JPH0645693B2 - Method for producing polyarylene sulfide - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing polyarylene sulfide,
More specifically, it is a method for producing a high molecular weight polyarylene sulfide that is excellent in moldability and has no coloration, which can be suitably used as a material for various molded products, films, fibers, mechanical parts, electric and electronic parts, etc. Regarding

[Prior Art and Problems to be Solved by the Invention] Polyarylene sulfides such as high molecular weight polyphenylene sulfides have excellent chemical resistance, good mechanical properties in a wide temperature range, heat resistance, and the like as engineering plastics. It has excellent properties.

And, polyarylene sulfide such as polyphenylene sulfide is generally known to be obtained by polycondensation reaction of a dihalogenated aromatic compound and an alkali metal sulfide in a polar solvent, for example, polyphenylene sulfide is usually , P-dichlorobenzene and sodium sulfide are subjected to polycondensation reaction in a polar solvent (see Japanese Patent Publication No. 52-12240).

However, the polyarylene sulfide such as the polyphenylene sulfide obtained in this manner is not necessarily one having a high molecular weight, and means for increasing the molecular weight is important.

As a means for increasing the molecular weight, conventionally, a method of subjecting a hydrous alkali metal sulfide to a dehydration treatment prior to the polymerization reaction and adjusting the proportion of water in the reaction solution to be subjected to the polymerization is known, but only this method is known. Then, the high molecular weight is insufficient,
Therefore, a branching agent is added to the reaction solution to carry out the polymerization reaction,
Further, a method for increasing the molecular weight has been used (see US Pat. No. 4,038,261). However, in the conventional method in which the branching agent is simply added to increase the molecular weight, a sufficiently high molecular weight is used. Although polyarylene sulfide such as polyphenylene sulfide can be obtained relatively easily, due to the increase in the molecular weight,
The melt flowability of the polymer is reduced. Therefore, it is possible to raise the molding temperature, but if the molding temperature is raised, the polymer will decompose, so it is necessary to increase the injection pressure during injection molding, and as a result, burrs are likely to occur in the molded product,
It is a major drawback in polyarylene sulfide.

Further, a method of increasing the molecular weight by heating the polymer in the presence of oxygen has been proposed, but in this method, it is difficult to control branching / crosslinking, and the coloring of the polymer is prone to There is a problem that a treatment process is required.

Therefore, there is no deterioration of physical properties such as strength and coloring of the polymer, melt flowability at normal molding temperature is good, moldability in injection molding is excellent, and a sufficiently high molecular weight without burr is highly practical. It has been desired to develop a method capable of easily and stably producing polyarylene sulfide.

The present invention has been made in view of the above circumstances.

The object of the present invention is to eliminate the above-mentioned problems, to have an excellent melt flowability while having a sufficiently high molecular weight, to facilitate the molding process, and to prevent burrs from being generated during the molding process, and to achieve excellent molding without coloring. It is to provide a method for producing a polyarylene sulfide that can be processed into a product.

[Means for Solving the Problems] As a result of intensive studies to solve the above problems, the present inventors have found that the above objects can be achieved by controlling the molar ratio of the reaction raw materials. This invention was reached.

That is, the constitution of the present invention, in a polar solvent, (A) at least one metal sulfide selected from the group consisting of alkali metal sulfides and alkali metal hydrosulfides and (B) dihalogenated aromatic compound and (C ) In the case of contacting and reacting an aromatic compound having three or more functional groups, the aforementioned
The molar ratio of the component (B) to the component (A) is [(B) /
(A)] in the range of 1.035 to 1.300, and the ratio of the (C) component to the (B) component used is in the range of 0.003 to 0.05 in the molar ratio [(C) / (B)]. The method for producing a polyarylene sulfide is characterized by

Examples of the polar solvent used in the method of the present invention include organic amide compounds, lactam compounds, urea compounds, cyclic organic phosphorus compounds and the like. In particular,
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-normalpropylcaprolactam, N-normalptylcaprolactam, N-cyclohexylcaprolactam, N-methyl-
2-pyrrolidone, N-ethyl-2-pyrrolidone, N-isopropyl-2-pyrrolidone, N-isobutyl-2-pyrrolidone, N-normalpropyl-2-pyrrolidone, N
-Normal butyl-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 '
-Dimethylethylene urea, N, N'-dimethylpropylene urea, 1-methyl-1-oxosulfolane, 1-ethyl-1-oxosulfolane, 1-phenyl-1-oxosulfolane, 1-methyl-1-oxophosphorane , 1-
Normal propyl-1-oxophosphorane, and 1-
Phenyl-1-oxophosphorane and the like can be mentioned.

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

Among the various polar solvents, aprotic organic amides or lactams can be preferably used, and among these, N-alkyllactam and N-alkylpyrrolidone are preferable, and N- is particularly preferable.
It is methylpyrrolidone.

In the present invention, the component (A) may be referred to as an alkali metal sulfide [hereinafter, referred to as a component (A ₁ ). ] And an alkali metal hydrosulfide [hereinafter, sometimes referred to as a component (A ₂ ). ] At least one selected from the group consisting of

Here, when the alkali metal hydrosulfide (A ₂ ) is used, it is usually preferable to use a base together.

As the base, an alkali metal hydrosulfide is converted into an alkali metal sulfide, or a hydrogen hologenide which can be generated by condensation of an alkali metal hydrosulfide and a dihalogenated aromatic compound (B) is efficiently neutralized or As long as it is an acid acceptor that can be accepted and does not hinder the object of the present invention, various types of inorganic bases, organic bases and the like can be used. In the usual case, an alkali metal hydroxide or the like can be preferably used.

Specific examples of the alkali metal hydroxide include lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide and cesium hydroxide.

Among these, lithium hydroxide and sodium hydroxide are preferable, and sodium hydroxide is particularly preferable.

These bases such as alkali metal hydroxides may be used alone or in combination of two or more.

The amount of the base such as alkali metal hydroxide to be used, if desired, is 1 equivalent of the alkali metal hydrosulfide used (1
It is necessary to have at least about 1 equivalent per mol).

Specific examples of the alkali metal sulfide include, for example,
Examples thereof include lithium sulfide, sodium sulfide, potassium sulfide, rubidium sulfide, and cesium sulfide.

Among these, lithium sulfide and sodium sulfide are preferable, and sodium sulfide is particularly preferable.

These alkali metal sulfides may be used alone or in combination of two or more.

Examples of the alkali metal hydrosulfide include lithium hydrosulfide (L
iHS), sodium hydrosulfide (NaHS), potassium hydrosulfide (KH
S), rubidium hydrosulfide (RbHS), hydrofluidized calcium (CaHS)
And cesium hydrosulfide (CsHS).

Among these, sodium hydrosulfide and lithium hydrosulfide are preferable, and sodium hydrosulfide is particularly preferable.

In the present invention, both the alkali metal sulfide and the alkali metal hydrosulfide can be used as an anhydride, or can be used as a hydrate or an aqueous mixture as a commercial product or for industrial use.

However, when these hydrates or aqueous mixtures contain a large amount of water in the polycondensation system when they are used as they are, a dehydration step can usually be provided prior to the polymerization reaction.

Examples of the dihalogenated aromatic compound (B) include m
-Dihalobenzenes such as dihalobenzene and 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-3,8
Alkyl-substituted dihalobenzenes or cycloalkyl-substituted benzenes such as dihalobenzene, 1-normalhexyl-2,5-dihalobenzene, and 1-cyclohexyl-2,5-dihalobenzene; 1-phenyl-2,
Aryl-substituted dihalobenzenes such as 5-dihalobenzene, 1-benzyl-2,5-dihalobenzene, and 1-p-toluyl-2,5-dihalobenzene; dihalobiphenyls such as 4,4-dihalobiphenyl; Four
-Dihalonaphthalene, 1,6-dihalonaphthalene, and dihalonaphthalene such as 2,6-dihalonaphthalene.

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 (B), dihalobenzenes are preferable, and p-dichlorobenzene is particularly preferable.

In the present invention, the aromatic compound having three or more functional groups, which is used as the component (C), is an aromatic compound and has three reactive functional groups bonded to an aromatic ring. Or more, usually 3 or 4, preferably 3
It is a compound that has an individual.

Examples of the reactive functional group include an active hydrogen-containing group such as an amino group, a hydroxyl group, a mercapto group, a carboxyl group, a sulfonyl group, a sulfino group, a sulfamoyl group, a hydrazino group, and a carbamoyl group, a halogen atom, and a nitro group. And so on. The reactive functional groups bonded to the aromatic ring may be the same or different.

The reactive functional group is preferably an amino group, a halogen atom and a nitro group (claim 2).

Examples of the halogen atom which is a reactive functional group include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. Of these, chlorine atom is particularly preferable.

Examples of the aromatic compound having three or more functional groups include benzenes, biphenyls, diphenyl ethers, diphenyl sulfides, and naphthalenes. Among these, benzenes are particularly preferable.

As the aromatic compound having three or more functional groups, for example, active hydrogen-containing halogen aromatic compound, polyhalogen aromatic compound, halogen aromatic nitro compound and the like can be preferably used.

Examples of the active hydrogen-containing halogen aromatic compound include a halogen aromatic compound having the active hydrogen-containing group such as an amino group, a mercapto group, and a hydroxyl group. Examples of such a compound include 2, Dihaloanilines such as 6-dichloroaniline, 2,5-dichloroaniline, 2,4-dichloroaniline and 2,3-dichloroaniline; 2,3,4-trichloroaniline, 2,3,5-trichloroaniline, 2, 4,6
-Trihaloanilines such as trichloroaniline and 3,4,5-trichloroaniline; 2,2'-diamino-4,
Amino group-containing halogen aromatic compounds such as dihaloaminodiphenyl ethers such as 4'-dichlorodiphenyl ether and 2,4'-diamino-2 ', 4-dichlorodiphenyl ether, and various compounds in which the amino group is a thiol group or Examples thereof include compounds substituted with a hydroxyl group. In addition, amino group-containing haloaromatic compounds in which a hydrogen atom bonded to a carbon atom forming an aromatic ring in these active hydrogen-containing haloaromatic compounds is substituted with another inert group such as a hydrocarbon group such as an alkyl group. Active hydrogen-containing haloaromatic compounds such as group compounds can also be used. Among these various active hydrogen-containing halo aromatic compounds, active hydrogen-containing dihalo aromatic compounds can be preferably used, and among them, amino group-containing dihalo aromatic compounds are preferable, and dichloroaniline is particularly preferable.

As the polyhalogenated aromatic compound, those generally used can be used, among which, for example, 1, 2,
4-trichlorobenzene, 1,3,5-trichlorobenzene, 1,4,6-trichloronaphthalene and the like can be preferably used, and particularly 1,2,4-trichlorobenzene and 1,3,5-trichlorobenzene can be used. Chlorobenzene can be preferably used.

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

In addition, in this invention, the said aromatic compound (C) which has three or more functional groups may be used individually by 1 type, and may use 2 or more types together.

In the present invention, the polar solvent [hereinafter sometimes referred to as the component (D)]. ], At least the metal sulfide (A)
And the dihalogenated aromatic compound (B) and the aromatic compound (C) having three or more functional groups are brought into contact with each other and reacted to synthesize a polyarylene sulfide such as polyphenylene sulfide.

However, when carrying out this reaction,
The molar ratio [(B) / (A)] with the component (B) is in the range of 1.035 to 1.300, preferably 1.04 to 1.15, and the component (B) is
The molar ratio [(C) / (B)] with the component (C) is within the range of 0.003 to 0.05, preferably 0.004 to 0.02.

When these molar ratios are out of the above ranges,
Even if a sufficiently high molecular weight polyarylene sulfide cannot be obtained, or even if the molecular weight is sufficiently high, the melt flowability of the obtained polyarylene sulfide is insufficient and the moldability, especially the moldability by injection molding, Becomes insufficient,
This molding pressure becomes high and burrs are easily generated during injection molding (However, under the condition that [(B) / (A)] is 1.2 or more and [(C) / (B)] is 0.5 or more. , But it is not practical because the yield becomes low as the polymer becomes brittle, but the polymer tends to be colored in some cases, and the object of the present invention is to be achieved. I can't.

In the present invention, the polymerization reaction can be carried out in the presence of appropriate water, as is usually done.

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, relative to the total weight of the components (A), (B), (C) and other optional components (excluding solvent),
It is in the range of 0.1 to 10 times the weight. 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.

Further, in the method of the present invention, during the polymerization reaction, if desired, a catalyst or a polymerization aid, a molecular weight modifier such as a monohalogenated aromatic compound or an active hydrogen-containing compound, and a liquid property adjustment such as an alkali metal hydroxide. An agent, a reducing agent and the like can be appropriately selected and added to the reaction system for use.

The catalyst or the polymerization aid [hereinafter sometimes referred to as the component (E). ], Various known ones can be used, and examples thereof include alkali metal halides, alkali metal carboxylates, alkali metal carbonates, and alkali metal borates.

As the alkali metal halide, alkali metal fluorides, alkali metal chlorides, alkali metal bromides and alkali metal iodides can be used. Specifically, for example, lithium fluoride, sodium fluoride, potassium fluoride can be used. , Lithium chloride, sodium chloride, potassium chloride, rubidium chloride, cesium chloride, lithium bromide, sodium bromide, cesium bromide, lithium iodide,
Examples thereof include sodium iodide, potassium iodide, and cesium iodide.

Of these, lithium chloride is particularly preferable.

When the dehydration step is adopted, this alkali metal halide is usually used by adding it to the polar solvent (D) prior to the dehydration.

As the alkali metal carboxylate, for example, lithium acetate, sodium acetate, potassium acetate, cesium acetate, lithium benzoate, sodium benzoate, potassium benzoate, lithium formate, sodium formate, lithium propionate, sodium propionate, shu. Lithium acid, sodium oxalate, lithium butyrate, sodium butyrate, lithium isobutyrate, sodium isobutyrate, lithium valerate, sodium valerate, lithium hexanoate, sodium hexanoate, lithium octanoate, sodium octanoate, lithium fumarate, fumaric acid Sodium acid,
Examples thereof include lithium malonate, sodium malonate, lithium tartrate, sodium tartrate, lithium stearate, sodium stearate, lithium phthalate, and sodium phthalate.

Among these, especially lithium acetate, sodium acetate,
And lithium benzoate are preferred.

Examples of the alkali metal carbonates include lithium carbonate, sodium carbonate, potassium carbonate, rubidium carbonate, and cesium carbonate.

Among these, lithium carbonate and sodium carbonate are preferable, and lithium carbonate is particularly preferable.

Examples of the alkali metal borate include lithium borate, sodium borate, potassium borate, and cesium borate.

Among these, lithium borate and sodium borate are preferable, and lithium borate is particularly preferable.

The catalyst or polymerization aid which is the component (E) is the component (A).
It is usually 0.08 to 1 mol of metal sulfide as a component.
It is used in an amount of 2.0 mol, preferably 0.5 to 1.8 mol.
If this ratio is less than 0.03 mol, a sufficiently high molecular weight polyarylene sulfide may not be obtained, while if it exceeds 2.0 mol, the metal sulfide (A) is easily decomposed and the polymerization reaction May not proceed smoothly.

Examples of the monohalogenated aromatic compound include chlorobenzene, bromobenzene, α-bromobenzene, α-chlorotoluene, o-chlorotoluene, m-chlorotoluene,
Examples thereof include p-chlorotoluene, α-bromotoluene, o-bumutoluene, m-bromotoluene, and p-bromotoluene.

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 reducing agent include hydrazine, metal hydride, alkali formate, and sulfur. Among these, metal hydrides are preferable, and sodium borohydride and calcium hydride are particularly preferable.

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

That is, in order to synthesize a polyarylene sulfide by the method of the present invention, the component (A), the component (B), the component (C) and the component (D), or these and various components optionally used as described above. Is mixed at a predetermined ratio, and if necessary, the reaction liquid obtained by adjusting the water ratio within the above-mentioned predetermined range is usually 180 to 330 ° C., preferably 220 to 30.
The polymerization reaction is performed by heating to a temperature in the range of 0 ° C. If the reaction temperature is less than 180 ° C, the reaction rate will be slow, which is not practical. On the other hand, when the temperature exceeds 330 ° C, side reactions and deterioration of the produced polymer occur, which causes coloring and gelation. The reaction time cannot be unconditionally determined because it varies depending on the type and amount ratio of each component used, the type of catalyst, etc., but it is usually within 20 hours, preferably about 0.1 to 8 hours.

In the method of the present invention, this polycondensation reaction can be carried out under an atmosphere of an inert gas such as nitrogen, argon and 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.

After the completion of the polymerization reaction, the synthesized polyarylene sulfide is directly separated from the reaction vessel by a standard method such as filtration or centrifugation, or, for example, water and / or a diluted acid or the like. After the flocculation liquid is added, the reaction liquid can be separated and isolated.

Then, the isolated polymer is usually washed with water, methanol, acetone or the like to give an alkali metal halide, an alkali metal sulfide, a polymerization aid and a side reaction product attached to the polymer. Etc. are removed. Also,
It is also possible to obtain the polymer by isolating and recovering the solvent without isolating the polymer produced from the reaction-terminated liquid 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,
A filler such as glass fiber, a stabilizer, a release agent, and the like can be blended and molded.

[Effects of the Invention] According to the present invention, while having a sufficiently high molecular weight that it can be used as an engineering resin, it has excellent melt fluidity and is easy to mold, and there is little burr during molding. Thus, it is possible to stably produce a polyarylene sulfide that can be molded into an excellent molded product without coloring.

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

(Examples 1 to 8 and Comparative Examples 1 to 8) Sodium sulfide pentahydrate 1,3
After adding 70 g, 345 g of lithium chloride (however, lithium chloride was not added in Example 2 and Comparative Example 3), and 4,160 ml of N-methylpyrrolidone (NMP), the temperature was raised to 200 ° C. under a nitrogen atmosphere. 1,8 with water and NMP mixture
Distilled 30 ml. After cooling the residue to 100 ° C, NM
Paradichlorobenzene (PDCB), dichloronitrobenzene (DCNB) or trichlorobenzene dissolved in 1,500 ml of P
(TCB) was added to the residual sodium sulphide in a defined molar ratio. Then, the mixture was reacted at 260 ° C for 3 hours. After cooling to room temperature, the solid substance was separated, washed successively with 4,500 ml of pure water and acetone, and dried under vacuum for 20 hours while heating at 100 ° C. Table 1 shows the [ηinh] and the flow value of the obtained polyarylene sulfide.

Further, a composition composed of glass fibers [Asahi Glass Fiber Co., Ltd. “03MA497”] mixed with the polyarylene sulfide at a ratio of 40% by weight was prepared, and 127 × 12.7
Table 1 shows the measurement results by a microscope of the length of the tip burr when a 3.18 mm test piece was injection molded.

However, in Comparative Example 8, two kinds of test pieces were prepared in the same manner as above using a blend of unbranched polyphenylene sulfides having different molecular weights and the polyphenylene sulfide obtained by the above-mentioned operation. The length of the tip burr was measured as described above.

Claims (1)

[Claims] 1. In a polar solvent, at least one metal sulfide selected from the group consisting of (A) alkali metal sulfide and alkali metal hydrosulfide, (B) dihalogenated aromatic compound and (C) functional group. In the case of reacting an aromatic compound having three or more of the above with each other, the ratio of the component (B) to the component (A) used is 1.035 to 1.300 in a molar ratio [(B) / (A)].
And the ratio of the component (C) to the component (B) used is 0.003 to 0.0 at a molar ratio [(C) / (B)].
A method for producing a polyarylene sulfide characterized in that the content is within the range of 5.