JP3216228B2 - Method for producing polyarylene sulfide - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyarylene sulfide and a method for producing the same, and more particularly, to a polyarylene sulfide having a narrow molecular weight distribution excellent in mechanical properties, heat resistance and chemical resistance. The present invention relates to a method for producing a polyarylene sulfide having advantages, and more particularly to a method for producing a polyarylene sulfide characterized by ring-opening polymerization of a cyclic arylene sulfide oligomer.

[0002] Polyarylene sulfide has attracted attention as a member for electric and electronic equipment and a member for automobile equipment by utilizing its excellent heat resistance and chemical resistance. In addition, injection molding,
It can be formed into various molded parts, films, sheets, fibers and the like by extrusion molding and the like, and is widely used in fields requiring heat resistance and chemical resistance.

[0003]

2. Description of the Related Art As a method for producing polyarylene sulfide, a dihalo aromatic compound and an alkali such as sodium sulfide are dissolved in an organic amide solvent such as N-methylpyrrolidone as disclosed in Japanese Patent Publication No. 45-3368. Desalting polycondensation by a nucleophilic substitution reaction with a metal compound is common.

However, this production method uses an aromatic nucleophilic substitution reaction having low reactivity, so that it requires a reaction under a high temperature and a high pressure, and requires an expensive high boiling point polar solvent such as N-methylpyrrolidone. It is energy-consuming and requires a great deal of cost for solvent recovery, requiring a great deal of process cost. Furthermore, since a large amount of by-product salt such as sodium chloride is generated, a step of washing and removing the by-product salt is required, which complicates the process, and it is difficult to completely remove the by-product salt by ordinary treatment such as washing with water. .

In addition, since the polymer chain end obtained by this method contains chlorine and sodium, commercial products have a sodium content of 1000 to 3000 ppm.
If the alkali metal salt remains in the produced polymer, there arises a problem that physical properties such as electric properties are deteriorated. Therefore, when attempting to apply a molded article using such a polyarylene sulfide as a raw material to the field of electric and electronic components, a decrease in electric properties due to a large amount of sodium and chlorine such as salt in the polyarylene sulfide is a major obstacle. Become. In other words, when polyarylene sulfide containing a large amount of sodium and chlorine is used for sealing electronic components such as ICs, for example, the insulation of the circuit is reduced due to moisture absorption, and the electrodes and lead frames are corroded. It is known that the characteristics of the element may be deteriorated or a failure may occur, such as disconnection.

[0006] The polyarylene sulfide obtained by this method is a polymer having a low molecular weight and an extremely wide molecular weight distribution (Mw / Mn) of 5.0 to 20. Therefore, in order to use it for molding, it is necessary to further perform a step of heating and oxidizing and crosslinking in air to increase the molecular weight, which complicates the process and lowers productivity. Furthermore, the high molecular weight component causes a decrease in fluidity and moldability, and the low molecular weight component has mechanical strength,
This may cause a decrease in chemical resistance and the like.

In order to solve such a problem, various methods described below have been adopted. For example, as a method for reducing by-product salts remaining in a polymer, Japanese Patent Application Laid-Open No. 55-156342 has been proposed. Examples of the method include hot water washing of a polymer disclosed in Japanese Unexamined Patent Publication, and a method of heating a polymer in an aromatic solvent disclosed in Japanese Patent Application Laid-Open No. S59-219331. However, according to these methods, although the sodium content can be reduced, chlorine is contained in the polymer after treatment at about 2000 to 3000 ppm, and no removal effect was observed.

As a method for reducing the chlorine content, Japanese Patent Application Laid-Open No. Sho 62-106929 discloses a method of heating a polymer with an alkali metal salt of a mercapto group-containing compound. Although high-purity polymers can be obtained by this method, the molecular weight distribution was as wide as 6 to 20.

As a typical example of obtaining a high molecular weight polyarylene sulfide, a method of adding a polymerization aid (Japanese Patent Publication No. 52-12240, US Pat. No. 4,038,2)
No. 63), a method for controlling the polymerization temperature and the amount of water in the system (JP-A-61-7332, JP-A-62-149).
No. 725), but they have the drawback that they require a large amount of expensive polymerization aids, increase the polymerization time, increase costs and lower productivity.

On the other hand, as a method for producing a polyarylene sulfide having a narrow molecular weight distribution, a method of washing with an organic polar solvent at a high temperature is disclosed in JP-A-2-182727. However, the polymer obtained by this method is a low molecular weight compound and contains 2000 to 3000 ppm of chlorine, and a method for producing a polyarylene sulfide in which both the molecular weight distribution and the chlorine content are improved has not been established so far. .

Recently, a new method for producing a polyarylene sulfide which has solved these problems has attracted attention. A typical example is a method in which diphenyl disulfide or thiophenol is subjected to cationic oxidation polymerization using a Lewis acid (JP-A-63-21526, JP-A-63-215357). There is a method of carrying out oxidative coupling polymerization of phenol with oxygen using a catalyst in the presence of an acid (JP-A-2-169626). In these methods, unbranched polyphenylene sulfide can be obtained at a high yield under mild conditions.However, the obtained polyphenylene sulfide has a low melting point and is a low molecular weight substance. It is difficult to use. In addition, there are problems such as requiring a large amount of expensive Lewis acid and oxidizing agent and having a long reaction time.
As a result, the production cost is increased, which is industrially disadvantageous.

By the way, poly (phenylene sulfide)
It is known that oligomers can be effectively cured to obtain useful products (US Pat.
046,749). This method is characterized in that heat treatment is performed at a high temperature in the presence of oxygen gas, and the product is partially crosslinked with oxygen. Further, the obtained product not only does not show a definite melting point, but also has poor fluidity, color tone of a molded article, and the like.

On the other hand, a method for producing an engineering plastic by ring-opening polymerization of a cyclic oligomer is generally known. A method for producing nylon 6 by ring-opening polymerization of ε-caprolactam is already known.

Recently, macrocyclic condensation oligomers
Production method, polymerization method and composite material of the obtained polymer
There have been reports on the application of. For example, Polycar
Bonate (ACS Polym. Prepr.30
[2], 569 (1989)), polyarylate (AC
S Polym. Prepr.30[2], 579
(1989)), polyether sulfone (ACS Po)
lym. Prepr.30[2], 581 (198
9)), polyimide siloxane (Macromolec)
ules,23, 4341 (1990); ibid. ,
23, 4514 (1990)), aromatic polyethers
(J. Chem. Soc. Chem. Comm
un. 1990,336); JP-A-3-88828
Information).

[0015]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems and provides a polyarylene sulfide excellent in heat resistance, chemical resistance, various mechanical properties, electrical properties, fluidity, moldability, and the like. In particular, the polyarylene sulfide of various molecular weights in which the proportion of the crosslinked polymer is low, which is essentially linear, has a narrow molecular weight distribution compared to the conventional method, and has a small chlorine content and a small amount of alkali metal, An object of the present invention is to provide a novel method for producing a polyarylene sulfide having such advantages.

[0016]

That is, the present invention relates to Mw
Is 2000 to 500000, the ratio of Mw to Mn (molecular weight distribution) is in the range of 1.1 to 5.0, and the chlorine content is 1
Polyarylene sulfide of 000 ppm or less, and the following general formula (1)

[0017]

Embedded image (Where S represents a sulfur atom, and Ar has 6 to 24 carbon atoms.
R represents 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, a primary, secondary or tertiary amino group.
Ar and R may have the same structure or different structures. Further, n is an integer of 2 to 50, and m is an integer of 0 to 15. ), Wherein the cyclic arylene sulfide oligomer is subjected to ring-opening polymerization in the presence of a ring-opening polymerization catalyst to produce a polyarylene sulfide.

The details will be described below.

The polyarylene sulfide of the present invention has a structure of M
w is in the range of 2000 to 500,000, but Mw is 2
If it is less than 000, the mechanical properties, chemical resistance, etc. are reduced, while if Mw exceeds 500,000, the viscosity is high,
This leads to a decrease in fluidity and moldability.

The molecular weight distribution (Mw / Mn) of the polyarylene sulfide of the present invention is from 1.1 to 5.0, preferably from 1.1 to 4.0. If the molecular weight distribution exceeds 5.0, moldability and mechanical strength will be low.

Further, the chlorine content of the polyarylene sulfide of the present invention is 1000 ppm or less, preferably 50 ppm or less.
It is 0 ppm or less.

Ar in the cyclic arylene sulfide oligomer of the formula (1) used in the present invention is 6 to
An arylene group having 24 carbon atoms and one or more aromatic rings, including phenylene, biphenylene, and naphthalene rings .

R in the above formula (1) represents a methyl group, an ethyl group, a propyl group, a butyl group, a sec-butyl group, a ter
an alkyl group having 1 to 12 carbon atoms such as a t-butyl group, a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group,
An alkoxy group having 1 to 12 carbon atoms such as a butoxy group, sec-butoxy group and tert-butoxy group; an arylene group having 6 to 24 carbon atoms such as phenyl, biphenyl and naphthyl groups; a primary, secondary or tertiary amino group And the like. Among them, a cyclic arylene sulfide oligomer having an alkyl group such as a methyl group and an ethyl group, an alkoxy group such as a methoxy group and an ethoxy group, and an amino group, and an unsubstituted cyclic arylene sulfide oligomer are preferably used.

In the above formula (1), n is an integer of 2 to 50, and is preferably 2 to 3 for solubility in a solvent or lowering the melting point.
5, more preferably 2 to 25.

The polymerizable cyclic arylene sulfide oligomer may be a single compound having a single degree of polymerization or a mixture of cyclic oligomers having different degrees of polymerization. Further, a mixture of cyclic oligomers having different repeating units may be used. Among these, oligomer mixtures having various degrees of polymerization are preferably used because they have a lower melting point than a single compound having a single degree of polymerization.

The cyclic oligomer mixture may contain a compound having a small amount of a linear oligomer or a very small amount of an arylene sulfide unit. Further, these oligomers may contain a linear or cyclic polymer having a low viscosity at a temperature at which the oligomer is liquid.

In the present invention, various ionic compounds are used as a ring-opening polymerization catalyst.

Various metal salts, ammonium salts, phosphonium salts, and the like can be given as ionic compounds that can serve as ring-opening polymerization catalysts in anionic polymerization. For example, monovalent metal, divalent metal monohalide aryl or alkyl, aryl or alkyl oxide, hydroxide, amide, hydride, sulfide, halide, cyanide, carboxylate, carbonate , Hydrogencarbonates, ammonium salts, phosphonium salts or tertiary amines. Among them, an ionic compound represented by the above formula (2) that generates a sulfur anion species and an oxygen anion species is preferable.

R 'in the above formula (2) is a hydrogen atom, an alkyl group having 1 to 12 carbon atoms such as a methyl group, an ethyl group, a propyl group, a butyl group, a sec-butyl group, a tert-butyl group, a methoxy group. Group, ethoxy group, propoxy group, isopropoxy group, butoxy group, sec-butoxy group, ter
An alkoxy group having 1 to 12 carbon atoms such as a t-butoxy group, an arylene group having 6 to 24 carbon atoms such as a phenyl, biphenyl and naphthyl group, a primary, secondary or tertiary amino group, a carboxyl group and esters thereof, nitro Group, cyano group, sulfonic acid group and the like. Among them, a hydrogen atom, a lower alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, a sec-butyl group and a tert-butyl group, a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group,
A lower alkoxy group such as a butoxy group, a sec-butoxy group and a tert-butoxy group, and an amino group are preferred.

R 'is an electron-donating group such as 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, a 1, 2 or tertiary amino group. If it is, the ring-opening polymerization catalyst can be highly activated.

B in the above formula (2) is an organic group having 1 to 24 carbon atoms, but is an arylene group having 6 to 24 carbon atoms or a pyridine, pyrimidine, imidazole, benzimidazole or benzoxazole ring. And B may be a heterocyclic compound such as a benzothiazole ring. Among them, phenylene, biphenylene, naphthalene ring, benzimidazole ring, benzothiazole ring, benzoxazole ring, benzotriazole ring, phthalimide ring and the like which are excellent in stability at high temperature are preferable. More preferred are phenylene, biphenylene, naphthalene ring and benzimidazole ring.

In the above formula (2), D ⁻ is either a sulfur or oxygen anion species, and more preferably a sulfur anion species having high nucleophilicity.

In the above formula (2), M ⁺ is a monovalent metal ion, a divalent metal monohalide ion, an ammonium ion or a phosphonium ion. Metal ions and divalent metal monohalide ions are preferred. Further, by changing the monovalent metal ion and the divalent metal monohalide ion, it is possible to improve the activity and increase the molecular weight of the produced polymer. For example, a ring-opening polymerization catalyst having a metal ion having a small ionic radius such as lithium ion as compared with sodium ion becomes more active, and by using a ring-opening polymerization catalyst having a larger ionic radius such as potassium, the resulting polymer is produced. It is possible to achieve a higher molecular weight.

Examples of the ring-opening polymerization catalyst used in the present invention are shown below, but the present invention is not limited to these.

As ring-opening polymerization catalysts for producing sulfur anion species, thiophenol, 1,2-benzenedithiol,
1,3-benzenedithiol, 1,4-benzenedithiol, 2-thiocresol, 3-thiocresol, 4-
Thiocresol, 2-aminothiophenol, 3-aminothiophenol, 4-aminothiophenol, 2-methoxybenzenethiol, 3-methoxybenzenethiol, 4-methoxybenzenethiol, 4-nitrothiophenol, 4-tert-butyl Thiophenol, 3-
Dimethylaminothiophenol, 4-dimethylaminothiophenol, 2-chlorothiophenol, 3-chlorothiophenol, 4-chlorothiophenol, 2-bromothiophenol, 3-bromothiophenol, 4-bromothiophenol, 4-bromothiophenol tert-butyl-1,2-
Examples thereof include lithium salts such as benzenedithiol, mercaptoimidazole, mercaptobenzimidazole, mercaptobenzoxazole, mercaptobenzothiazole, and mercaptopyrimidine; and alkali metal salts such as sodium salt and potassium salt.

As ring-opening polymerization catalysts for generating oxygen anion species, phenol, 1,2-benzenediol, 1,3
-Benzenediol, 1,4-benzenediol, 2-
Cresol, 3-cresol, 4-cresol, 2-aminophenol, 3-aminophenol, 4-aminophenol, 2-methoxyphenol, 3-methoxyphenol, 4-methoxyphenol, 4-nitrophenol, 4-tert-butylphenol , 3-dimethylaminophenol, 4-dimethylaminophenol, 2-
Examples thereof include lithium salts such as chlorophenol, 3-chlorophenol, 4-chlorophenol, 2-bromophenol, 3-bromophenol and 4-bromophenol, and alkali metal salts such as sodium and potassium salts.

These ring-opening polymerization catalysts which can be used for anionic polymerization may be used alone or in combination of two or more.

Examples of the ionic compound that can serve as a ring-opening polymerization catalyst in cationic polymerization include protonic acids, Lewis acids,
Examples include trialkyloxonium salts, carbonium salts, diazonium salts, ammonium salts, alkylating agents or silylating agents. For example, strong protonic acids such as trichloroacetic acid, trifluoroacetic acid, trichlorosulfonic acid, trifluorosulfonic acid, etc., boron trifluoride, aluminum chloride, aluminum bromide, titanium tetrachloride, tin dichloride, tin tetrachloride, pentafluoride Lewis acids such as antimony bromide, antimony pentachloride and iron (III) chloride; trialkyloxonium salts such as trimethyloxonium tetrafluoroborate and triethyloxonium tetrafluoroborate; triphenylcarbonium hexafluorophosphate; triphenylcarbo Carbonium salts such as sodium tetrafluoroborate, triphenylcarbonium hexachloroantimonate, diphenyldiazonium tetrafluoroborate, 4-chlorobenzenediazonium hexafluorophosphate, Diaryldiazonium salts such as nitrobenzenediazonium tetrafluoroborate, sulfates such as monomethyl sulfate, dimethyl sulfate, and trifluoromethyl sulfate; sulfonates such as methyl trifluoromethanesulfonate and trimethylsilyl trifluoromethanesulfonate; and methyl trifluoroacetate. An acetic acid ester etc. can be mentioned. Among them, preferred are diaryldiazonium salts having high stability at high temperatures, and trifluoromethanesulfonic acid esters which act as strong alkylating agents for sulfur.

These ring-opening polymerization catalysts that can be used for the cationic polymerization may be used alone or in a combination of two or more.

The concentration of the ring-opening polymerization catalyst used depends on the molecular weight of the target polyarylene sulfide and the type of the ring-opening polymerization catalyst, but is usually 0.001 to 20% by weight, preferably 0 to 20% by weight, based on the cyclic oligomer. .005-
It is 15% by weight, more preferably 0.01 to 10% by weight.

When the ring-opening polymerization catalyst is added, it may be added as it is. Alternatively, the cyclic oligomer is dissolved in an appropriate solvent, preferably methylene chloride, and a predetermined amount of the ring-opening polymerization catalyst is added thereto. A method of removing the solvent may be employed.

It is essential that the temperature used in the ring-opening polymerization of the present invention is not higher than the melting temperature of the cyclic oligomer mixture and the decomposition temperature of the ring-opening polymerization catalyst and the cyclic oligomer used. Further, when the polymerization temperature is too high, the possibility of side reactions such as a curing reaction of the cyclic oligomer increases. Usually 1
It is in the range of 50 to 400 ° C, preferably in the range of 180 to 370 ° C, and more preferably in the range of 200 to 350 ° C.

The reaction time varies depending on the type of the ring-opening polymerization catalyst to be used, the polymerization temperature and the like, but it is preferable to set the conditions so as to suppress the curing reaction as much as possible, and usually in the range of 0.1 to 100 hours. It is preferred to do so.

The above-mentioned polymerization may be carried out in a usual polymerization reactor, in a mold for producing a molded product, or in an extrusion for producing polyarylene sulfide as an extrudate. The polymerization may be performed in the machine.

This polymerization is usually carried out in the absence of a solvent, but can be carried out in the presence of a solvent. As the solvent, any solvent may be used as long as it does not lose the polymerization activity.
Usually, it is preferable to dissolve the cyclic oligomer and the ring-opening polymerization catalyst and not to deactivate the ring-opening polymerization catalyst.

Suitable solvents for anionic polymerization include 1,3-dimethyl-2-imidazolidinone, hexamethylphosphoric triamide, diphenylsulfone,
Examples include diphenyl ether, benzophenone, dimethylacetamide, N-methyl-2-pyrrolidone, N-cyclohexyl-2-pyrrolidone, m-cresol and the like. In addition, solvents generally used in anionic polymerization can also be used.

As a suitable solvent in the cationic polymerization,
Examples include methylene chloride, chloroform, dichloroethane, dibromoethane, nitromethane, nitroethane, nitrobenzene, o-dichlorobenzene, 1-chloronaphthalene, and the like, and other solvents generally used in cationic polymerization can also be used.

These solvents may be used alone or as a mixture of two or more.

The polymerization temperature when using these solvents is as follows:
Although it depends on the solvent used, it is in the range of −78 to 400 ° C., and from the viewpoint of the solubility of the cyclic oligomer and the like is −20 to 35.
Preferably it is in the range of 0 ° C.

The polyarylene sulfide such as the polyphenylene sulfide obtained in the present invention is excellent in heat resistance, chemical resistance, various mechanical properties, and electrical properties. In particular, since the chlorine content and the alkali metal salt abundance, which have conventionally been problems, are much smaller than those of the conventional method, the electrical properties are remarkably excellent. In addition, the crosslinked polymer has an extremely low proportion, is essentially linear and has a narrow molecular weight distribution, and thus has the advantage of excellent fluidity and moldability. Further, in the present invention, by adjusting the amount of the ring-opening polymerization catalyst used, it is possible to adjust the molecular weight of the polyarylene sulfide, usually a higher molecular weight than the polyarylene sulfide obtained by polycondensation, the molecular weight distribution. A narrow polyarylene sulfide can be easily obtained.

The polyarylene sulfide obtained as described above can be melt-mixed with various polymers, and the improvement of the physical properties as a polymer alloy is expected.

Specific examples of blendable polymers include polyethylene, polybutadiene, polyisoprene,
Polychloroprene, polystyrene, polybutene, poly α
-Methylstyrene, polyvinyl acetate, polyvinyl chloride,
Polyacrylate, polymethacrylate,
Polyamides such as polyacrylonitrile, nylon 6, nylon 66, nylon 610, nylon 12, nylon 11, nylon 46, polyethylene terephthalate,
Polyester such as polybutylene terephthalate and polyarylate, polyurethane, polyacetal, polycarbonate, polyphenylene oxide, polysulfone, polyether sulfone, polyallyl sulfone, polyphenylene sulfide sulfone, polyether ketone, polyether ether ketone, polyphenylene sulfide ketone, polyimide, polyamide imide , An epoxy resin, a silicone resin, a phenoxy resin, a fluororesin, and other homopolymers, random or block, graft copolymers, and mixtures thereof.

If necessary, reinforcing fillers such as glass fibers, carbon fibers, alumina fibers and other ceramic fibers, aramid fibers, wholly aromatic polyester fibers, metal fibers, potassium titanate whiskers, calcium carbonate, mica, Talc, silica, barium sulfate, calcium sulfate, kaolin, clay, pyroferrite, bentonite, sericanite, zeolite, nepheline sinite, attapulgite, wollastonite, ferrite, calcium silicate, magnesium carbonate, dolomite, antimony trioxide, zinc oxide , Titanium oxide, magnesium oxide, iron oxide, molybdenum disulfide, graphite, gypsum, glass beads, glass powder, glass balloon,
Inorganic fillers such as quartz and quartz glass, and organic and inorganic pigments can also be blended.

Also, release agents, silane-based and titanate-based coupling agents, lubricants, heat stabilizers, weathering stabilizers, crystal nucleating agents, foaming agents, rust inhibitors, ion trapping agents, flame retardants,
A flame retardant aid or the like may be added as necessary.

As described above, the polyarylene sulfide obtained by the above-described production method is used alone or in combination with the above-mentioned polymer, reinforcing filler, inorganic filler and the like, and is subjected to injection molding.
It can be molded into various molded products, films, sheets, pipes, fibers, etc. by extrusion molding.

[0056]

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

The cyclic oligomer mixture used in each of the examples was a cyclic phenylene sulfide oligomer having a degree of polymerization of 7 to 15 and containing substantially no linear phenylene sulfide oligomer. The molecular weight was calculated by gel permeation chromatography (GPC) in terms of polystyrene. GPC measurement conditions are shown below.

Eluent: 1-chloronaphthalene Temperature: 210 ° C. Detector: UV detector 360 nm Flow rate: 1.0 ml / min Injection volume: 200 μl (slurry: 0.2% by weight) Melting point: DSC (manufactured by Seiko Denshi) ), Kept at 340 ° C for 5 minutes, cooled to 50 ° C, and heated at a rate of 10 ° C /
Measured in minutes.

The melt viscosity was measured using a Koka type flow tester at 300 ° C., a load of 10 kg, a die diameter of 0.5 mm,
It measured using the dice of length = 2.0mm.

Reference Example 1 (Recovery method of cyclic phenylene sulfide oligomer) The cyclic phenylene sulfide oligomer used in each Example was recovered by the following operation.

A 15-liter reactor equipped with a stirrer, dehydration tower and jacket was charged with N-methyl-2-pyrrolidone (N
MP) and sodium sulfide (purity: Na ₂ S 6
(187%) was heated with a jacket under stirring, and dehydrated through a dehydration tower until the internal temperature reached about 205 ° C. At this time, 420 g of an effluent mainly composed of water was distilled off. Next, 2153 g of p-dichlorobenzene was added, and the mixture was heated to 250 ° C. and reacted for 3 hours. After completion of the reaction, the reaction mixture was cooled to about 100 ° C., and the inside of the reactor was depressurized and then reheated, thereby distilling off 5200 g of an effluent mainly composed of NMP through a dehydration tower. The pressure in the reactor system was returned to normal pressure, 8 liters of water was added to form a water slurry, and the mixture was heated and stirred at 80 ° C. for 15 minutes. . Further, the polymer was returned to the reactor, 8 l of water was added, and the mixture was heated and stirred at 180 ° C. for 30 minutes. After cooling, the water slurry was taken out from the outlet at the bottom of the reactor and centrifuged to collect the polymer. The resulting polymer was transferred to a jacketed ribbon blender and dried. The resulting polymer weighed 1450 g and had a melt viscosity of 240 poise.

Next, this polyphenylene sulfide 2
Soxhlet extraction was performed using 00 g of methylene chloride as a solvent. Thereafter, the saturated methylene chloride extract was poured into methanol, and the precipitate was filtered and dried to obtain 1.2 g of a cyclic phenylene sulfide oligomer mixture. From the results of mass spectrometry and high performance liquid chromatography, it was confirmed that this cyclic oligomer mixture was a cyclic phenylene sulfide oligomer of substantially 7 to 15 mer. Melting point was 260 ° C.

Example 1 540 mg of cyclic phenylene sulfide oligomer obtained in Reference Example 1 and sodium salt of thiophenol 1.8
mg (0.3% by weight) was charged into a 10 ml polymerization test tube, and after purging with nitrogen, the tube was sealed under reduced pressure and immersed in a 300 ° C. molten salt bath for 30 minutes. After cooling the obtained off-white product to room temperature, it was pulverized and redissolved in 250 ml of 1-chloronaphthalene at 230 ° C. Upon cooling to room temperature, a white precipitate was obtained. The precipitate was filtered, washed (methylene chloride, methanol) and dried to obtain 430 mg of a white powder. The yield was 80% and the melting point was 285 ° C. The weight average molecular weight of the obtained polymer was 61,000, and the molecular weight distribution was 2.2.

The results of the elemental analysis are shown below. Compared with polyphenylene sulfide obtained by conventional polycondensation, Na, Cl
It can be seen that the content has decreased.

Elemental analysis result: Actual measured value (calculated value) ─────────────────── C: 66.6% (66.6%) H: 3.5% (3.7%) S: 30.1% (29.6%) N: 0% (0%) Na: 200 ppm Cl: 440 ppm Examples 2 to 4 Thiophenol used as a ring-opening polymerization catalyst in Example 1 The polymerization was carried out under the same conditions as in Example 1 except that the amount of the sodium salt was changed to 0.7, 1.3, 3.1% by weight based on the amount of the cyclic phenylene sulfide oligomer. In each case, a white powder was obtained with a yield of about 80%. Table 1
As shown in the figure, the weight average molecular weight was 15,000 to 5,000.
A polymer of 0 was obtained.

Example 5 In place of the sodium salt of thiophenol used as a ring-opening polymerization catalyst in Example 1, 1.7% by weight of sodium salt of 4-tert-butylthiophenol was used. Polymerization was performed under the same conditions as in Example 1. Table 1 shows the results
Shown in

Examples 6 and 7 In place of the sodium salt of thiophenol used as a ring-opening polymerization catalyst in Example 1, lithium salt and potassium salt of thiophenol were used at 1.1 and 1.4% by weight, respectively. The polymerization was carried out under the same conditions as in Example 1. Table 1 shows the results.

Example 8 After dissolving 540 mg of the cyclic phenylene sulfide oligomer obtained in Reference Example 1 in 10 ml of 1,3-dimethyl-2-imidazolidinone, 7.3 mg of the sodium salt of thiophenol was added, and a nitrogen stream was added. Below, 6 at 250 ° C
Allowed to react for hours. Thereafter, the mixture was cooled to room temperature, and the deposited precipitate was filtered, washed (methylene chloride, methanol), and dried to obtain a white powder. The yield was 39% and the melting point was 285 ° C.

Example 9 After dissolving 540 mg of a cyclic phenylene sulfide oligomer in 10 ml of a methylene chloride solution, 0.0057 ml of methyl trifluoromethanesulfonate was added, and the mixture was stirred at 25 ° C. for 24 hours under a nitrogen stream. The precipitate deposited during the reaction was filtered, washed (methylene chloride, methanol), and dried to obtain a white powder. The yield was 33% and the melting point was 270 ° C.

[0070]

[Table 1] Comparative Example 1 Polyphenylene sulfide was obtained in the same manner as in Reference Example 1. The resulting polyphenylene sulfide has a melting point of 280.
C., the weight average molecular weight was 28,000, but the polymer was found to have a broad molecular weight distribution of 6.8. Further, as a result of elemental analysis, the Na content was 1300 ppm, and the Cl content was 2200 ppm, and Na and C were larger than those in the above example.
l was present.

Comparative Example 2 540 mg of the cyclic phenylene sulfide oligomer obtained in Reference Example 1 was subjected to the same conditions as in Example 1 in the absence of a ring-opening polymerization catalyst. The resulting black product is 230
It was a crosslinked polymer partially insoluble in 1-chloronaphthalene at ℃. The 1-chloronaphthalene soluble matter also has a melting point of 26.
The polymer exhibited a temperature of 5 ° C. and was highly crosslinked.

[0072]

As is clear from the above description, according to the present invention, the proportion of the crosslinked polymer is low, it is essentially linear, and its chlorine content and alkali metal content are lower than those of the conventional method. Polyarylene sulfides of various molecular weights having a small amount and a narrow molecular weight distribution can be easily obtained.

Claims (5)

(57) [Claims] 1. A following general formula (1) ## STR1 ## (Where S represents a sulfur atom, and Ar has 6 to 24 carbon atoms.
R represents 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, a primary, secondary or tertiary amino group.
Ar and R may have the same structure or different structures. Further, n is an integer of 2 to 50, and m is an integer of 0 to 15. A) a method for producing a polyarylene sulfide, which comprises subjecting the cyclic arylene sulfide oligomer represented by the formula (1) to a ring-opening polymerization in the presence of a ring-opening polymerization catalyst. 2. The ring-opening polymerization catalyst is represented by the following general formula (2): (R ') _p- B- (D ^- M ⁺ ) _q (2) (where R' is a hydrogen atom and has 1 to 12 carbon atoms). Represents an alkyl group, an alkoxy group having 1 to 12 carbon atoms, an arylene group having 6 to 24 carbon atoms, a primary, secondary or tertiary amino group, a carboxyl group and its ester, a cyano group, a sulfonic acid group, and a halogen atom. , B represents an organic group having 1 to 24 carbon atoms, D ⁻ represents a sulfur anion species , and M ⁺ represents a monovalent metal ion, a divalent metal monohalide ion, an ammonium ion, or a phosphonium ion. , P is 0
An integer of 15 and q is an integer of 1 to 15. 2. The method for producing a polyarylene sulfide according to claim 1 , wherein the compound is an ionic compound represented by the formula: 3. The method for producing a polyarylene sulfide according to claim 2 , wherein a ring-opening polymerization catalyst wherein R ′ in the general formula (2) is an electron donating group is used. 4. A ring-opening polymerization catalyst comprising a protonic acid, a Lewis acid,
The method for producing a polyarylene sulfide according to claim 1 , wherein the method is a cationic polymerization catalyst selected from a trialkyloxonium salt, a carbonium salt, a diazonium salt, an ammonium salt, an alkylating agent and a silylating agent. 5. The general formula (1) according to any one of claims 1 to 4, characterized in that in the solvent under the presence not abolished the ring-opening polymerization of a polymerization activity of cyclic arylene sulfide oligomer represented A method for producing polyarylene sulfide.