JPH0617475B2 - Polyarylene sulfide and method for producing same - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to polyarylene sulfide and a method for producing the same, and more specifically to polyarylene sulfide which has a high molecular weight, high crystallinity and excellent moldability, and is suitable as a raw material for, for example, various films, fibers and other molded products, and a method for producing the polyarylene sulfide.

[Background Art] Polyarylene sulfides such as polyphenylene sulfide are thermoplastic resins that are partially thermosetting, and have excellent properties as engineering plastics, such as excellent chemical resistance, good mechanical properties over a wide temperature range, and heat-resistant rigidity.

It is known that polyarylene sulfides such as polyphenylene sulfide are usually obtained by polymerizing a dihalogen aromatic compound with an alkali metal sulfide in a polar solvent. For example, polyphenylene sulfide is usually produced by polymerizing p-dichlorobenzene with sodium sulfide in a polar solvent (Japanese Patent Publication No. 12240/1977, etc.).

Here, since alkali metal sulfides are usually obtained in the form of hydrates, the production of polyarylene sulfide requires two steps: a step of dehydrating the hydrated alkali metal sulfide and a step of polycondensation.

This dehydration step is usually carried out by azeotropic distillation of water in the presence of a polar solvent, but the hydrogen sulfide produced as a by-product during this process corrodes, for example, stainless steel reactors,
Impurities are eluted from the inner wall of the reactor and mixed into the polar solvent, which reduces the purity and whiteness of the resulting polyarylene sulfide and makes it impossible to recover the polar solvent with little deterioration.

To solve this problem, a reaction apparatus made of titanium has been proposed (see Japanese Patent Application Laid-Open No. 61-23627), but titanium is expensive and therefore disadvantageous from an industrial standpoint.

On the other hand, a method using lithium halide as a catalyst (U.S. Pat. No. 4,038,263) has been known as a method for producing high-molecular-weight polyphenylene sulfide, but this method has not yielded high-molecular-weight polyphenylene sulfide having excellent melting properties that enable the resulting polymer to be used to produce films, fibers, and non-reinforced molded articles.

Furthermore, a method of making a compound having three or more halogens present in a reaction system has been proposed as a method for producing a high molecular weight branched polyphenylene sulfide (see Japanese Patent Publication No. 54-8719 and Japanese Patent Laid-Open No. 59-197430). However, the polyphenylene sulfide obtained by this method has problems in that it is prone to gelation and suffers from a significant decrease in crystallinity.

[Objective of the Invention] This invention was made based on the above circumstances.

That is, an object of the present invention is to provide a polyarylene sulfide which has a high molecular weight, high crystallinity and excellent moldability.

Another object of the present invention is to provide a method for producing a polyarylene sulfide that is white, highly pure, has a high molecular weight, and is highly crystalline, with a low content of impurity salts, without corroding the equipment during the dehydration step or polycondensation step.

A further object of the present invention is to provide a method for producing polyarylene sulfide in a stable state without causing gelation of the resulting polymer.

[Disclosure of the Invention] The gist of the present invention to achieve the above object is to provide a compound represented by the formula [1]; A structural unit [I] represented by the formula [2]; (wherein, in formula [2], Ar represents an aromatic residue, and X ^o
represents -N- or -O-, R represents a hydrogen atom, an alkyl group or an aryl group, and when ^Xo represents -N-, t is 1, and when ^Xo represents -O-, t is 0. The polyarylene sulfide is characterized in that it comprises a structural unit [II] represented by the following formula:

In order to produce a polyarylene sulfide that has the above-mentioned characteristics and that is white, highly pure, and has a small content of impurity salts without corroding the equipment in the dehydration step or the condensation polymerization step, it is preferable to employ a process in which a hydrous alkali metal sulfide is first dehydrated in a polar solvent in the presence of a lithium compound, and then the dihalogen aromatic compound is brought into contact with the alkali metal sulfide in the presence of a halogen aromatic compound and/or a halogen aromatic nitro compound containing active hydrogen.

This polyarylene sulfide contains the structural unit [I]
and the structural unit [II] are thought to be bonded, for example, as shown in the following formula:

Here, the structural unit [I] usually has 1 to 500 (preferably 50 to 200) repeating units, and the structural unit [II] usually has 1 to 10 (preferably 1 to 5) repeating units.

The structure of the above-mentioned [II] itself depends on the structure of the dihalogen aromatic compound and/or halogen aromatic nitro compound containing active hydrogen, which will be described later, but it is preferably represented by the following formula [2a]:

(However, in formula [2a], Ar has the same meaning as above.) Anyway, in this polyarylene sulfide,
The structural unit [I] represented by the formula [1] is usually 90 to 99.99% by weight, preferably 98 to 99.95% by weight, and the structural unit [II] represented by the formula [2] is usually 10 to 0.01% by weight.
Preferably, it is 2 to 0.05% by weight.

If the structural unit [II] exceeds 10% by weight, the resulting polymer may gel or become discolored during production or molding, whereas if the structural unit [II] is less than 0.01% by weight, the molecular weight of the resulting polymer may decrease, resulting in deterioration of mechanical properties such as rigidity.

The weight average molecular weight is a value measured by a light scattering method using a 1-chloronaphthalene solution at a temperature of 235° C., and is usually 2,000 to 500,000, preferably 10,000 to 20
When the weight average molecular weight is less than 2,000,
Mechanical properties such as rigidity may decrease.
If it exceeds 0,000, moldability may deteriorate.

The inherent viscosity ηinh of the polyarylene sulfide of this invention (relating to a 1-chloronaphthalene solution heated to 206°C and having a concentration of 0.4 g/d) is usually 0.
03 to 0.60.

The polyarylene sulfide of the present invention can be produced, for example, by contacting a dihalogen aromatic compound with an alkali metal sulfide in a polar solvent in the presence of a lithium compound and an active hydrogen-containing halogen aromatic compound.

The method for producing the polyarylene sulfide of the present invention will be explained below.

The polar solvents include amide compounds, lactam compounds, urea compounds, and cyclic organic phosphorus compounds.

Among these, specific examples of suitable solvents include:
For example, N,N-dimethylformamide, N,N-dimethylacetamide, N,N-diethylacetamide, N,N-dipropylacetamide, N,N-dimethylbenzoic acid amide,
Caprolactam, N-methylcaprolactam, N-ethylcaprolactam, N-isopropylcaprolactam,
N-isobutylcaprolactam, N-propylcaprolactam, N-butylcaprolactam, N-cyclohexylcaprolactam, N-methyl-2-pyrrolidone, N-
Ethyl-2-pyrrolidone, N-isopropyl-2-pyrrolidone, N-isobutyl-2-pyrrolidone, N-propyl-2-pyrrolidone, N-butyl-2-pyrrolidone, N
-cyclohexyl-2-pyrrolidone, N-methyl-3-
Methyl-2-pyrrolidone, N-cyclohexyl-2-pyrrolidone, N-methyl-3-methyl-2-pyrrolidone,
N-methyl-3,4,5-trimethyl-2-pyrrolidone, N
-methyl-2-piperidone, N-ethyl-2-piperidone, N-isopropyl-2-piperidone, N-isobutyl-2-piperidone, N-methyl-6-methyl-2-piperidone, N-methyl-3-ethyl-2-piperidone,
N-methyl-2-oxo-hexamethyleneimine, N-
ethyl-2-oxo-hexamethyleneimine, tetramethylurea, 1,3-dimethylethyleneurea, 1,3-dimethylpropyleneurea, 1-methyl-1-oxosulfolane,
1-ethyl-1-oxosulfolane, 1-phenyl-1
1-oxosulfolane, 1-methyl-1-oxophosphorane, 1-propyl-1-oxophosphorane, 1-phenyl-1-oxophosphorane, and the like.

The above-mentioned various compounds can be used as a solvent either singly or as a mixture of two or more.

Furthermore, among the various polar solvents mentioned above, lactam compounds are preferred, N-alkyl lactams are more preferred, N-alkyl pyrrolidones are further preferred, and N-methyl pyrrolidone is particularly preferred.

Examples of the dihalogen aromatic compound include m-
Dichlorobenzene, p-dichlorobenzene, p-dibromobenzene, m-dibromobenzene, 1-chloro-4-
Dihalogenated benzenes such as bromobenzene; 2,5-dichlorotoluene, 2,5-dichloroxylene, 1-ethyl-2,5-dichlorobenzene, 1-ethyl-2,5-dibromobenzene, 1-ethyl-2-bromo-5-chlorobenzene, 1,2,4,5-tetramethyl-3,6-dichlorobenzene,
1-cyclohexyl-2,5-dichlorobenzene, 1-phenyl-2,5-dichlorobenzene, 1-benzyl-2,5-
Dichlorobenzene, 1-phenyl-2,5-dibromobenzene, 1-p-toluyl-2,5-dichlorobenzene, 1
and substituted dihalogenated benzenes such as 1-hexyl-2,5-dichlorobenzene, 1-hexyl-4-toluyl-2,5-dibromobenzene, etc. Among these, dihalogenated benzenes are preferred, with p-dichlorobenzene being particularly preferred.

Examples of the alkali metal sulfide include lithium sulfide, sodium sulfide, potassium sulfide, rubidium sulfide, cesium sulfide, and mixtures thereof. Hydrous alkali metal sulfides, which are usually hydrates or aqueous mixtures, can also be used.

The hydrated alkali metal sulfide may be, for example, Na ₂ S
Examples of the alkali metal phosphate salt include Na ₂ S·9H ₂ O, Na 2 S·5H ₂ O, Na ₂ S·3H ₂ O, and mixtures thereof.

The alkali metal sulfide is preferably lithium sulfide or sodium sulfide.

Examples of the active hydrogen-containing halogenated aromatic compound include compounds represented by the following formulas [3] and [4].

[In the formula [3], X represents a halogen atom selected from fluorine, chlorine, bromine, and iodine, and Y represents —NHR
(wherein R represents a hydrogen atom, an alkyl group, or an aryl group), or —OH, k represents an integer of 2 to 5, and l represents an integer of 1 to 4 (wherein k+
l is always an integer between 3 and 6. [In the formula [4], X and Y have the same meanings as X and Y in the formula [3], and Z is -O-, -S
-, -SO-, _-SO2- , -CO-, -( ^{CR1R2 )} _P-
(wherein ^R1 and ^R2 represent hydrogen or an alkyl group) or a single bond, and r, t, m, and n represent integers of 0 or more that simultaneously satisfy 2≦(r+t)≦{10−(n+m)}, 1≦(n+m)≦{10−(n+m)}, (r+n)≦5, and (t+m)≦5.) Examples of active hydrogen-containing halogen aromatic compounds represented by the formula [3] include 2,6-dichloroaniline, 2,5-
Active hydrogen-containing dihalogenbenzene compounds such as dichloroaniline, 2,4-dichloroaniline, and 2,3-dichloroaniline; active hydrogen-containing trihalogenbenzene compounds such as 2,3,4-trichloroaniline, 2,3,5-trichloroaniline, 2,3,6-trichloroaniline, 2,4,5-trichloroaniline, 2,4,6-trichloroaniline, and 3,4,5-trichloroaniline; 2,3,4,5-tetrachloroaniline, 2,3,
Examples include active hydrogen-containing polyhalogenbenzene compounds such as 5,6-tetrachloroaniline.

The active hydrogen-containing dihalogen aromatic compound represented by the formula [4] is, for example, 2,2'-diamino-4,4'-
Dichlorodiphenyl ether, 2,4'-diamino-2',
4-Dichlorodiphenyl ether; 2,2'-diamino-4,
4'-dichlorodiphenyl thioether, 2,4'-diamino-2',4-dichlorodiphenyl thioether; 2,2'
-diamino-4,4'-dichlorodiphenyl sulfoxide, 2,4'-diamino-2',4-dichlorodiphenyl sulfoxide; 2,2'-diamino-4,4'-dichlorodiphenyl sulfone, 2,4'-diamino-2',4-dichlorodiphenyl sulfone; 2,2'-diamino-4,4'-dichlorodiphenylmethane, 2,4'-diamino-2',4-dichlorodiphenylmethane;2,5-dichloro-4'-aminodiphenyl ether, 2,5-dibromo-4'-aminodiphenyl ethers; 2,5-dichloro-4'-aminodiphenyl thioether, 2,5-dibromo-4'-aminodiphenyl thioether; 2,5-dichloro-4'-aminodiphenyl sulfoxide, 2,5-dibromo-4'-aminodiphenyl sulfoxide; 2,5-dichloro-4'-aminodiphenyl sulfone, 2,5-dibromo-4'-aminodiphenyl sulfone; 2,5-dichloro-4'-aminodiphenylmethane, 2,5-dibromo-4'-aminodiphenylmethane, and the like.

In producing the arylene sulfide of the present invention, in addition to the active hydrogen-containing dihalogen aromatic compounds represented by the above formulas [3] to [4], compounds in which an active hydrogen-containing group, for example, an amino group is substituted on the naphthalene nucleus and a halogen atom is also substituted can be used.

Among the various active hydrogen-containing halogenated aromatic compounds exemplified above, those represented by the formula [5]: [In the formula [5], X represents a halogen atom, and Y represents NH
R ⁰ (wherein R ⁰ represents an alkyl group or an aryl group) or NH ₂ , and u represents an integer of 1 to 4.] are preferred, and dichloroaniline is particularly preferred.

In the reaction, the mixing ratio of the above components is usually as follows:

That is, the molar ratio of component (a)/component (b) between the dihalogen aromatic compound (a) and the alkali metal sulfide (b) is 0.75 to 2.0, preferably 0.90 to 1.2. The reaction between the dihalogen aromatic compound and the alkali metal sulfide is an equimolar reaction, so the molar ratio is usually within the above range.

The active hydrogen-containing halogenated aromatic compound (c) is
The content is 0.005 to 2.0 mol % of the component, preferably 0.01
If the amount of the component (C) is less than 0.005 mol %, the molecular weight of the polyarylene sulfide may decrease, while if it is more than 2.0 mol %, gelation may occur in some cases.

The molar ratio of the polar solvent (d) to the alkali metal sulfide (b) is 1 to 15, preferably 2.
If this molar ratio is less than 1, the reaction may become non-uniform, and if the molar ratio is greater than 15, productivity may decrease.

In addition, in producing this polyarylene sulfide,
It is preferable to have an alkali metal hydroxide (e) and a known metal carboxylate or aromatic sulfonate as a catalyst coexist in the reaction system, and a reducing agent may also be coexistent.

Examples of the alkali metal hydroxide include lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide, etc. Among these, lithium hydroxide, sodium hydroxide, and potassium hydroxide are preferred.

Examples of the metal carboxylate include lithium acetate, lithium propionate, lithium 2-methylpropionate, lithium butyrate, lithium 3-methylbutyrate, lithium valerate, lithium hexanoate, lithium heptanoate, lithium benzoate, sodium benzoate, and zinc acetate. Among these, lithium carboxylate is preferred, and lithium acetate is particularly preferred. Hydrates of such metal carboxylates may also be used.

Examples of aromatic carboxylates include sodium p-toluenesulfonate.

The reaction may be carried out in a reducing atmosphere, or a reducing agent may be added. Examples of the reducing agent include hydrazine, hydrides, and alkali formates. Preferred are hydrides, particularly borohydrides [lithium borohydride, sodium borohydride (NaBH ₄ ), potassium borohydride] and calcium hydride (CaH ₂ ).

The molar ratio of component (e)/component (b) is 2.0 or less, preferably 0.01 to 1.5. If this molar ratio is greater than 2.0, the melt flow of the resulting polymer may not be reduced.

The alkali metal hydroxide is used to make the reaction system alkaline, and there is no particular limitation on the amount added.

These components may be contacted simultaneously or separately during the reaction, and there is no particular limitation on the contact of the components.

The reaction is usually carried out at a temperature of 180 to 320°C, preferably 220 to 300°C.
The temperature range is

The reaction time is usually within 20 hours, particularly within 0.1 to 8 hours.

After the reaction is complete, the polyarylene sulfide can be separated from the reaction solution directly by standard methods, such as filtration or centrifugation, or can be separated from the reaction solution after adding, for example, water and/or diluted acid.

The filtration step is generally followed by washing with water to remove any inorganic components, such as alkali metal sulfides and alkali metal hydroxides, which may adhere to the polymer. Washing or extraction with other washing solutions can also be performed in addition to or after this washing step. The polymer can be recovered by distilling off the solvent from the reaction vessel, followed by washing as described above.

The polyarylene sulfide of the present invention can be produced as described above. However, a more preferred method for producing a high-molecular-weight, highly crystalline polyarylene sulfide that is white and highly pure with a low content of impurity salts without corroding the equipment in the dehydration step or condensation polymerization step is a process in which a hydrous alkali metal sulfide is first dehydrated in a polar solvent in the presence of a lithium compound, and then a dihalogen aromatic compound is contacted with the alkali metal sulfide in the presence of a halogen aromatic compound and/or a halogen aromatic nitro compound containing active hydrogen.

In this more preferred manufacturing process, a polar solvent
The hydrated alkali metal sulfide, the active hydrogen-containing halogenated aromatic compound, the dihalogenated aromatic compound, and the alkali metal sulfide are as described above.

Examples of the lithium compounds include lithium fluoride, lithium chloride, lithium bromide, lithium iodide, lithium carbonate, lithium hydrogen carbonate, lithium sulfate,
Lithium hydrogen sulfate, lithium sulfite, lithium phosphate,
lithium mineral acid salts such as lithium hydrogen phosphate, lithium dihydrogen phosphate, lithium nitrate, and lithium nitrite; lithium oxyacid salts such as lithium chlorate, lithium chromate, and lithium molybdate; lithium carboxylates such as lithium formate, lithium acetate, lithium oxalate, lithium malonate, lithium propionate, lithium butyrate, lithium isobutyrate, lithium maleate, lithium fumarate, lithium 2-methylpropionate, lithium 3-methylbutyrate, lithium valerate, lithium hexanoate, lithium heptanoate, lithium octanoate, lithium tartrate, lithium stearate, lithium benzoate, and lithium phthalate; lithium sulfonates such as lithium benzenesulfonate and lithium p-toluenesulfonate; lithium alkoxides such as lithium methoxide, lithium ethoxide, lithium isopropoxide, lithium n-propoxide, lithium butoxide, and lithium phenoxide;
Examples of the lithium compounds include lithium acetate or organolithium compounds such as lithium acetylacetonate, lithium sulfide, lithium oxide, lithium hydroxide, and the like.

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

Among these, lithium halides such as lithium chloride, lithium carboxylates such as lithium acetate, and lithium carbonate are particularly preferred, with lithium chloride being particularly preferred.

The halogenated aromatic nitro compound may be a compound represented by the following formula [6]:
Compounds represented by [7] and [8] can be used.

(wherein ^X1 is a halogen atom, a is 1 or 2, b is an integer of 1 to 5, and a+b is greater than 3 and less than 6.) [wherein ^Y2 is a single bond, —O—, —S—, (wherein w is an integer of 1 or more), and o and p are each an integer of 0 to 2, and satisfy the relationship 0+p=1 or 2;
c and d are integers of 0 to 5, and 1<c+d≦10
−(o+p) relationship is satisfied.] (wherein e is an integer of 1 or 2, f is an integer of 1 to 4, and e+f is greater than 3 and less than 5.) Examples of compounds represented by the general formula [6] include 2,4-dinitrochlorobenzene and 2,5-dichloronitrobenzene.

The compounds represented by the general formula [7] include, for example, 2-nitro-4,4'-dichlorodiphenyl ether, 3,
3'-dinitro-4,4'-dichlorodiphenyl sulfone and the like.

Examples of the compound represented by the general formula [8] include 2,5-dichloro-3-nitropyridine and 2-chloro-3,5-dinitropyridine.

These halogenated aromatic nitro compounds may be used alone or in combination of two or more.

In this invention, in addition to the compounds represented by the above formulas [6] to [8], alkyl derivatives of the compounds represented by the above general formulas [6] to [8] can also be used as the halogenoaromatic nitro compound.

Among the various halogenated aromatic nitro compounds, dihalogenated aromatic nitro compounds are particularly preferred, such as 2,5-
Dichloronitrobenzene.

In a more preferred production method, when the hydrated alkali metal sulfide is previously dehydrated in the polar solvent in the presence of the lithium compound, the compounding ratio of the lithium compound to the hydrated alkali metal sulfide is usually desirably as follows:

That is, the molar ratio of (lithium compound)/(hydrated alkali metal sulfide) is 0.03 to 2.0, preferably 0.1 to 1.6. If this molar ratio is less than 0.03, a sufficient corrosion prevention effect may not be obtained, while if it exceeds 2.0, the polymerization following dehydration may not proceed easily, resulting in a decrease in the yield of polyarylene sulfide.

In the polymerization reaction, the blending ratio of each component is usually preferably as follows:

That is, the molar ratio of (dihalogen aromatic compound)/(alkali metal sulfide) and the molar ratio of (active hydrogen-containing halogen aromatic compound)/(alkali metal sulfide) are as described above.

The molar ratio of (dihalogen aromatic nitro compound)/(alkali metal sulfide) is usually 0.05 to 2.0 mol%, preferably 0.1 to 1.0 mol%. If the amount of component (E) added is less than 0.05 mol%, the melt flow ratio of the resulting polymer may increase, while if it is more than 2.0 mol%, the polymer may gel.

The molar ratio of (lithium compound)/(alkali metal sulfide) is usually 0.001 to 2.0, preferably 0.01 to 1.5. If this molar ratio is less than 0.001, the molecular weight of the polyarylene sulfide produced may be low, or the content of salts such as table salt remaining in the polymer, i.e., contaminant salts, may not be sufficiently reduced. On the other hand, if it is more than 2.0, the salt used as the catalyst may remain in the produced polymer at a high concentration, or the molecular weight may not be sufficiently large.

The more preferable reaction time, reaction temperature and post-reaction treatment in this production method are also as described above.

The content of salts such as common salt remaining in the polyarylene sulfide recovered in this manner is significantly lower than that in polyarylene sulfides produced by conventionally known methods, and therefore the polyarylene sulfide has high moisture-resistant electrical insulation properties. The polyarylene sulfide can then be molded and processed without any particular desalination treatment and can be suitably used in the electrical and electronic fields. However, if necessary, various desalination treatments can be carried out in addition to or after the washing step to further reduce the concentration of salts such as common salt in the resin before use.

When the polyarylene sulfide of the present invention is molded into various products, it can be mixed with other polymers, pigments and fillers such as graphite, metal powder, glass powder, quartz powder or glass fiber, or additives commonly used for polyarylene sulfides, such as conventional stabilizers or mold release agents.

The polyarylene sulfide of the present invention has a small melt flow rate and a high molecular weight, and also has high crystallinity, excellent moldability and rigidity.

Therefore, according to the present invention, it is possible to provide polyarylene sulfide, which is an excellent engineering plastic that can be made into, for example, various films, fibers, and other molded products and can be suitably used for mechanical parts, electronic parts, etc.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an infrared absorption spectrum of the polyarylene sulfide obtained in Example 1 of the production method of the present invention;
FIG. 2 is an infrared absorption spectrum of the polyarylene sulfide obtained by a conventional method, FIG. 3 is a chart showing the results of gas chromatographic analysis of the polyarylene sulfide obtained in Example 3, and FIG. 4 is a chart showing the results of gas chromatographic analysis of the polyarylene sulfide obtained in Comparative Example 2.

BEST MODE FOR CARRYING OUT THE INVENTION Next, examples of the present invention will be shown to further explain the polyarylene sulfide of the present invention.

(Example 1) p-Dichlorobenzene 81.5 g (0.56 mol), lithium sulfide
25.0 g (0.54 mol), 2,5-dichloroaniline 0.164 g (0.00
1 mol) and 0.914 g (0.024 mol) of sodium borohydride were added, and 30 g of N-methyl-2-pyrrolidone was added as a solvent.
6 ml (2.93 mol) of the mixture was charged into two autoclaves, and after passing nitrogen through them at room temperature for 10 minutes, the mixture was heated with stirring.
After heating to 0°C, the autoclave was sealed and heated to 265°C.
The temperature was raised to 190°C and the reaction was carried out for 3 hours. After the reaction was completed, the mixture was cooled to 190°C with stirring and then allowed to cool to room temperature. The reaction mixture was poured into water (1), filtered, washed with water for 30 minutes, and washed with methanol for 30 minutes, in that order.

The inherent viscosity of the obtained polyphenylene sulfide is η inh
(206°C, 1-chloronaphthalene 0.4g/d solution) is 0.
The melt flow value was 0.034 m/sec, measured at a temperature of 300°C and a load of 50 kg/ ^cm² using a nozzle with a diameter of 1 mm and a length of 10 mm.

The composition of the resulting polyphenylene sulfide was such that the content of the structural unit [I] was 99.82% by weight, the content of the structural unit [II][II] was 0.18% by weight, and the weight-average molecular weight was 75,100.

The identification data is shown below.

Infrared absorption spectrum (KBr tablet method): 1320 cm ^-1 (C-N) The infrared absorption spectrum of this polyphenylene sulfide is shown in FIG.

Nitrogen analysis (Kjeldahl method): 0.011% The infrared absorption spectrum data of the C-N bond was based on the infrared absorption spectrum data of the C-N bond of diphenylamine (no triphenylamine is produced as a by-product) obtained by reacting chlorobenzene with aniline.

(Example 2) 2. In an autoclave, 130.4 g of sodium sulfide nonahydrate was added.
(0.54 mol), 35.8 g (0.54 mol) of lithium acetate, 40.1 g (0.54 mol) of lithium carbonate, and 370 ml of N-methyl-2-pyrrolidone were added, and 88 ml of water was removed by azeotropic distillation.
0.161 g (0.001 mol) of 2,5-dichloroaniline and N-
150 ml of methyl-2-pyrrolidone was added, and the reaction was carried out in a nitrogen atmosphere at 265° C. for 3 hours. The reaction product was poured into 0.1 N hydrochloric acid, filtered, washed with water for 30 minutes, and then washed with methanol for 30 minutes.

The inherent viscosity of the obtained polyphenylene sulfide is η inh
(206°C, 1-chloronaphthalene 0.4g/d solution) is 0.1
9 and the melt flow value was 0.40 m/sec.

The composition of the obtained polyphenylene sulfide was such that the content of the structural unit [I] was 99.84% by weight, the content of the structural unit [II] was 0.16% by weight, and the weight average molecular weight was
The figure was 40,100.

The identification data is shown below.

Infrared absorption spectrum (KBr tablet method): 1320 cm ^-1 (C-N) Nitrogen analysis (Kjeldahl method): 0.010% (Example 3) 130.4 g (0.54 mol) of sodium sulfide nonahydrate and 23.0 g (0.
54 mol) and 356 ml of N-methylpyrrolidone,
A mixture of N-methylpyrrolidone and water was obtained by azeotropic distillation.
The hydrogen sulfide generated at this time was collected in a trap containing a sodium hydroxide solution, and when quantified using the iodine method, it was found to be 1.
It was 5 mol %.

Then, 81.5 g (0.56 mol) of p-dichlorobenzene, 2,5
- 0.80 g (0.005 mol) of dichloroaniline and 150 ml of N-methylpyrrolidone were added and heated at 270°C under a nitrogen atmosphere.
The reaction was carried out for 3 hours. After cooling to room temperature, the autoclave was opened. The N-methylpyrrolidone phase was pale yellow, and granular polymer and white powder were observed at the bottom. The autoclave maintained its luster, and no corrosion was observed.

Ion-exchanged water was poured into the reaction mixture, and after filtering,
The resulting granular polyphenylene sulfide (52.9%) was washed with ion-exchanged water and then with methanol.
The product (g) was white and had an inherent viscosity index ηinh (206°C, 1-chloronaphthalene 0.4 g/d solution) of 0.31.

After the reaction was completed, the reaction mixture was analyzed by a gas chromatograph (column: PE
Gas chromatographic analysis of N-methylpyrrolidone was carried out using a G-20M Chromosorg column (column temperature 200°C, detector temperature 230°C, injector temperature 230°C).

The results are shown in FIG.

The composition of the obtained polyphenylene sulfide was such that the content of the structural unit [I] was 99.80% by weight, the content of the structural unit [II] was 0.20% by weight, and the weight average molecular weight was
The figure was 73,200.

Comparative Example 1 In Example 3, sodium sulfide nonahydrate was azeotropically dehydrated without using lithium chloride, and when p-dichlorobenzene and 2,5-dichloroaniline were added, 160 g of N-methylpyrrolidone containing 23.0 g (0.54 mol) of lithium chloride was used.
Polyphenylene sulfide was produced in the same manner as in Example 3 except for adding sodium sulfide m, and N-methylpyrrolidone after the reaction was analyzed by gas chromatography. In this comparative example, the amount of hydrogen sulfide generated during dehydration was 0.52 mol % based on the charged sodium sulfide. When the autoclave was opened before filtering and washing, the N-methylpyrrolidone phase was dark brown, and black rust was observed on the liquid-contacting parts of the autoclave.

Granular polyphenylene sulfide (47.5 g) obtained after filtering and washing was brown in color and had an inherent viscosity index ηinh (206°C, 1-chloronaphthalene 0.4 g/d solution) of
The value was 0.27.

The results of analysis by gas chromatography are shown in FIG.

As is clear from FIG. 4, the N-methylpyrrolidone after the reaction contained a large amount of impurities.

The composition of the obtained polyphenylene sulfide was such that the content of the structural unit [I] was 99.83% by weight, the content of the structural unit [II] was 0.17% by weight, and the weight average molecular weight was
The figure was 72,900.

(Example 4) In the same manner as in Example 3, 0.80 g of 2,5-dichloroaniline was used.
The same procedure as in Example 3 was repeated except that 0.103 g (0.0006 mol) of 2,5-dichloro-1-nitrobenzene was used instead of 0.005 mol of toluene.
Polyarylene sulfide was produced in the same manner as above.

The resulting granular polyphenylene sulfide (53.8 g) was white and had an inherent viscosity index ηinh (206° C., 1-chloronaphthalene 0.4 g/d solution) of 0.45.

In the infrared absorption spectrum of the produced polyphenylene sulfide, an absorption at 1,320 cm ^-1 due to C-N is observed.
No _NO2 -based absorption was observed.

The composition of the obtained polyphenylene sulfide was such that the content of the structural unit [I] was 99.77% by weight, the content of the structural unit [II] was 0.23% by weight, and the weight average molecular weight was
The figure was 148,200.

(Comparative Example 2) In the same manner as in Example 1, 0.80 g of 2,5-dichloroaniline was used.
(0.005 mol) was replaced with 0.893 g (0.005
The reaction was carried out in the same manner as in Example 1 except that 1,000 moles of methylcellulose was used. The polymer produced gelled in the autoclave and became insoluble.

The polyarylene sulfide of the present invention has a small melt flow rate, a high molecular weight, high crystallinity, and excellent moldability and rigidity. Therefore, the polyarylene sulfide can be made into various films, fibers, and other molded products, and can be suitably used for mechanical parts, electronic parts, etc.

Claims (21)

[Claims] [Claim 1] Formula [1]; A structural unit [I] represented by the formula [2]; (wherein, in formula [2], Ar represents an aromatic residue, and X ^o
represents -N-, -O-, R represents a hydrogen atom, an alkyl group or an aryl group, and when ^Xo represents -N-, t is 1, and when ^Xo represents -O-, t is 0. A polyarylene sulfide comprising a structural unit [I] of the formula: Claim 2: In the formula [2], ^Xo is -N- and R
The polyarylene sulfide according to claim 1, wherein is a hydrogen atom. 3. The polyarylene sulfide according to claim 1, wherein the structural unit [I] is 98 to 99.95% by weight and the structural unit [II] is 2 to 0.05% by weight. 4. The polyarylene sulfide according to claim 1, wherein the weight average molecular weight of the polyarylene sulfide is 10,000 to 200,000. 5. The polyarylene sulfide according to claim 1, wherein the inherent viscosity of said polyarylene sulfide is 0.03 to 0.60. [Claim 6] A method for producing polyarylene sulfide as described in claim 1, characterized in that a hydrous alkali metal sulfide is first dehydrated in the presence of a lithium compound in a polar solvent, and then a dihalogen aromatic compound is contacted with the alkali metal sulfide in the presence of a halogen aromatic compound and/or a halogen aromatic nitro compound containing active hydrogen. 7. The method for producing polyarylene sulfide according to claim 6, wherein the polar solvent is a lactam compound. 8. The method for producing polyarylene sulfide according to claim 6, wherein the lactam compound is N-alkylpyrrolidone. 9. The method for producing polyarylene sulfide according to claim 6, wherein the lactam compound is N-methylpyrrolidone. 10. The method for producing polyarylene sulfide according to claim 6, wherein the lithium compound is at least one selected from the group consisting of lithium halide, lithium carboxylate, and lithium carbonate. 11. The method for producing polyarylene sulfide according to claim 6, wherein the lithium compound is a lithium halide. 12. The method for producing polyarylene sulfide according to claim 6, wherein the lithium compound is lithium chloride. 13. The method for producing polyarylene sulfide according to claim 6, wherein said hydrated alkali metal sulfide is at least one of lithium sulfide hydrate and sodium sulfide hydrate. [Claim 14] A method for producing polyarylene sulfide described in claim 6, wherein the halogenated aromatic compound containing active hydrogen is at least one compound represented by the following formulas [3] to [4]. [In the formula [3], X represents a halogen atom such as fluorine, chlorine, or bromine, and Y represents -NHR (wherein R represents a hydrogen atom,
represents an alkyl group or an aryl group; —OH; k represents an integer of 2 to 5; and l represents an integer of 1 to 4 (provided that k+l is always an integer of 3 to 6). [In the formula [4], X and Y have the same meanings as X and Y in the formula [3], and Z is -O-, -S
-, -SO-, _-SO2- , -CO-, -( ^{CR1R2 )} _P-
(wherein ^R1 and ^R2 represent hydrogen or an alkyl group) or a single bond, and r, t, m, and n are each 2≦(r+t)≦{10−(n+m)}, 1≦(n+m)
≦{10−(n+m)}, (r+n)≦5, and (t+
m) represents an integer of 0 or more that simultaneously satisfies ≦5. 15. The halogenated aromatic compound containing active hydrogen, wherein the halogenated aromatic compound is represented by the formula [5]: [In the formula [5], X represents a halogen atom, and Y represents NH
R (wherein R represents an alkyl group or an aryl group) or _NH2 , and u represents an integer of 1 to 4. 16. The method for producing polyarylene sulfide according to claim 6, wherein the halogenated aromatic compound containing active hydrogen is dichloroaniline. 17. The halogenated aromatic nitro compound of claim 17, wherein the halogenated aromatic nitro compound is a compound of the formula:
[6], [7] and [8] (wherein X is a halogen atom, a is 1 or 2, and b is 1
is an integer between 1 and 5, and a+b is greater than 3 and less than 6. [wherein ^Y2 is a single bond, —O—, —S—, (wherein w is an integer of 1 or more), and o and p are each an integer of 0 to 2, and satisfy the relationship 0+p=1 or 2;
c and d are integers of 0 to 5, and 1<c+d≦10
−(o+p) relationship is satisfied.] (wherein e is an integer of 1 or 2, f is an integer of 1 to 4, and e+f is greater than 3 and less than 5). 18. The method for producing polyarylene sulfide according to claim 6, wherein the halogenated aromatic nitro compound is a dihalogenated aromatic nitro compound. 19. The halogenated aromatic nitro compound of claim 2,
A method for producing the polyarylene sulfide according to claim 6, wherein the polyarylene sulfide is 5-dichloronitrobenzene. 20. The method for producing polyarylene sulfide according to claim 6, wherein the dihalogen aromatic compound is a dihalogen-substituted benzene. 21. The method for producing polyarylene sulfide according to claim 6, wherein the dihalogen aromatic compound is p-dichlorobenzene.