JPH05178994A - Polyarylene sulfide, production thereof, and apparatus therefor - Google Patents

Abstract

PURPOSE:To provide the title sulfide which is substantially free from heavy metals. CONSTITUTION:An alkali metal sulfide is reacted with a dihaloaromatic compound in a polar aprotic solvent to produce the title sulfide. The reaction is performed using an apparatus made of chromium having a relative density of at least 95% and a purity as high as at least 99.7% at least at a portion where the apparatus contacts liquid, so that the sulfide is substantially free from heavy metals. The invention also provides an apparatus for producing the title sulfide, which is characterized by comprising chromium having a relative density of at least 95% and a purity as high as at least 99.7%. Thus, the title sulfide which is excellent in thermal stability and whiteness is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a polyarylen sulfide (hereinafter abbreviated as PAS) substantially free of heavy metals and a polyaryene sulfide by reacting an alkali metal sulfide with a dihaloaromatic compound in a polar aprotic solvent. The present invention relates to a method for producing len sulfide and a manufacturing device for producing the same.

[0002]

2. Description of the Related Art In recent years, PAS has been attracting attention as a member for electric and electronic equipment and a member for automobile equipment by taking advantage of its excellent heat resistance and chemical resistance. Further, it can be molded into various molded parts, films, sheets, fibers and the like by injection molding and extrusion molding, and is used in a wide range of fields. In these fields of application, PAS of extremely high purity is required.

As a typical method for producing PAS, a method by a reaction of an alkali metal sulfide and an aromatic halide, for example, a general-purpose austenitic stainless steel (for example, SUS304, SUS316) equipment is used.
Examples thereof include a method of reacting a hydrous alkali metal sulfide with a dihaloaromatic compound in an aprotic polar organic solvent. At this time, since the alkali metal halide salt formed together with PAS is soluble in a solvent such as water, it is not possible to remove PAS during a treatment such as phase separation, extraction and washing using a solvent such as water. It is possible. However, the conventional PA described above
In the method of producing S, in the course of the reaction, sulfide used as a part of the reaction raw material reacts with the material of the reactor to produce metal sulfide (iron sulfide, nickel sulfide, etc.). This by-product metal sulfide is insoluble in the solvent, and thus is hardly removed by the subsequent processing steps, and remains in the produced PAS inevitably. The PAS containing such a metal sulfide is inferior in surface smoothness and electric characteristics, so that it is required to have a high function, for example, its use as a base material of a magnetic recording material is limited.

Further, when the heavy metal sulfide is mixed, not only the color tone of the product is changed, but also the PAS produced under such an environment has a problem that the thermal stability is poor. Titanium (Ti) is a solution to these problems.
There has been proposed a method for manufacturing PAS using a device comprising (Japanese Patent Application Laid-Open No. 61-23627). However,
When Ti equipment is used, although there is no mixture of iron, chromium and nickel sulfides in the same product (PAS) as when using conventional stainless steel equipment, T
The i component is mixed, which causes a bad influence on the electrical characteristics. As described above, it has been impossible to produce a PAS containing substantially no heavy metal by the conventional technique.

In addition, PAS when using equipment made of Ti
Although the amount of oligomers in the product is slightly improved as compared with the case of using general-purpose austenitic stainless steel, it has not been a fundamental solution.

Furthermore, in the conventional equipment, corrosion occurs in places where PAS is likely to adhere during the PAS treatment process, such as dehydration tanks, refining tanks and transportation pipes, making stable operation impossible for a long period of time. It was

[0007]

DISCLOSURE OF THE INVENTION The present invention comprises an extremely high-purity chromium material in the production of PAS by reacting an alkali metal sulfide with a dihaloaromatic compound in a polar aprotic solvent. By using the apparatus, the above-mentioned drawbacks of the prior art are substantially eliminated from heavy metal PAS, as well as excellent corrosion resistance and durability in the production of PAS, and corrosion cracking does not occur even in the heat-affected zone. A PAS manufacturing device is provided.

[0008]

That is, according to the present invention, a PAS containing substantially no heavy metal is provided by a device using a high-purity chromium material having a relative density of 95% or more and a purity of 99.7% or more in at least the liquid contact part. Related to manufacturing
The details will be described below.

The PAS of the present invention is characterized in that it does not substantially contain heavy metals. The heavy metal here is
A metal with a specific gravity of 4.0 or more, such as iron, manganese,
Examples include chromium, copper, lead, molybdenum, cobalt, nickel and titanium. In addition, the term "substantially free of heavy metal" means that the content of heavy metal in PAS is 10 relative to PAS.
It means less than or equal to ppm, preferably less than or equal to 5 ppm, and more preferably less than 0.5 ppm.

In the PAS of the present invention, the aromatic residue has a thioe group.
It is a polymer linked through a tel bond and means a polymer mainly having a repeating unit represented by the following general formulas (1) to (6).

[0011]

[Chemical 1]

[0012]

[Chemical 2]

[0013]

[Chemical 3]

[0014]

[Chemical 4]

[0015]

[Chemical 5]

[0016]

[Chemical 6] (Where Y is -R, -OR, -OM, -COOR,-
_COOM, -NR 2, -CONR _2, or -CN {R represents hydrogen, an alkyl group having 1 to 24 carbon atoms, a cycloalkyl group having 6 to 24 carbon atoms, ants - a group or aralkyl group,
M is an alkali metal}, and X is -CO-, -C
ONR ^1- , -O-, -S-, -SO-, -SO _2- ,
—CR ² R ³ — or —SiR ² R ³ — {R ¹ R ² R ³ is hydrogen, an alkyl group having 1 to 24 carbon atoms, a cycloalkyl group having 6 to 24 carbon atoms, an aryl group or an aralkyl group. A), a is an integer of 0 to 4, b is an integer of 0 to 2, c
Is an integer of 0 to 4, d is an integer of 0 to 3, e is an integer of 0 to 3, f is an integer of 0 to 3, g is an integer of 0 to 5, h is 0 to 4
Is an integer, i is an integer of 0 to 4, j is an integer of 0 to 4, and k is 0.
Is an integer of 4 and n is an integer of 1 to 3. ) PA of the present invention
S may be a polymer containing a single repeating unit as shown in Chemical formulas 1 to 6 or a polymer containing a plurality of repeating units. When S contains a plurality of repeating units, it may be a random copolymer. It may be a block copolymer. Further, the PAS of the present invention, even if linear, has a branched or crosslinked structure such as PAS obtained by copolymerizing a polyhaloaromatic compound containing three or more halogens, or by heat curing in air. May be

Some examples of such PAS are poly (p-phenylene sulfide) and Indian Journal of Chemistry as disclosed in JP-B-45-3368 and JP-B-52-12240. -, 21, 501 (1982), polyphenylene sulfide ketone, as disclosed in JP-B-53-25.
Polyphenylene sulfide sulfone as disclosed in Japanese Patent Publication No. 880, polybiphenylene sulfide as disclosed in Japanese Patent Publication No. 45-3368, and polyphenylene sulfide amide as disclosed in Japanese Patent Laid-Open No. 63-83135. Etc.

The PAS of the present invention is 10,000 to 5000.
Those having a weight average molecular weight of 00 are preferably used. The weight average molecular weight here is measured by using a gel permeation chromatograph (hereinafter abbreviated as GPC). For example, in the case of poly (p-phenylene sulfide), 1-chloronaphthalene is used as a solvent, 210
It can be determined by measuring at ° C.

Next, the PAS manufacturing method of the present invention will be described in detail below. The method for producing PAS according to the present invention is such that, at the time of producing PAS by reacting an alkali metal sulfide with a dihaloaromatic compound in a polar aprotic solvent, at least the liquid contact portion has a relative density of 95% or more and a purity of 9
It is characterized in that it is manufactured using an apparatus composed of high-purity chrome of 9.7% or more.

It is essential that the high-purity chromium material has a relative density of 95% or more. If the relative density is less than 95%, sufficient strength, workability and corrosion resistance cannot be expected. At the same time, it is essential that the purity of the metallic chromium constituting the present invention is 99.7% or more, and if the purity is lower than the above, that is, metallic chromium with a large amount of impurities has poor workability, it is difficult to roll. Cracking occurs and material deterioration due to welding becomes significant. The relative density referred to here is calculated from the measured value of the density measured by an ordinary method and the theoretical density of chromium using the following formula.

Relative density (%) = (measured value of density / theoretical density) × 100 Further, in the present invention, in addition to the above-mentioned conditions, the tensile strength of the chromium rolled plate is preferably 20 kg / mm ² or more.

The corrosion resistant material of the present invention can be used in place of the materials conventionally used for tanks, reactors, heat exchangers, pipes and the like. Furthermore, the characteristic feature is that the material of the present invention can be used as a clad or a lining material, which has been impossible with the conventional high chromium alloys due to the problem of workability.

In the method for producing the corrosion-resistant material of the present invention, high-purity metallic chromium powder (99.7% or more) is preferable as a starting material, and such high-purity metallic chromium powder is electrolyzed from a chromium salt solution. The obtained metallic chromium or chromium salt solution is purified by a solvent extraction method, the obtained chromium salt solution or the chromium salt obtained from this solution is oxidized, and further reduced by a hydrogen reduction method or the like to grind the metallic chromium obtained. It is obtained by doing. The metal chrome powder thus obtained is enclosed in, for example, a sealed container having vacuum resistance and heat resistance. Although the material and shape of this container are not strictly limited, a stainless steel or copper container is used in view of economy. Also,
The shape of this container is appropriately determined according to the desired shape of the rolled body. In this method, the metal powder is sealed in a sealed container, and then 10
After evacuating to ^-5 mmHg or less, 600 ~
Hot groove roll rolling is performed at 1000 ° C. Groove type low
The rolling mill may be a general-purpose one, but a two-high rolling mill is usually used. In this temperature range, the solid solubility of nitrogen in metallic chromium is as low as 3 to 17 ppm, which is preferable. In addition, the rolling rate is 5
By setting the content to 0 to 80%, a molded product having a dense structure can be obtained. Slow cooling is preferable for cooling the rolled body after heating and rolling. This is because if this cooling is rapidly cooled, uneven thermal stress is applied to the internal chromium alloy structure, and cracks may occur. Next, the obtained rolling body is 800-1000.
The structure is homogenized and softened by annealing at ℃. The annealing time is not particularly limited, but is usually 1 hour or more.

The corrosion resistant material of the present invention can be obtained by such a method, but the production method is not limited to this method, and an ingot is produced by using various melting methods such as a high frequency atmosphere furnace or a high frequency arc furnace. It is also possible to manufacture and use plastic working such as hot rolling.

Next, P using the equipment made of the above materials
The outline of the AS manufacturing process will be described. The manufacturing method and manufacturing process of the PAS targeted by the present invention are described in, for example, Japanese Patent Publication No.
It can be carried out by a known method as disclosed in JP-A-5-3368, and can be produced by reacting an alkali metal sulfide with a dihaloaromatic compound in a polar aprotic solvent.

Alkali metal sulfides used here include lithium sulfide, sodium sulfide, potassium sulfide,
Mention may be made of rubidium sulphide, cesium sulphide and mixtures thereof, which may be used in anhydrous or hydrated form. These alkali metal sulfides are
It can be obtained by reacting an alkali metal hydrosulfide with an alkali metal base or hydrogen sulfide with an alkali metal base, and may be prepared in situ prior to the addition of the dihaloaromatic compound into the polymerization system, or outside the system. It does not matter if you use the one prepared in. Among the above alkali metal sulfides, sodium sulfide is preferable for use in the present invention, and sodium sulfide hydrate having a purity of 60% and Na ₂ S.5H ₂ O, which are commercially available products, as well as Na ₂ S.9H. Anhydrous Na ₂ S prepared by heating a hydrate such as ₂ O under reduced pressure
(U.S. Pat. No. 2,533,163) and Japanese Patent Laid-Open No. 64-28.
The anhydrous sodium sulfide single crystal disclosed in Japanese Patent No. 207 is also preferably used.

The amount of coexisting water in the system when the dihaloaromatic compound is added for the polymerization is preferably set to about 4 mol or less per 1 mol of the alkali metal sulfide, and the amount of the coexisting water in the system is reduced by distillation during the polymerization. It is also possible to change the amount of water.

Examples of the dihalo aromatic compound include p-dichlorobenzene, m-dichlorobenzene, o-dichlorobenzene, p-dibromobenzene, p-diiodobenzene,
Dichloronaphthalene, dibromonaphthalene, dichlorodiphenyl sulfone, dichlorobenzophenone, dichlorodiphenyl ether, dichlorodiphenyl sulfide,
Examples thereof include dichlorodiphenyl, dibromodiphenyl, dichlorodiphenyl sulfoxide, 2,6-dichlorobenzonitrile, 1,4-N, N ′-(bis-4-chlorophenylcarbamoyl) benzene, and the like, and mixtures thereof. -Dihalobenzenes are preferred, especially p-dichlorobenzene. Further, a polyhaloaromatic compound containing three or more halogens in one molecule, for example, trichlorobenzene, tribromobenzene, triiodobenzene, tetrachlorobenzene, trichloronaphthalene, tetrachloronaphthalene and the like can be used in combination.

The polymerization solvent is preferably a polar solvent, particularly preferably an aprotic solvent which is stable to alkali at high temperature. For example, N, N-dimethylacetamide,
N, N-dimethylformamide, hexamethylphosphoramide, N-methyl-ε-caprolactam, N-ethyl-2-pyrrolidone, N-methyl-2-pyrrolidone (hereinafter abbreviated as NMP), 1,3-dimethylimidazo Examples thereof include ridinone, dimethyl sulfoxide, sulfolane, tetramethyl urea and the like, and mixtures thereof.

The polymerization is carried out at 200 to 300 ° C., preferably 22
0.5 to 3 hours at 0 to 280 ° C., preferably 1 to 15
It is carried out with stirring for an hour.

The amounts of the alkali metal sulfide and the dihalo aromatic compound used in the present invention are molar ratios of (alkali metal sulfide) :( dihalo aromatic compound) = 1.0.
The range of 0: 0.90 to 1.10 is preferred and the amount of polar aprotic solvent used is the PA produced by the polymerization.
It can be used in the range of S of 3 to 60% by weight, preferably 7 to 40% by weight.

Many methods are already known for producing PAS by reacting a hydrous alkali metal sulfide with a dihaloaromatic compound in such a polar aprotic organic solvent, and the present invention is a relative method. Density of 95% or more,
These methods can be used except that an apparatus made of high-purity chromium having a purity of 99.7% or more is used, and there is no particular limitation.

If necessary, the PAS obtained as described above may include glass fibers, carbon fibers, ceramic fibers such as alumina fibers, aramid fibers, wholly aromatic polyester fibers, metal fibers, potassium titanate whiskers, etc. Reinforcing filler and calcium carbonate, mica, talc, silica, barium sulfate, calcium sulfate, kaolin, clay, pyroferrite, bentonite, sericite, zeolite, nepheline sinite, attapulgite, wollastonite, PMF, 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, quartz, quartz glass, etc. Inorganic fillers and organic and inorganic pigments It can also be formulated.

As the glass fiber, for example, a fiber length of 1.5
.About.12 mm, chopped strands having a fiber diameter of 3 to 24 .mu.m, milled fibers having a fiber diameter of 3 to 8 .mu.m, and glass flakes and glass powders of 325 mesh or less.

Further, a plasticizer such as an aromatic hydroxy derivative, a mold release agent, a silane-based or titanate-based coupling agent, a lubricant, a heat resistance stabilizer, a weather resistance stabilizer, a crystal nucleating agent, a foaming agent, and a rust preventive agent. Agents, ion trap agents, flame retardants, flame retardant aids, etc. may be added as necessary.

Further, if necessary, thermoplastic elastomer such as olefin type, styrene type, urethane type, ester type, fluorine type, amide type, acrylic type, polyethylene, polypropylene, polybutadiene, polyisoprene, polychloroprene, polybutene, Rubber components such as styrene butadiene rubber and its hydrogenated product, acrylonitrile butadiene rubber, ethylene propylene copolymer, ethylene propylene ethylidene norbornene copolymer, nylon 6, nylon 66, nylon 610, nylon 12,
Polyamide resins such as nylon 11 and nylon 46, polyethylene terephthalate, polybutylene terephthalate
, Polyester resins such as polyarylates, polystyrene, poly α-methylstyrene, polyvinyl acetate, polyvinyl chloride, polyacrylic acid ester, polymethacrylic acid ester, polyacrylonitrile, polyolefin,
Polyurethane, polyacetal, polycarbonate, polyphenylene oxide, polysulfone, polyethersulfone, polyallylsulfone, polyphenylene sulfide sulfone, polyetheretherketone, polyetheretherketone, polyphenylene sulfide ketone, polyamideimide, silicone resin A homopolymer such as a phenoxy resin, a fluororesin and a melt-processable resin forming an anisotropic melt phase, a random or block, a graft copolymer and a mixture thereof or a modified product thereof may be added.

The PAS manufacturing equipment referred to in the present invention is
It means a reactor, an evaporator, a dehydration tank, a refining tower, a transportation pipe, a storage tank, etc. used in the PAS manufacturing process.

[0038]

EFFECTS OF THE INVENTION According to the present invention, PAS having extremely high purity and reduced amount of oligomer can be obtained because heavy metal contamination resulting from corrosion of equipment materials is released. Therefore, in injection molded products and extruded products,
A molded product having excellent thermal stability and electrical properties can be obtained. In addition, when formed into a film, a film having excellent color tone and thermal stability as well as surface smoothness and electrical characteristics can be obtained. Furthermore, when a fiber is used, a fiber having excellent color tone and thermal stability as well as strength can be obtained.

As described above, the PAS of the present invention is substantially free of heavy metals, and therefore its utility value is extremely high.

Further, since the PAS manufacturing apparatus of the present invention is extremely excellent in corrosion resistance even under the extremely corrosive PAS manufacturing condition which is a problem with conventional materials such as stainless steel, Ti or chrome plating. The life of the device can be extended.

[0041]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

Among the PASs produced in the following Examples and Comparative Examples, the molecular weight of poly (p-phenylene sulfide) (hereinafter abbreviated as PPS) was 1-chloronaphthalene as a solvent and UV detection as a detector. High temperature G equipped with a vessel
It was measured with a PC at 210 ° C. and calculated from a calibration curve of standard polystyrene.

On the other hand, the molecular weight of polyphenylene sulfide ketone (hereinafter abbreviated as PPSK) is p-
Using a mixed solvent of chlorophenol and chloroform (15:85 by weight ratio), measurement was carried out at room temperature with a GPC equipped with an RI detector as a detector, and the value was calculated from a calibration curve of standard polystyrene.

The molecular weight of polyphenylene sulfide sulfone (hereinafter abbreviated as PPSS) is detected by using a mixed solvent of phenol and 1,1,2,2-tetrachloroethane (weight ratio 3: 2) as a solvent. It was measured at room temperature with a GPC equipped with an RI detector as a container, and calculated from a calibration curve of standard polystyrene.

Example 1 and Comparative Example 1 Corrosion resistant materials (Nos. 1 to 3) and comparative materials (Nos. 4 to 7) of the present invention having the composition, relative density and tensile strength shown in Table 1.
Was prepared by the following manufacturing method.

Chromium metal powder having a purity of 99.7% or more was mixed with the composition shown in Table 1, sealed in a stainless steel hermetically sealed container and evacuated to 10 ^-5 mmHg. Next, hot groove roll rolling was performed at 800 ° C. and 70% rolling, and the obtained rolled body was annealed at 1000 ° C. for 1 hour. After this, a test piece having a size of 2 cm × 3 cm was processed. In addition, the comparative material shown in Table 2, that is, SUS304
(No. 7) and Ti (No. 6) were processed into a test piece with a size of 2 cm × 3 cm. The balance of the composition is other impurity components.

This test piece is made of SUS31 having a capacity of 2 liters.
It was attached to an autoclave manufactured by No. 6 and polymerized under the following conditions.

Na ₂ S.2.9H ₂ O on the autoclave
2.45 mol of NMP (600 ml) was added, the mixture was stirred under a nitrogen stream, heated to 200 ° C., and 90.8 ml of a distillate mainly composed of water was distilled off. Then, the system was cooled to 170 ° C., and 2.4 mol of p-dichlorobenzene was added to NMP of 200 m.
It is added together with 1, and the system is sealed under a nitrogen stream and heated to 2
Polymerization was carried out at 50 ° C. for 3 hours.

After completion of the polymerization, the system was cooled and the reaction product was taken out. After repeating the same operation 10 times, the test piece was taken out from the system and the corrosion rate was measured.
Shown in.

As is clear from the table, the corrosion of the equipment materials (Nos. 1 to 3) of the present invention was below the detection limit and showed remarkable corrosion resistance and durability. On the other hand, even chromium which has a low purity (No. 5) has low corrosion resistance, and one having a low relative density (No. 4) has cracks after the test. Furthermore, the known materials (Nos. 6 to 7) were found to have local corrosion, and were found to be unsuitable as equipment materials.

[0051]

[Table 1]

[0052]

[Table 2]

[0053]

[Table 3] Example 2 Using an anhydrous sodium sulfide single crystal obtained by the same method as disclosed in JP-A-64-28207, the corrosion rate was measured in the same manner as in Example 1.

No. 1 in Table 1 A test piece (2 cm × 3 cm) of the material shown in 1 was attached to a 2 l capacity SUS316 autoclave, and polymerization was performed under the following conditions.

2.45 mol of anhydrous Na ₂ S single crystal (purity 99.42%), p-dichlorobenzene 2.45 mol, H ₂ O 1.23 mol, NMP800 in the autoclave.
Add ml and enclose the system in a nitrogen stream and raise the temperature to 225 ° C.
After 2 hours of polymerization, the temperature was raised and further polymerization was carried out at 250 ° C. for 3 hours.

After the completion of the polymerization, the system was cooled and the reaction product was taken out. After repeating the same operation 10 times, the test piece was taken out from the system and the corrosion rate was measured.
No. 8 shows.

As is clear from the table, the equipment material of the present invention did not corrode even under extremely harsh conditions using anhydrous Na ₂ S, and showed remarkable corrosion resistance and durability.

Example 3 No. 1 in Table 1 50 equipped with a high-purity chromium inner cylinder shown in 1
Make an autoclave with a volume of 0 ml and use the following procedure to
Polymerization of PS was performed.

Na ₂ S.2.9H ₂ O was added to the autoclave.
0.6 mol of NMP (150 ml) was added, the mixture was stirred under a nitrogen stream, heated to 215 ° C., and 23.0 ml of a distillate mainly composed of water was distilled off. Then, the system was cooled to 150 ° C., and 0.6 mol of p-dichlorobenzene was added to 50 ml of NMP.
It is added together with, the system is sealed under a nitrogen stream, and the temperature is raised to 25
Polymerization was carried out at 0 ° C. for 3 hours.

After the completion of the polymerization, the system was cooled, the obtained reaction product was put into water to precipitate a polymer, and solid-liquid separation was carried out by filtration. Then, the solid content was washed with about 5 l of warm water and filtered. By returning, the by-product NaCl was removed, and the obtained wet cake was heated and dried under reduced pressure at 100 ° C. overnight to isolate PPS.

The obtained PPS had a yield of 61.6 g and a yield of 95%, a weight average molecular weight (hereinafter abbreviated as Mw) measured by GPC of 33,000, a heavy metal content (measured by an atomic absorption method) of Cr, All of Ni, Fe, and Ti were below the detection limit. (Here, “below the detection limit” means that the content of heavy metals is less than 0.5 ppm.) Regarding the amount of oligomers, the weight loss when soxhlet extraction was performed for 8 hours using methylene chloride as a solvent. It was determined by calculating the rate. The results are shown in Table 4.

As is clear from the table, the PPS obtained by using the material for the device of the present invention is not contaminated by heavy metals which are naturally generated in the autoclave, and the amount of the oligomer is reduced. I know if there is.

Further, using a Koka type flow tester (manufactured by Shimadzu Corporation), using a die at 330 ° C., a diameter of 0.5 mm and a length of 2 mm, the melt viscosity after preheating for 30 minutes (hereinafter,
η ₃₀ ) and the melt viscosity after preheating for 5 minutes (hereinafter, η ₅
Is abbreviated), and the thermal stability is evaluated by taking the ratio (η ₃₀ / η ₅ ). Η ₃₀ / η ₅ =
As a result, PPS having an excellent thermal stability of 1.05 was obtained.

Further, the obtained PPS was heated at 320 ° C. for 30 minutes.
Melt press for 2 seconds to create a sheet with a thickness of 0.3 mm,
When the whiteness was measured using a color meter (manufactured by Suga Test Instruments Co., Ltd.), a sheet having a whiteness of 83 and an extremely high whiteness was obtained. (See Table 4) Examples 4 to 5 Except for using the 500 ml capacity autoclave equipped with the high purity chromium inner cylinder shown in 2 and 3,
Polymerization of PPS was carried out in the same manner as in Example 3. The yield, Mw, heavy metal content, thermal stability, oligomer amount and whiteness of the obtained PPS are summarized in Table 4.

Example 6 Using the same apparatus as in Example 3, PPS was polymerized by the following procedure.

To the autoclave, 0.6 mol of anhydrous Na ₂ S single crystal (purity 99.42%), 0.6 mol of p-dichlorobenzene, 0.3 mol of H ₂ O and 200 ml of NMP were put, and nitrogen was added. The system was sealed in an air stream, the temperature was raised, and polymerization was carried out at 225 ° C for 2 hours and 250 ° C for 3 hours.

After the completion of the polymerization, the system was cooled, the obtained reaction product was put into water to precipitate a polymer, and solid-liquid separation was carried out by filtration. Then, the solid content was washed with about 5 l of warm water and filtered. By returning, the by-product NaCl was removed, and the obtained wet cake was heated and dried under reduced pressure at 100 ° C. overnight to isolate PPS.

The yield, Mw, heavy metal content, thermal stability, oligomer content and whiteness of the obtained PPS are summarized in Table 4.
Shown in.

Example 7 PPSK was polymerized in the following procedure using the same apparatus as in Example 3.

Na ₂ S.2.8H ₂ O was added to the autoclave.
0.166 mol, 4,4'-dichlorobenzophenone (0.168 mol) and NMP (200 ml) were added, the system was sealed under a nitrogen stream, the temperature was raised, and polymerization was carried out at 260 ° C for 1.5 hours.

After the completion of the polymerization, the system was cooled, the obtained reaction product was poured into water to precipitate a polymer, and solid-liquid separation was performed by filtration. Then, the solid content was washed with about 5 liters of warm water and filtered. By returning, the by-product NaCl was removed, and PPSK was isolated by heating and drying the wet cake obtained at 100 ° C. for one day under reduced pressure.

The yield, Mw, heavy metal content and thermal stability of the obtained PPSK are summarized in Table 4.

Example 8 Using the same apparatus as in Example 3, PPSS was polymerized in the following procedure.

Na ₂ S.2.8H ₂ O was added to the autoclave.
0.200 mol, 4,4′-dichlorodiphenyl sulfone 0.202 mol, H ₂ O 2.0 mol, lithium acetate 0.100 mol, NMP 200 ml were charged, the system was sealed under a nitrogen stream and the temperature was raised to 200 Polymerization was carried out at ℃ for 5 hours.

After completion of the polymerization, the system was cooled, the obtained reaction product was put into water to precipitate a polymer, and solid-liquid separation was carried out by filtration. Then, the solid content was washed with about 5 liters of warm water and filtration was repeated. By returning, the by-produced NaCl was removed, and the resulting wet cake was heated and dried at 100 ° C. under reduced pressure for one day to isolate PPSS.

The yield, Mw, heavy metal content, thermal stability and whiteness of the obtained PPSS are summarized in Table 4.

Comparative Examples 2 to 5 Nos. Nos. 4 to 5 and No. 2 in Table 2. Polymerization of PPS was carried out in the same manner as in Example 3 except that an autoclave of 500 ml capacity equipped with an inner cylinder made of the materials shown in 6 to 7 was used.

The yield, Mw, heavy metal content, thermal stability, oligomer content and whiteness of the obtained PPS are summarized in Table 4.
Shown in.

As is apparent from the above, PPS obtained by using the apparatus made of the material other than the present invention is contaminated by the heavy metal which is naturally generated in the autoclave, and has a high thermal stability and whiteness. I could only get inferior.

[0080]

[Table 4]

[Procedure amendment]

[Submission date] August 5, 1991

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0051

[Correction method] Change

[Correction content]

[0051]

[Table 1]

Claims (3)

[Claims] 1. A polyarylene sulfide that is substantially free of heavy metals. 2. When a polyarylene sulfide is produced by reacting an alkali metal sulfide with a dihaloaromatic compound in a polar aprotic solvent, at least the liquid contact portion has a relative density of 95% or more and a purity of 99. A method for producing polyarylene sulfide, which is characterized in that it is produced using an apparatus composed of high purity chromium of 7% or more. 3. An apparatus for producing a polyarylene sulfide by reacting an alkali metal sulfide with a dihaloaromatic compound in a polar aprotic solvent, the apparatus having a relative density of 95% or more and a purity of 99.7. % Poly-arylene sulfide manufacturing equipment, which is characterized by being made of high-purity chromium of at least%.