JPH0618876B2 - Method for producing polyarylene sulfide - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing polyarylene sulfide, and more specifically, it is white and has a high molecular weight,
Polyarylene sulfide, which can be suitably used as a material for various molded products, films, fibers, mechanical parts, electric parts, electronic parts, etc., can be produced by a simple process while recovering polar solvents with little deterioration. The present invention relates to a method for producing a polyarylene sulfide that can be used.

[Prior Art and Its Problems] Polyarylene sulfide such as polyphenylene sulfide is a thermoplastic resin having a part of thermosetting property, and has excellent chemical resistance, good mechanical properties in a wide temperature range,
It has excellent properties as an engineering plastic, such as heat resistance and rigidity.

And, it is known that polyarylene sulfide such as polyphenylene sulfide is usually obtained by polycondensation reaction of a dihalogenated aromatic compound and an alkali metal sulfide in a polar solvent, for example, production of polyphenylene sulfide. Is usually carried out by polycondensation reaction of p-dichlorobenzene and sodium sulfide in a polar solvent (see Japanese Patent Publication No. 52-12240).

Here, when an alkali metal sulfide conventionally obtained in the form of a hydrate is used, two steps, a dehydration step and a polycondensation step of a hydrous alkali metal sulfide, are required in the production of polyarylene sulfide. .

This dehydration step has usually been performed by a method of azeotropically distilling water in the presence of a polar solvent, but at this time, for example, a stainless steel reactor is corroded and impurities eluted from the inner wall of the reactor are polar. When mixed in the solvent, there was a problem that the purity and whiteness of the obtained polyarylene sulfide was lowered, or the polar solvent to be recovered was deteriorated.

On the other hand, a method of carrying out the reaction in the presence of a substantially anhydrous metal sulfide, metal carbonate, dihalogen aromatic compound and a trace amount of water (see JP-A-59-22926) is also known.

However, in this method, a large amount of oligomers and the like are by-produced, the high molecular weight is insufficient, and the yield is poor.
Since it is necessary to react for a long time in order to attain a high molecular weight, there is a problem that it is industrially disadvantageous.

[Object of the Invention] An object of the present invention is to solve the above problems, suppress corrosion of a reactor as much as possible, and recover a solvent with little deterioration while efficiently and stably producing a white, high molecular weight polyarylene sulfide. Is to provide.

[Means for Achieving the Object] As a result of extensive studies conducted by the present inventor to achieve the object, a substantially anhydrous metal sulfide was used as a raw material, and the metal sulfide and a trace amount of hydrogen sulfide were used. It was found that a white and high molecular weight polyarylene sulfide can be efficiently and stably produced by pretreatment in a polar solvent in the presence of water and then polycondensation by adding a dihalogenated aromatic compound. The invention was reached.

That is, the outline of the present invention is a method for producing a polyarylene sulfide by bringing a dihalogen aromatic compound and a metal sulfide into contact with each other in a polar solvent, and the method is selected from alkali metal sulfides and alkaline earth metal sulfides. After pretreating a metal sulfide having a water / sulfide molar ratio of 1.2 or less with at least one species at a temperature of 45 to 230 ° C. with hydrogen sulfide and a trace amount of water, a pretreated metal sulfide and A method for producing a polyarylene sulfide, which comprises reacting with a dihalogenated aromatic compound.

The polar solvent used in the method of the present invention includes, for example, amide compounds, lactam compounds, urea compounds, cyclic organophosphorus compounds and the like. Specifically, 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-isobutyl caprolactam, N-normal propyl caprolactam, N-normal butyl caprolactam,
N-cyclohexylcaprolactam, N-methyl-2-
Pyrrolidone, N-ethyl-2-pyrrolidone, N-isopropyl-2-pyrrolidone, N-isobutyl-2-pyrrolidone, N-normalpropyl-2-pyrrolidone, N-normalbutyl-2-pyrrolidone, N-cyclohexyl-
2-pyrrolidone, N-methyl-3-methyl-2-pyrrolidone, N-cyclohexyl-2-pyrrolidone, N-ethyl-3-methyl-2-pyrrolidone, N-methyl-3,4,5
-Trimethyl-2-pyrrolidone, N-methyl-2-piperidone, N-isopropyl-2-piperidone, N-methyl-2-piperidone, N-ethyl-2-piperidone, N
-Isopropyl-2-piperidone, N-methyl-6-methyl-2-piperidone, N-methyl-3-ethyl-2-
Piperidone, tetramethylurea, N, N'-dimethylethyleneurea, N, N'-dimethylpropyleneurea, 1-
Methyl-1-oxosulfolane, 1-ethyl-1-oxosulfolane, 1-phenyl-1-oxosulfolane,
Examples thereof include 1-methyl-1-oxophosphorane, 1-normalpropyl-1-oxonephosphorane, 1-phenyl-1-oxophosphorane and the like.

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

Among the above-mentioned various solvents, N-alkyllactam and N-alkylpyrrolidone are preferable, and N-methylpyrrolidone is particularly preferable.

The dihalogenated aromatic compound [hereinafter sometimes referred to as the component (A). ], For example, m-dihalobenzene,
Dihalogenbenzenes such as p-dihalobenzene; 2,3-
Dihalotoluene, 2,5-dihalotoluene, 2,6-dihalotoluene, 3,4-dihalotoluene, 2,5-dihaloxylene,
1-ethyl-2,5-dihalobenzene, 1,2,4,5-tetramethyl-3,6-dihalobenzene, 1-normalhexyl-
Dihalogen- or cycloalkyl-substituted benzenes such as 2,5-dihalobenzene and 1-cyclohexyl-2,5-dihalobenzene; 1-phenyl-2,5-dihalobenzene, 1-benzyl-2,5-dihalobenzene, 1-p-
Toluyl-2,5-dihalobenzene and other dihalogen aryl-substituted benzenes; 4,4'-dihalobiphenyl and other dihalogen biphenyls; 1,4-dihalonaphthalene, 1,6-dihalonaphthalene, 2,6-dihalogen Examples thereof include dihalogen naphthalene such as halonaphthalene.

The two halogen elements in these dihalogenated aromatic compounds are respectively fluorine, chlorine, bromine or iodine, which may be the same or different from each other.

Among the above-mentioned component (A), dihalobenzenes are preferable, and p-dichlorobenzene is particularly preferable.

The metal sulfide [hereinafter sometimes referred to as the component (B). ] Is one or more selected from alkali metal sulfides and alkaline earth metal sulfides, and has a water / sulfide molar ratio of 1.2 or less (including 0).

Examples of the alkali metal sulfide used as the component (B) in the method of the present invention include lithium sulfide, sodium sulfide, potassium sulfide, rubidium sulfide, and cesium sulfide. These may be used alone or in combination of two or more. Among these, lithium sulfide and sodium sulfide are preferable, and sodium sulfide is particularly preferable.

Examples of the alkaline earth metal sulfide used as the component (B) in the method of the present invention include calcium sulfide, strontium sulfide, barium sulfide, beryllium sulfide, magnesium sulfide and the like. These are 1
They may be used alone or in combination of two or more. Among these, calcium sulfide and magnesium sulfide are preferable.

In the method of the present invention, any one of the alkali metal sulfides and alkaline earth metal sulfides may be selected and used, or two or more thereof may be used in combination.

The hydrogen sulfide [hereinafter sometimes referred to as the component (C). ]
May be obtained by any method, but it is preferable to use, for example, a pure product obtained by reacting iron (II) sulfide with a dilute acid.

The water [hereinafter sometimes referred to as the component (D). ] Is preferably sufficiently purified, for example, distilled water,
Ion exchanged water or the like can be preferably used.

In the method of the present invention, a known catalyst used for producing a polyarylene sulfide is optionally used in the polycondensation reaction of the dihalogenated aromatic compound as the component (A) and the metal sulfide as the component (B). Although it can be used, particularly preferred are lithium acetate, sodium acetate and lithium chloride.

Next, the use ratio of each component in the method of the present invention will be described.

The dihalogenated aromatic compound as the component (A) is usually used in an amount of 0.75 to 1 mol with respect to 1 mol of the metal sulfide as the component (B).
It is used in an amount of 2.0 mol, preferably 0.90 to 1.2 mol. Since the reaction between the dihalogenated aromatic compound (A) and the metal sulfide (B) is an equimolar reaction, it is usually within the above range.

The component (C), hydrogen sulfide, is used usually in the range of 0.001 to 0.30 mol, preferably 0.01 to 0.10 mol, per 1 mol of the component (B) metal sulfide. This ratio is 0.001
If the amount is less than the molar amount, there is no effect of adding hydrogen sulfide, the molar balance is lost, and it may be difficult to increase the molecular weight.
On the other hand, if it exceeds 0.30 mol, it may cause corrosion of the equipment, and the solvent may be deteriorated, and gas countermeasures are required when handling the product.

The water of the component (D) is the metal sulfide 1 of the component (B).
It is used in the range of 1.3 to 4.5 mol, preferably 1.4 to 3.2 mol, based on mol. If this ratio is less than 1.3 mol, the polymerization rate may be slow and the increase in the molecular weight may not proceed. On the other hand, if it exceeds 4.5 mol, side reactions may occur concurrently, the product may not have a high molecular weight, and the pressure may increase during polycondensation.

Furthermore, when a catalyst is used, the usage ratio of the catalyst depends on the kind of the catalyst, but is usually 0.03 to 2.0 mol, preferably 0.1 to 1.1 mol per 1 mol of the metal sulfide of the component (B).
6 mol. If this ratio is less than 0.03, the reaction rate becomes remarkably slow, and it may not be possible to achieve a high molecular weight polymer. On the other hand, even if it is used in excess of 2.0 mol, the effect corresponding to that is not exhibited, and rather the catalyst may remain in the produced polymer.

The amount of the polar solvent used in the method of the present invention is not particularly limited as long as it is an amount sufficient for the reaction to proceed uniformly.
Usually, it is in the range of 0.1 to 10 times the weight of the total weight of the components (A), (B), (C) and (D) and the catalyst. If the amount used is less than 0.1 times the weight, the reaction may not proceed sufficiently. On the other hand, if it exceeds 10 times the weight, the volumetric efficiency will deteriorate and the productivity will decrease.

In the method of the present invention, the metal sulfide of the component (B) is usually added in the presence of hydrogen sulfide of the component (C) and water of the component (D) at a temperature of 45 to 230 ° C., preferably 80 ° C. ~ 200
Pretreatment is performed under the condition of ° C. By this pretreatment, the charging ratio of the dihalogenated aromatic compound as the component (A) and the metal sulfide as the component (B) is maintained. If the pretreatment temperature is lower than 45 ° C, the molecular weight of the polymer produced is not sufficient. On the other hand, if the temperature exceeds 230 ° C, the metal sulfide that is the component (B) may decompose and the reaction may not proceed sufficiently. The time required for this pretreatment is usually 5 minutes to 4 hours, preferably 10 minutes to 3 hours. If this treatment time is less than 5 minutes, the reaction will not proceed sufficiently.
On the other hand, even if the pretreatment is performed for more than 4 hours, the corrosion of the apparatus becomes severe and the effect equivalent to the treatment time is not exhibited.

Further, in the method of the present invention, in the polycondensation reaction of the dihalogenated aromatic compound as the component (A) and the metal sulfide as the component (B), an active hydrogen-containing halogenated aromatic compound is optionally added, Branching agents such as polyhalogenated aromatic compounds and halogenated aromatic nitro compounds, molecular weight regulators such as monohalogenated aromatic compounds and active hydrogen-containing compounds, liquidity regulators such as alkali hydroxides, polymerization additives such as metal salts. Alternatively, an inert organic solvent may be appropriately selected and added to the reaction system. These added components are preferably used in the reaction in a substantially anhydrous state.

The active hydrogen-containing halogen aromatic compound is, for example, a halogen aromatic compound having a functional group having active hydrogen such as an amino group, a thiol group, and a hydroxyl group, and as such, for example, 2,6 -Dichloroaniline, 2,5-dichloroaniline, 2,4-dichloroaniline, dihaloanilines such as 2,3-dichloroaniline; 2,3,4-trichloroaniline, 2,3,5, -trichloroaniline, 2, Trihaloanilines such as 4,6-trichloroaniline and 3,4,5-trichloroaniline; 2,2'-diamino-4,4'-dichlorodiphenyl ether, 2,4'-diamino-2 ', 4-dichlorodiphenyl ether Examples of such dihaloaminodiphenyl ethers and mixtures thereof include compounds in which an amino group is replaced with a thiol group or a hydroxyl group. Further, an active hydrogen-containing halogen aromatic compound in which a hydrogen atom bonded to a carbon atom forming an aromatic ring in these active hydrogen-containing halogen aromatic compounds is substituted with another inert group such as a hydrocarbon group such as an alkyl group. Group compounds can also be used. Among these various active hydrogen-containing halogen aromatic compounds, the active hydrogen-containing dihalogen aromatic compounds are preferable, and dichloroaniline is particularly preferable.

Examples of the polyhalogenated aromatic compound include 1,2,
4-trichlorobenzene, 1,3,5-trichlorobenzene,
1,4,6-trichloronaphthalene and the like can be mentioned.

Examples of the halogen aromatic nitro compound include 2,
Mono- or dihalonitrobenzenes such as 4-dinitrochlorobenzene and 2,5-dichloronitrobenzene; Dihalonitrodiphenyl ethers such as 2-nitro-4,4'-dichlorodiphenyl ether; 3,3'-dinitro-4,4 ' −
Dihalonitrodiphenyl sulfones such as dichlorodiphenyl sulfone; 2,5-dichloro-3-nitropyridine,
Examples thereof include mono- or dihalonitropyridines such as 2-chloro-3,5-dinitropyridine, and various dihalonitronaphthalenes.

By using these active hydrogen-containing halogen aromatic compounds, polyhalogen aromatic compounds, halogen aromatic nitro compounds, etc., the degree of branching of the polymer produced can be increased, the molecular weight can be further increased, or residual salt-containing compounds can be obtained. It is possible to further improve various properties of the polymer produced by the method of the present invention, such as reducing the amount.

Examples of the monohalogenated aromatic compound include chlorobenzene, bromobenzene, α-bromotoluene, α-chlorotoluene, o-chlorotoluene, m-chlorotoluene,
P-chlorotoluene, α-bromotoluene, o-bromotoluene, m-bromotoluene, p-bromotoluene and the like can be mentioned.

Examples of the active hydrogen-containing compound include thiophenol, phenol and aniline.

Further, as the branching agent or the molecular weight modifier, in addition to the above compounds, for example, a compound having three or more reactive halogen atoms such as cyanuric chloride can be used.

In the method of the present invention, these branching agents or molecular weight modifiers may be used alone or in combination of two or more.

Examples of the polymerization additive include metal hydrides such as sodium borohydride and calcium hydride, alkali formate, hydrazine and sulfur.

Examples of the inert solvent include benzene, toluene, xylene, biphenyl, terphenylnaphthalene,
Hydrocarbons such as anthracene, diphenyl ether,
p-diphenoxybenzene, polyethylene glycol,
Examples thereof include ethers such as dioxane, and among these, high boiling point inert organic solvents are preferable.

The polyarylene sulfide is produced by the method of the present invention, for example, as follows.

That is, first, a required amount of the metal sulfide [(B) component], hydrogen sulfide [(C) component] and water [(D) component] were added to the polar solvent, respectively, and the temperature was 45 to 230 ° C. Pretreatment for 5 minutes to 4 hours, and then a dihalogenated aromatic compound [component (A)], a required amount of a polymerization catalyst used as desired, and various additive components used if necessary. Then, the polycondensation reaction is carried out by heating to a temperature in the range of 180 to 330 ° C, preferably 220 to 300 ° C. If the reaction temperature is less than 180 ° C., the reaction rate will be slow, which is not practical. On the other hand, if the temperature exceeds 330 ° C., side reactions or deterioration of the produced polymer occur, which causes coloring or gelation. The reaction time cannot be unconditionally determined because it varies depending on the type and amount ratio of each component used, the type and amount of catalyst, the reaction time, etc., but usually within 20 hours,
It is preferably about 0.1 to 8 hours. In the method of the present invention, this polycondensation reaction can be carried out in an atmosphere of an inert gas such as nitrogen, argon or carbon dioxide.

The reaction pressure is not particularly limited, but it is usually the self-pressure of a polycondensation reaction system such as a solvent to 50 kg / cm ² (absolute pressure). The polycondensation reaction may be a one-step reaction carried out at a constant temperature, a multi-step reaction in which the temperature is raised stepwise, or a reaction mode in which the temperature is gradually raised continuously.

Then, the isolated polymer is usually washed with water, methanol, acetone or the like to remove the alkali metal halide, the alkali metal sulfide, the polymerization catalyst and the like adhering to the polymer. Alternatively, the polymer produced from the reaction-terminated liquid can be obtained by distilling the solvent off and collecting the polymer without isolating it, and washing the residue as described above. The recovered solvent can be reused.

The polyarylene sulfide thus obtained is
It can be processed into various molding materials and used. However, various desalting treatments can be carried out as necessary to further reduce the salt content of sodium chloride and the like in the electric and electronic fields. Can be suitably used.

When the polyarylene sulfide obtained by the method of the present invention is molded into various products, for example, other polymers, pigments, graphite, metal powder, glass powder, quartz powder,
It is also possible to mix it with a filler such as glass fiber, a stabilizer, a release agent and the like for molding.

[Advantages of the Invention] According to the present invention, (1) a specific metal sulfide is pretreated and used under specific conditions, so that corrosion of the apparatus is not caused, and (2) high whiteness and high molecular weight. The polyarylene sulfide of (1) can be stably produced in a high yield, and (3) moreover, a dehydration step is unnecessary, and a polar solvent with little deterioration can be recovered and reused, and so on. An industrially advantageous method for producing a polyarylene sulfide having an advantage can be provided.

EXAMPLES Next, examples and comparative examples of the present invention will be shown to more specifically describe the present invention.

(Example 1) 48.03 g of sodium sulfide 0.5 hydrate equivalent product (purity Na ₂ S conversion 88.2%) in 1-autoclave made of SUS 316L
(0.543 mol), water 12 ml (0.667 mol), and N-methylpyrrolidone 206 ml are added, hydrogen sulfide 240 ml (about 0.01 mol) is added, and the temperature is 130 ° C under a nitrogen atmosphere.
Heated for minutes.

Then, the temperature was lowered to 85 ° C., the lid was opened, and 79.8 g (0.543 mol) of p-dichlorobenzene and 100 ml of N-methylpyrrolidone were added.
After adding, the mixture was sealed and reacted at a temperature of 260 ° C. for 3 hours.

Then the reaction mixture is poured into water 1, filtered off and
The washing was performed twice in the order of water washing and acetone washing.

The polymer obtained is white with a yield of 82% (48.1 g).
Met. The solution viscosity η measured using a 1-chloronaphthalene solvent having a concentration of 0.4 g / dl under the condition of a temperature of 206 ° C.
inh was 0.08. Further, the recovered N-methylpyrrolidone was light brown, and the used autoclave did not generate rust.

(Example 2) In Example 1, lithium acetate 3 was used during the polycondensation reaction.
Example 1 was repeated except that 5.8 g (0.543 mol) was used.

The obtained polymer is white and its yield is 91% (53.6
g), the solution viscosity ηinh was 0.18. The recovered N-methylpyrrolidone was light brown, and the autoclave used did not have rust.

(Example 3) In Example 1, the lithium chloride 2 was added during the polycondensation reaction.
Example 1 was repeated except that 3.0 g (0.543 mol) was used.

The polymer obtained is white and its yield is 92% (54.0%).
g), the solution viscosity ηinh was 0.24. The recovered N-methylpyrrolidone was light brown, and the autoclave used did not have rust.

Comparative Example 1 A polymer was obtained in the same manner as in Example 1 except that water was not used in Example 1.

The yield of the obtained polymer was 10.2% (5.97 g), and the solution viscosity ηinh was 0.009. After completion of the reaction, a part of the reaction solution was sampled and the residual p-dichlorobenzene was quantified by gas chromatography (column: PEG20M chromosolve, 2 m, temperature 210 ° C). %Met.

As is clear from the above, the yield of the polymer obtained in this Comparative Example was lower than that in any of Examples 1 to 3, and the molecular weight was small and the purity was poor.

(Comparative Example 2) A polymer was obtained in the same manner as in Example 1 except that water and hydrogen sulfide were not used in Example 1.

The yield of the obtained polymer was 9.8% (5.75 g), and the solution viscosity ηinh was 0.0045. After completion of the reaction, a part of the reaction solution was sampled and the residual p-dichlorobenzene was quantified by gas chromatography (column: PEG20M chromosolve, 2 m, temperature 210 ° C). %Met.

As is clear from the above, the yield of the polymer obtained in this Comparative Example was lower than that in any of Examples 1 to 3, and the molecular weight was small and the purity was poor.

Comparative Example 3 A polymer was obtained in the same manner as in Example 1 except that the initial mixture was stirred at room temperature for 15 minutes and then p-dichlorobenzene was added to carry out the reaction.

The yield of the obtained polymer was 54% (31.7 g), the solution viscosity η
inh was 0.04. After completion of the reaction, a part of the reaction solution was sampled and the residual p-dichlorobenzene was quantified by gas chromatography (column: PEG20M chromosolve, 2 m, temperature 210 ° C). %Met.

As is clear from the above, the yield of the polymer obtained in this Comparative Example was lower than that in any of Examples 1 to 3, and the molecular weight was small and the purity was poor.

Claims (1)

[Claims] 1. A method for producing a polyarylene sulfide by contacting a dihalogenated aromatic compound and a metal sulfide in a polar solvent, which comprises at least one selected from alkali metal sulfides and alkaline earth metal sulfides. There is water /
Pretreatment of a metal sulfide having a sulfide molar ratio of 1.2 or less with hydrogen sulfide and a trace amount of water at a temperature of 45 to 230 ° C., and then reacting the pretreated metal sulfide with a dihalogenated aromatic compound A method for producing a polyarylene sulfide, which comprises: