobalt, and tris (2,4 -Pentandionato) cobalt, tris (2,4-pentandionato) rhodium, tris (2,4-pentandionato) iridium, bis (2,4-pentandionato) palladium, bis (2,4-pentane) Examples include diato) platinum, bis (2,4-pentanedionate) copper, and bis (2,2,6,6-tetramethyl-3,5-heptanedionate) copper.

  Among these, a methyl group that can achieve both electron donating properties and steric stability of the transition metal compound structure and is excellent in the availability and handling of the transition metal compound is most preferable. Specific examples of the transition metal compound include tris (2,4-pentandionato) iron, tris (2,4-pentandionato) ruthenium, bis (2,4-pentandionato) cobalt, and tris (2,4 -Pentandionato) cobalt, tris (2,4-pentandionato) rhodium, tris (2,4-pentandionato) iridium, bis (2,4-pentandionato) palladium, bis (2,4-pentane) Zionato) platinum, bis (2,4-pentanedionato) copper, and the like.

  The transition metal species is effective as a polymerization catalyst as long as it is a transition metal atom selected from metals in groups 8 to 11 and 4 to 6 in the periodic table excluding nickel, specifically iron, ruthenium, Examples include osmium, cobalt, rhodium, iridium, palladium, platinum, copper, silver, and gold. The reason for this is not clear at this time, however, because these transition metal atoms can take many valence states, because the atomic radius of these transition metal atoms tends to interact with the cyclic polyarylene sulfide structure, or It is presumed that these transition metal atoms can form a transition metal compound that is easily dispersed in the cyclic polyarylene sulfide.

  Among these transition metal species, palladium and platinum are preferred because they tend to have a high effect of promoting the conversion of cyclic polyarylene sulfide. 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.

  The present invention is characterized in that the cyclic polyarylene sulfide is heated in the presence of the transition metal compound represented by the general formula. The transition metal compound represented by the general formula may be added as a raw material, or within the system. A transition metal compound represented by the general formula may be generated. Moreover, you may use individually by 1 type and may use 2 or more types together. Here, in order to generate the transition metal compound represented by the general formula in the system as in the latter case, for example, it is generated from the transition metal salt and acetylacetone as used in a general method for synthesizing acetylacetonate compounds in a solution. The method of making it, etc. are mentioned.

  The valence state of the transition metal atom, the bond or coordination state of the transition metal atom and the oxygen atom, etc. can be grasped by, for example, X-ray absorption fine structure (XAFS) analysis. By irradiating a transition metal compound used as a catalyst in the present invention, or a cyclic polyarylene sulfide containing a transition metal compound, or a polyarylene sulfide containing a transition metal compound with X-rays, and comparing the absorption spectra. I can grasp.

  The concentration of the transition metal compound to be used varies depending on the molecular weight of the target polyarylene sulfide and the kind of the polymerization catalyst. Usually, the lower limit is 0.001 mol% or more based on the sulfur atom in the cyclic polyarylene sulfide. Is preferable, more preferably 0.005 mol% or more, and still more preferably 0.01 mol% or more. At 0.001 mol%, the cyclic polyarylene sulfide is fully converted to polyarylene sulfide. On the other hand, as an upper limit, 20 mol% or less is preferable with respect to the sulfur atom in cyclic polyarylene sulfide, More preferably, it is 15 mol% or less, More preferably, 10 mol% or less can be illustrated. If it is 20 mol% or less, a polyarylene sulfide having the above-mentioned properties can be obtained. The concentration of the transition metal compound here refers to the concentration when the transition metal compound represented by the general formula is added as a raw material. On the other hand, when the transition metal compound represented by the general formula is generated in the system, it refers to the concentration of the transition metal salt added as a raw material.

  When adding the transition metal compound represented by the general formula or the transition metal salt for generating the transition metal compound represented by the general formula in the system, it may be added as it is, but it is uniformly added to the cyclic polyarylene sulfide. It is preferable to disperse. 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, a method in which cyclic polyarylene sulfide is dissolved or dispersed in an appropriate solvent, a transition metal compound or a transition metal salt is added thereto in a predetermined amount, and then the solvent is removed. Can be illustrated.

  As a method of melting and dispersing cyclic polyarylene sulfide, a method of melting a cyclic polyarylene sulfide by heating after adding a transition metal compound or a transition metal salt to a cyclic polyarylene sulfide in a solid state, Examples thereof include a method of adding a transition metal compound and a transition metal salt after melting the polyarylene sulfide.

  As a method of dispersing in a polymerization reaction apparatus, a mold for producing a molded article, an apparatus such as an extruder or a melt kneader in advance, a predetermined amount of a transition metal compound or a transition metal salt is added to an appropriate solvent. Thereafter, a polymerization reaction apparatus, a mold for producing a molded article, a method of dispersing by removing the solvent in an apparatus such as an extruder or a melt kneader can be exemplified.

  As a method of dispersing on a fibrous material in advance, a method of dispersing as it is, after adding a predetermined amount of a transition metal compound or a transition metal salt to an appropriate solvent, and then applying or spraying or impregnating the fibrous material Examples thereof include a method of dispersing 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.

  Moreover, when a transition metal compound and a transition metal salt are solid, since more uniform dispersion | distribution is attained, it is preferable that those average particle diameters are 1 mm or less.

  Moreover, since the transition metal compound represented by the general formula used in the present invention tends to have high stability, it is preferable to add it in a non-oxidizing atmosphere, but it is also possible to add it in the air. Non-oxidizing atmosphere means that the oxygen concentration in the gas phase in contact with cyclic polyarylene sulfide, transition metal compound, and transition metal salt is 5% by volume or less, preferably 2% by volume or less, more preferably substantially free of oxygen. It indicates an atmosphere, that is, an inert gas atmosphere such as nitrogen, helium or argon, and a nitrogen atmosphere is preferred from the viewpoint of economy and ease of handling. The term “in the atmosphere” means that the atmosphere has a general composition with an oxygen concentration of about 21% by volume.

  The temperature at the time of adding the transition metal compound represented by the general formula and the transition metal salt for generating the transition metal compound represented by the general formula in the system is particularly within the temperature range in which the method used for the addition can be performed. Although there is no limitation, the upper limit is preferably a temperature range in which the cyclic polyarylene sulfide is not easily converted to polyarylene sulfide, for example, 300 ° C. or lower, preferably 260 ° C. or lower, more preferably 240 ° C. or lower, still more preferably Is 220 ° C. or lower, more preferably 200 ° C. or lower, and still more preferably 180 ° C. or lower. Moreover, although it changes with the kind of polymerization catalyst to be used, it is preferable that a polymerization catalyst is a temperature range which is hard to accelerate | stimulate conversion of cyclic polyarylene sulfide to polyarylene sulfide.

<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 and the transition metal compound represented by the general formula and the cyclic polyarylene sulfide are easily compatible with each other, and the transition metal compound represented by the general formula and the cyclic polyarylene sulfide are Interaction is likely to occur, and a polyarylene sulfide having a high degree of polymerization can be obtained in a short time. On the other hand, if the temperature is too high, undesirable side reactions represented by crosslinking 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 atmosphere in heating the cyclic polyarylene sulfide is preferably a non-oxidizing atmosphere. 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, argon, etc. In particular, a nitrogen atmosphere is preferable from the viewpoint of economy and ease of handling. This tends to suppress the occurrence of undesirable side reactions such as cross-linking reactions and decomposition reactions between cyclic polyarylene sulfides, between polyarylene sulfides generated by heating, and between polyarylene sulfides and cyclic polyarylene sulfides. .

  The heating of the cyclic polyarylene sulfide is not limited to atmospheric pressure as long as it is in a non-oxidizing atmosphere, and can be performed under reduced pressure conditions or devolatilization conditions.

  The reduced pressure condition means that the reaction system is lower than atmospheric pressure, and the upper limit is preferably 50 kPa or less, more preferably 20 kPa or less, and even more preferably 10 kPa or less. An example of the lower limit is 0.1 kPa or more, and 0.2 kPa or more is more preferable. When the decompression condition is at least the preferred lower limit, the cyclic compound of the formula (O) having a low molecular weight contained in the cyclic polyarylene sulfide is less likely to be volatilized. Thus, a polyarylene sulfide having the above-described characteristics can be obtained. Moreover, when it carries out under pressure reduction conditions, it is preferable to make it the pressure reduction conditions after making the atmosphere in a reaction system once non-oxidizing atmosphere.

  The devolatilization condition is a condition for removing a gaseous component generated when the cyclic polyarylene sulfide is heated in the presence of the transition metal compound represented by the general formula 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 presence or degree of the occurrence varies, but for example, polyarylene sulfide oligomers, cyclic metal compound components, transitions contained in cyclic polyarylene sulfides. Examples include decomposition products in the metal compound structure, decomposition products in the transition metal salt structure added when the transition metal compound represented by the general formula in the system is formed, and the like. 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 polyarylene sulfide oligomer hardly remains in the heating system, and the weight ratio of the (O) cyclic compound and the polyarylene sulfide oligomer in the cyclic polyarylene sulfide in the heating system. Therefore, the polyarylene sulfide obtained by the method for producing polyarylene sulfide of the present invention is preferable in that the weight average molecular weight tends to increase.

  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. By performing devolatilization under reduced pressure continuously, the polyarylene sulfide oligomer contained in the cyclic polyarylene sulfide can be removed from the heating system more efficiently. It 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. This tends to suppress the occurrence of undesirable side reactions such as cross-linking reactions and decomposition reactions between cyclic polyarylene sulfides, between polyarylene sulfides generated by heating, and between polyarylene sulfides and cyclic polyarylene sulfides. .

  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. This tends to suppress the occurrence of undesirable side reactions such as cross-linking reactions and decomposition reactions between cyclic polyarylene sulfides, between polyarylene sulfides generated by heating, and between polyarylene sulfides and cyclic polyarylene sulfides. . The gas to be used is preferably an inert gas such as nitrogen, helium or argon, and among these, nitrogen gas is particularly preferred from the viewpoint 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 the cyclic polyarylene sulfide is present in the presence of the transition metal compound represented by the general formula. There is no particular limitation as long as the gaseous component generated during heating can be removed from the heating system and the heating temperature in the system can be stably controlled. However, in view of the effect of removing the gaseous component generated when the cyclic polyarylene sulfide is heated in the presence of the transition metal compound represented by the general formula from the inside of the heating system, it flows into the system in 1 minute. The gas 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 be illustrated as a range.

  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 heating of the cyclic polyarylene sulfide is also preferably performed under a condition of 50 kPa or more in a non-oxidizing atmosphere. The condition of 50 kPa or more is preferred in that the polymerization catalyst tends to hardly evaporate during heating, and polyarylene sulfide can be obtained in a short time. From the viewpoint that the polymerization catalyst is less likely to evaporate during heating, the condition may be 50 kPa or more, more preferably 70 kPa or more, further preferably 90 kPa or more, and even more under atmospheric pressure. It is more preferable that the pressure is higher than atmospheric pressure. Although there is no restriction | limiting in particular as an upper limit of pressurization conditions, 0.2 MPa or less is preferable from the surface of the ease of handling of a reactor. Moreover, when heating is performed under conditions of 50 kPa or more, it is preferable that the atmosphere in the reaction system is once changed to a non-oxidizing atmosphere and then set to a target pressure condition. This tends to suppress the occurrence of undesirable side reactions such as cross-linking reactions and decomposition reactions between cyclic polyarylene sulfides, between polyarylene sulfides generated by heating, and between polyarylene sulfides and cyclic polyarylene sulfides. .

  The reaction time is such as the content of the cyclic compound of the formula (O) in the cyclic polyarylene sulfide used, the number of repetitions p, and the molecular weight, 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. The lower limit of the heating time can be exemplified by 0.01 hours or more, preferably 0.05 hours or more. In 0.01 hours or more, the cyclic polyarylene sulfide is sufficiently converted to polyarylene sulfide. On the other hand, as an upper limit, 100 hours or less can be illustrated, Preferably it is 20 hours or less, More preferably, 10 hours or less can be illustrated. 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. When the time is less than 100 hours, adverse effects on the properties of the polyarylene sulfide obtained 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 can be used without particular limitation, and a known method such as a batch method or 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 having a tensile strength of 450 kgf / mm ² and a tensile elongation of 1.6% or more. Fiber is most suitable. In the case of using long fiber-like reinforcing fibers, the length is preferably 5 cm or more. In the range of this length, it becomes easy to sufficiently develop the strength of the reinforcing fiber as a composite material. Carbon fibers and graphite fibers may be used in combination with other reinforcing fibers. Moreover, the shape and arrangement | sequence of a reinforced fiber are not limited, For example, 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 weight of polyarylene sulfide and cyclic polyarylene sulfide is 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).

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.

  The content obtained was analyzed by gas chromatography and high performance liquid chromatography. As a result, the consumption rate of monomer p-DCB was 96%, and all the sulfur components in the reaction mixture were assumed to be 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 while 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
Unopened bis (2,4-pentanedionato) palladium sealed in an inert atmosphere to the cyclic polyphenylene sulfide obtained in Reference Example 1 (described as Pd (acac) _{2 in the} table, the same applies hereinafter) Was opened and mixed in a nitrogen atmosphere at 1 mol% with respect to the sulfur atoms in the cyclic polyphenylene sulfide, and 300 mg of the mixed powder was charged into a glass ampule, and the ampule 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 palladium 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 61%.

Example 2
1 mol% of unopened bis (2,4-pentanedionato) palladium sealed in an inert atmosphere to the cyclic polyphenylene sulfide obtained in Reference Example 1 with respect to the sulfur atom in the cyclic polyphenylene sulfide. After opening and mixing in a nitrogen atmosphere, 300 mg of the mixed powder was charged into a glass ampoule, the inside of the ampoule 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 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 palladium 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 57%.

  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.

Example 3
Instead of bis (2,4-pentanedionato) palladium used in Example 1, bis (2,4-pentanedionato) platinum (described as Pt (acac) _{2 in the} table, the same applies hereinafter) was used. Except that, the same operation as in Example 1 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 platinum 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 46%.

Comparative Example 1
300 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.

Comparative Example 2
300 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.

  From the comparison between Example 1, Example 3 and Comparative Example 1, bis (2,4-pentanedionato) palladium, bis (2,4-pentanedioe), which is a transition metal compound represented by the general formula, of cyclic polyphenylene sulfide. Nato) It was found that the conversion of cyclic polyphenylene sulfide to polyphenylene sulfide proceeds in a shorter time by heating in the presence of platinum in a nitrogen atmosphere at normal pressure.

  From the comparison between Example 2 and Comparative Example 2, the cyclic polyphenylene sulfide was heated under devolatilization conditions in the presence of bis (2,4-pentanedionato) palladium, which is a transition metal compound represented by the general formula, It was found that the conversion of cyclic polyphenylene sulfide to polyphenylene sulfide proceeded in a shorter time.

  Further, from the comparison between Example 1 and Example 2, the effect of bis (2,4-pentanedionato) palladium, which is a transition metal compound represented by the general formula, promoting the conversion of cyclic polyphenylene sulfide to polyphenylene sulfide is It was found that even under a normal pressure nitrogen atmosphere, it was equivalent to the devolatilization condition.

Example 4
A black solid was obtained by performing the same operation as in Example 1 except that the heating time was changed to 10 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 palladium 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 2.

Example 5
A black solid was obtained by performing the same operation as in Example 2 except that the heating time was changed to 10 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 palladium 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 54%. 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 105,000 and a dispersity of 2.5. all right. The results are shown in Table 2.

Example 6
A black solid was obtained by performing the same operation as in Example 3 except that the heating time was changed to 10 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 platinum 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 31%. The results are shown in Table 2.

Comparative Example 3
A brown solid was obtained in the same manner as in Comparative Example 1 except that the heating time was changed to 10 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 12%. The results are shown in Table 2.

Comparative Example 4
A brown solid was obtained in the same manner as in Comparative Example 2 except that the heating time was changed to 10 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 11%. The results are shown in Table 2.

  From comparison between Example 4, Example 6 and Comparative Example 3, bis (2,4-pentanedionato) palladium, bis (2,4-pentanedioe), which is a transition metal compound represented by the general formula, is obtained by converting cyclic polyphenylene sulfide. Nato) It was found that the conversion of cyclic polyphenylene sulfide to polyphenylene sulfide proceeds in a shorter time by heating in the presence of platinum in a nitrogen atmosphere at normal pressure.

From the comparison between Example 5 and Comparative Example 4, the cyclic polyphenylene sulfide was heated under devolatilization conditions in the presence of bis (2,4-pentanedionato) palladium, which is a transition metal compound represented by the general formula, It was found that the conversion of cyclic polyphenylene sulfide to polyphenylene sulfide proceeded in a shorter time.

  Further, from the comparison between Example 4 and Example 5, the effect of bis (2,4-pentanedionato) palladium, which is a transition metal compound represented by the general formula, promotes the conversion of cyclic polyphenylene sulfide to polyphenylene sulfide. It was found that even under a normal pressure nitrogen atmosphere, it was equivalent to the devolatilization condition.

Claims (7)

A method for producing a polyarylene sulfide, comprising heating a cyclic polyarylene sulfide in the presence of a transition metal compound represented by the following general formula in a non-oxidizing atmosphere .

(Here, M represents a transition metal atom selected from metals in groups 8 to 11 and 4 to 6 in the periodic table excluding nickel, m represents an integer of 0 to 10, and n represents M R ¹ and R ² are each an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 24 carbon atoms, and halogen. Represents a substituent selected from the group consisting of a group, the hydrogen atom of the alkyl group, the alkoxy group or the aryl group may be substituted with a halogen atom, and R ¹ and R ² may be the same or different. May be good.) The process for producing polyarylene sulfide according to claim 1, wherein m of the transition metal compound represented by the general formula is 0. R ¹ of the transition metal compound represented by the general formula is a substituent selected from the group consisting of an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, and an aryl group having 6 to 24 carbon atoms. Wherein R ² is a substituent selected from the group consisting of an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, and an aryl group having 6 to 24 carbon atoms. 3. A process for producing a polyarylene sulfide as described in 2. R ¹ of the transition metal compound represented by the general formula is a substituent selected from an alkyl group having 1 to 12 carbon atoms, and R ² is a substituent selected from an alkyl group having 1 to 12 carbon atoms. A process for producing a polyarylene sulfide according to claim 1 or 2. The method for producing polyarylene sulfide according to claim 1 or 2, wherein R ¹ and R ² of the transition metal compound represented by the general formula are methyl groups. 6. The method for producing polyarylene sulfide according to claim 1, wherein M of the transition metal compound represented by the general formula is palladium or platinum. The method for producing a polyarylene sulfide according to any one of claims 1 to 6, wherein the heating is performed under a pressure equal to or higher than atmospheric pressure.