JP3077205B2 - Manufacturing method of polyarylene sulfide - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a high-molecular-weight polyarylene sulfide (hereinafter abbreviated as PAS) in a high yield. More specifically, the present invention relates to a method for producing PAS using an additive characteristic of the reaction between an aromatic dihalide and an alkali metal sulfide.

[0002]

2. Description of the Related Art Polyphenylene sulfide (hereinafter PPS)
In recent years, PAS represented by) has been rapidly used in applications such as automobile parts and electric / electronic parts due to its high heat resistance, high chemical resistance, and excellent mechanical properties. However, PAS typified by PPS has a drawback of being brittle due to the difficulty of obtaining high molecular weight ones, and is applicable not only to films and fibers but also to parts requiring high toughness as injection molding materials. It is currently restricted.

[0003] In order to solve such a problem, many attempts have been made to produce a PAS having a higher molecular weight than before and to provide a PAS having a higher toughness. As a typical method, a method of adding an alkali metal carboxylate as a catalyst when reacting an alkali metal sulfide and an aromatic dihalide described in JP-B-52-12240, and JP-A-61-7332 are disclosed. A method of adding water during the polymerization of PAS described in the publication has been proposed.

JP-A-2-21520 discloses a method of obtaining a PAS by polymerizing a thiophenol derivative or a diphenyl disulfide derivative in the presence of an oxidizing agent.

[0005]

[Problems to be Solved by the Invention] However, Japanese Patent Publication No. 52-1
According to the method described in Japanese Patent No. 2240, the amount of the alkali metal carboxylate to be added is required to be approximately equimolar to the alkali metal sulfide, and PA having a higher polymerization degree is required.
In order to obtain S, there was a problem that expensive compounds such as lithium acetate and sodium benzoate had to be added.

On the other hand, according to the method described in JP-A-61-7332, it is necessary to add a large amount of water to the reaction system at a temperature of 250 ° C. or higher in order to obtain a PAS having a high degree of polymerization. ing. However, for this reason, the reactor
The structure must be able to withstand very high pressure and high temperature, and furthermore, there is a problem that the reaction must be continued for 10 hours or more under the condition of high temperature and high pressure. In addition, it is difficult to increase the polymer yield to 90% or more by this method, and there is a problem that a large amount of waste liquid containing aromatic compounds and sulfur must be treated.

As disclosed in JP-A-2-21520, there is a method of obtaining a PAS by polymerizing a thiophenol derivative or a diphenyl disulfide derivative in the presence of an oxidizing agent. It is industrially difficult to apply because of the large amount of agent required.

In view of the above situation, the present invention provides a PAS having a high degree of polymerization by adding a small amount of a polymerization aid, and does not require a reactor capable of withstanding extremely high pressure and high temperature. Thus, an object of the present invention is to develop a process for producing PAS in a high yield after completion of polymerization.

[0009]

Means for Solving the Problems In order to solve the problems, the present inventors have studied the polymerization mechanism of PAS in detail, and as a result, the problems of the present invention can be completely solved by adding a small amount of quinones to the reaction system. And reached the present invention.

That is, the present invention provides

[0011]

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(Wherein R1, R2, R3, and R4 each represent an alkyl group having 1 to 12 carbon atoms, an aromatic group, an alicyclic group, or a hydrogen atom, and X represents a halogen atom). This aromatic dihalide
Ride respect is to provide a process for producing polyarylene sulfide which comprises reacting an alkali metal sulfide in the presence of 0.05 to 5 mol% of the key non-class.

The aromatic dihalide used in the present invention is represented by the following formula.

[0014]

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(Wherein R ₁ , R ₂ , R ₃ and R ₄ each represent an alkyl group having 1 to 12 carbon atoms, an aromatic group, an alicyclic group, a hydrogen atom, or R 1 and R 2 or / and R3
And R4 each represent a part of a condensed aromatic. And X represents a halogen atom. Examples of R1, R2, R3, and R4 include a methyl group, an ethyl group, a propyl group, an isopropyl group, a cyclohexyl group, a phenyl group, and a hydrogen atom. And a hydrogen atom are preferred, and a methyl group and a hydrogen atom are particularly preferred. Further, the halogen atom represented by X is preferably a chlorine atom, a bromine atom or a fluorine atom, particularly preferably a chlorine atom.

As specific examples of the aromatic dihalide, for example,
1,2-dichlorobenzene, 1,3-dichlorobenzene, 1,4-dichlorobenzene, 1,2-dibromobenzene, 1,3-dibromobenzene, 1,4-dibromobenzene, 1-bromo- 2-chlorobenzene, 1-bromo-3-chlorobenzene, 1-bromo-4-chlorobenzene, 1,4-dichloro-3-phenylbenzene, 2,5
-Dichlorotoluene, 2,5-dichloro-p-xylene, 1-ethyl-4-isopropyl-2,5-dibromobenzene, 2,3,5,6-tetramethyl-1,4-dichlorobenzene, 3,5-dichlorobenzoic acid, 1,4-
Examples thereof include dichloronaphthalene and 1, -methoxy-2,5-dichlorobenzene. Of these, 1,3-dichlorobenzene, 1,4-dichlorobenzene, 2,5-dichlorotoluene, and 2,5-dichloro-p-xylene are preferred examples. Not only one kind of these aromatic polyhalogen compounds but also two or more kinds can be used.

If the amount is small, other aromatic dihalides, such as 4,4'-dichlorodiphenylsulfone, 4,4'-dichlorobenzophenone, and 4,4'-dichlorodiphenyl ether, may be used. No problem.

If the amount is further small, a polyhalogenated aromatic compound of trihalo or higher can be used in combination.
As the polyhalogenated aromatic compound, 1,3,5-trichlorobenzene and 1,2,4-trichlorobenzene are most preferred. Furthermore, a small amount of a monohalide can be used in combination for the purpose of controlling the molecular weight of PAS or stabilizing the terminal. Preferred monohalides include monochlorobenzene, 1-chloronaphthalene, 2-chloronaphthalene, methyl chloride, 4-chlorophenylphenylsulfone, 4-chlorobenzophenone, benzyl chloride and the like.

The alkali metal sulfide used in the present invention has a general formula M ₂ S (where M represents an alkali metal).
Is represented by Specific examples include lithium sulfide, sodium sulfide, potassium sulfide, rubidium sulfide, cesium sulfide, and the like. These alkali metal sulfides are often used in the form of anhydrides, hydrates or aqueous mixtures, and can also be used in a mixture of two or more. Of these, sodium sulfide, which is particularly easily available in high purity, is preferable. This sodium sulfide can be used in the form of anhydride, 9 hydrate, 6 hydrate, 5.5 hydrate, aqueous solution and the like. Alkali metal bisulfide and alkali metal thiosulfate may be included as impurities in the alkali metal sulfide, so a small amount of alkali metal hydroxide can be added to the alkali metal sulfide to remove these. It is.

In the present invention, a mixture of an alkali metal hydrosulfide and an alkali metal hydroxide can be used instead of the above-mentioned alkali metal sulfide.

The amount of the alkali metal sulfide used is 0.9 to 0.9% in terms of the total sulfur content per mole of aromatic dihalide.
1.1 mol, preferably 0.95 to 1.02 mol. When the amount is less than 0.9 mol or when the amount is 1.1 mol or more, the molecular weight of PAS is not increased, and neither is preferable.

The quinones used in the present invention refer to compounds having the following basic structural formula in the molecule.

[0023]

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In the present invention, any compound having a basic structure represented by the formula can be expected to have a sufficient effect, but quinones having the structure represented by the following formula exhibit high effects.

[0025]

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In the formula, R ₅ , R ₆ , R ₇ and R ₈ are each hydrogen, halogen, an alkyl group, an alkylene group,
An aryl group, a substituent such as a cyano group, also R _5,
R ₆ or / and R ₇ and R ₈ may be a part of the condensed aromatic group.

Specific examples of preferred quinones include 1,4
-Benzoquinone (p-benzoquinone), methylbenzoquinone (p-toluquinone), 2,5-dimethylbenzoquinone (p-xyloquinone), 2,6-dimethylbenzoquinone, 2,3-benzoquinone, 2,3,5-trimethylbenzoquinone, 2,3,5,6-tetramethylbenzoquinone (duloquinone), 2-isopropyl-5-methylbenzoquinone (thymoquinone), tetrafluorobenzoquinone, difluorobenzoquinone, monofluorobenzoquinone, tetrachlorobenzoquinone, dichlorobenzoquinone, chlorobenzoquinone, tetracyano Benzoquinone,
Dicyanobenzoquinone, monocyanobenzoquinone, 1,
4-naphthoquinone, 2-methyl-1,4-naphthoquinone, 2,3-dimethyl-1,4-naphthoquinone, 8-methyl-1,4-naphthoquinone, anthraquinone, 2,6
Dihydroxyanthraquinone, anthraquinone-1,
5-disulfonic acid, heptafluoroanthraquinone and the like. Of these, benzoquinone (p-benzoquinone), methylbenzoquinone (p-toluquinone), 2,
5-dimethylbenzoquinone (p-xyloquinone), 2,
6-dimethylbenzoquinone, 2,3-benzoquinone,
2,3,5-trimethylbenzoquinone, 2,3,5,6
-Tetramethylbenzoquinone (duloquinone), 2-isopropyl-5-methylbenzoquinone (thymoquinone), 1,4-naphthoquinone, 2,3-dimethyl-1,
4-Naphthoquinone, anthraquinone and the like are particularly preferable examples.

The addition amount of quinones is 0.05-5 mol
%, Preferably 0.5-3 mol%.
, The degree of polymerization of the produced polymer is effectively increased,
Time can be shortened .

When the reaction between the aromatic dihalide and the alkali metal sulfide is carried out in the presence of quinones, it is possible to carry out the reaction without using a solvent. Obtainable. The preferred solvent is not particularly limited as long as it is a so-called polar organic solvent, but a so-called aprotic organic solvent is more preferred. Examples of preferred solvents include dimethyl sulfoxide, dimethylacetamide, dimethylformamide, N-methylpyrrolidone, N-ethylpyrrolidone, N-methylimidazole,
N-methylcaprolactam, tetramethylurea, hexamethylphosphoric triamide, dimethylimidazolidinone,
N-cyclohexylpyrrolidone, sulfolane, diphenylsulfone, etc., among which dimethylsulfoxide, N-methylpyrrolidone, N-methylcaprolactam, dimethylimidazolidinone, N-cyclohexylpyrrolidone, sulfolane and the like are particularly preferred. , N-cyclohexylpyrrolidone and sulfolane are most preferred.

The amount of the solvent used is preferably 0.1 to 10 cubic decimeters per mole of the alkali metal sulfide.

It is also possible to add a conventionally known polymerization aid such as an alkali metal carboxylate as long as the polymerization is not hindered. The addition amount of the alkali metal carboxylate is 0.5-10 to 1 mol of the aromatic dihalide.
Mol%, more preferably 1-5%.

When quinones are used, not only the reaction solvent but also reaction conditions such as reaction time and reaction temperature can be set quite freely. Although the reaction temperature is not necessarily limited, 5
0 ° C to 350 ° C, preferably 100 ° C to 300 ° C
It is preferable to carry out in the range up to ° C. When the reaction is carried out at a temperature of 350 ° C. or higher, it is difficult to obtain PAS having a high degree of polymerization, which is not preferable. The reaction time varies depending on the reaction temperature, but is not limited to 0.1.
When the polymerization is completed within 2 to 15 hours, preferably 0.5 to 10 hours, a polymer having a high degree of polymerization is obtained. Under the ordinary conditions, the polymerization is completed in about 3 hours, and a polymer having a high degree of polymerization can be obtained.

The reaction procedure may be the same as that of a conventionally known general polymerization procedure for PAS, but when quinones are added, the reaction can be carried out under slightly mild conditions. As a general procedure, an alkali metal sulfide or an alkali metal hydrosulfide / alkali metal hydroxide serving as a sulfur source is added to a reaction solvent, and water is distilled off by distillation or the like as necessary. When quinones are added, the amount of water present can be set relatively freely, but the molar ratio of water to alkali metal sulfide is from 0.9: 1 to 15: 1, preferably from 0.95: 1. The ratio is 5: 1, more preferably 1: 1 to 3: 1. After adjusting the amount of water, an aromatic dihalide is added and heated to a predetermined temperature to cause a reaction. Quinones may be added at any stage during the reaction. For example, a method of adding a sulfur source at the stage of putting it in a solvent, a method of adding immediately after distilling water, a method of adding with an aromatic dihalide, a method of adding while heating to the reaction temperature, after reaching the reaction temperature Examples of the method include a method of adding water, and a method of adding water immediately after water is distilled off, and a method of adding water together with an aromatic dihalide are preferable. The addition of quinones in several stages also gives favorable results. After completion of the reaction, the polymer can be isolated by a conventionally known method. For example, a large amount of water is added before cooling at the end of a predetermined reaction time, and then cooling is performed. When the temperature of the reaction system reaches room temperature, the polymer and the solvent are separated by a 100-mesh sieve. The desired PAS can be obtained by sufficiently washing the polymer with water and drying.

Usually, the polymer yield can be at least 85% based on the aromatic dihalide, and 90-95% or more if the conditions are the same.

It is not always necessary to separate the added quinones, and there is no problem even if they remain in the polymer. When it is necessary to remove quinones, it may be washed with an appropriate solvent.

The melt viscosity of the PAS polymerized in the present invention is:
There is no particular limitation, and PAS having any melt viscosity can be produced, but it is usually 5 to 10,000 Pascal-second (315
(° C, shear rate: 400 / sec).

The polymer of the present invention may contain ordinary antioxidants, heat stabilizers, lubricants, crystal nucleating agents, ultraviolet inhibitors, coloring agents, flame retardants, etc. within a range that does not impair the effects of the present invention. Additives and small amounts of other polymers can be added, and for the purpose of controlling the degree of crosslinking of the polymer, ordinary peroxides and metal thiophosphinates described in JP-A-59-131650 are used. A crosslinking accelerator such as a salt or JP-A-58-204045, JP-A-58-20404.
It is also possible to add a crosslinking inhibitor such as dialkyltin dicarboxylate and aminotriazole described in JP-A-6-No.

If necessary, a fibrous and / or granular reinforcing agent can be used in the polymer of the present invention.
It can be blended in a range not exceeding 300 parts by weight based on 100 parts by weight of the total of the resin components, and usually 10 to 3 parts by weight.
By mixing in the range of 00 parts by weight, it is possible to improve strength, rigidity, heat resistance, dimensional stability and the like. Examples of such a fibrous reinforcing agent include glass fiber, alumina fiber, silicon carbide fiber, ceramic fiber, asbestos fiber, masonry fiber, inorganic fiber such as metal fiber, and carbon fiber. In addition, examples of granular reinforcing agents include wollastenite, sericite, kaolin, mica, clay,
Silicates such as talc and alumina silicate, alumina,
Metal oxides such as silicon chloride, magnesium oxide, zirconium oxide and titanium oxide; carbonates such as calcium carbonate, magnesium carbonate and dolomite; sulfates such as calcium sulfate and barium sulfate; glass beads; boron nitride;
Examples include silicon carbide and silica, which may be hollow. Two or more of these reinforcing agents can be used in combination, and if necessary, can be used after being pretreated with a silane-based or titanium-based coupling agent.

The means for preparing the composite composition with the filler as described above is not particularly limited, but is melt-kneaded in an extruder at a temperature not lower than the melting point of the PAS resin using a resin component and a reinforcing agent, and then pelletized. The method is representative. The melt-kneading temperature varies depending on the polymer, but is preferably from 270 ° C to 400 ° C.

Now, the present invention will be described in further detail with reference to Examples.

[0041]

EXAMPLES Example 1 In an autoclave, 3.26 kg of sodium sulfide (25 mol, containing about 40% of water of crystallization), 4 g of sodium hydroxide,
And N-methylpyrrolidone (hereinafter abbreviated as NMP) 7.
9 kg was charged and the temperature was gradually raised to 200 ° C. with stirring to remove about 0.95 kg of distillate water containing 0.81 kg of water. 3.75 of 1,4-dichlorobenzene were added to the residual mixture.
kg (25.5 mol), 30 g of 1,4-benzoquinone
(1.2 mol% based on 1,4-dichlorobenzene) and 2 kg of NMP were added, and the mixture was heated at 260 ° C. for 1 hour. After the completion of the reaction, 2 kg of water was added while cooling to room temperature. A 100 mesh sieve was used to separate the polymer from the reaction mixture. Wash the polymer several times with distilled water,
Further, it was washed twice with hot water at 130 ° C. The polymer was dried by heating under vacuum and the yield was determined.
%)Met. 315 with the Koka type flow tester
At a shear rate of 400 / sec.
6 Pascal-seconds.

Comparative Example 1 Example 1 except that 1,4-benzoquinone was not added.
Polymerization was carried out in the same manner as described above. The yield is 1.90 kg (69
%), Stinking. The polymer was measured for viscosity at 315 ° C. and a shear rate of 400 / sec with a Koka type flow tester to find that the viscosity was 10.2 Pascal · sec. As compared with the examples, the molecular weight of the polymer was clearly lower.

Example 2 Example 1 was repeated except that the quinones were changed as shown in Table 1.
The same was done. The results are shown in Table 1. The viscosity in Table 1 is
It was measured at 315 ° C. at a shear rate of 400 / sec, and the unit was expressed in Pascal · sec.

[0044]

[Table 1]

Examples 5 and 6 and Comparative Examples 2, 31 The same procedure as in Example 1 was carried out except that the amount of 1,4-benzoquinone was changed as shown in Table 2. Table 2 shows the results. The viscosity measurement conditions and units are the same as in Table 1.

[0046]

[Table 2]

Examples 7, 8 The procedure of Example 1 was repeated except that 1,4-dichlorobenzene was changed as shown in Table 3. Table 3 shows the results.
The viscosity measurement conditions are the same as in Table 1.

[0048]

[Table 3]

Example 9 Example 1 except that the solvent was changed from NMP to sulfolane
The same was done. The viscosity of the obtained polymer measured at 315 ° C. and a shear rate of 400 / sec with a Koka type flow tester was 871 Pascal · sec.

Comparative Example 4 In an autoclave, 3.26 kg of sodium sulfide (25 mol, containing about 40% of water of crystallization), 4 g of sodium hydroxide,
And 7.9 kg of NMP, and the temperature was gradually raised to 200 ° C. while stirring to remove about 0.95 kg of distillate water containing 0.81 kg of water. 3.75 kg (25.5 mol) of 1,4-dichlorobenzene and NMP were added to the residual mixture.
2 kg was added and heated at 260 ° C. for 1 hour. Then, while maintaining the temperature of 260 ° C. using a pump,
kg was added. After the addition, the reaction was continued for another 15 minutes and cooled to room temperature. After cooling, the inside of the autoclave was examined, and only a very stinking liquid was found, and no polymer was obtained.

From this comparative example, it was found that in the method of adding water during the polymerization, a polymer having a high degree of polymerization could not be obtained when the polymerization time was shortened.

[0052]

According to the polymerization method of the present invention, a polymer having a high degree of polymerization can be obtained in a short time and with a high yield only by adding a small amount of an additive, as compared with the conventional polymerization method.

Continuation of the front page (56) References JP-A-3-221528 (JP, A) JP-A-2-212520 (JP, A) Polymer (Korea), Dec. 1989, vol. 13, No. 10, p. 866-873 (58) Fields investigated (Int. Cl. ⁷ , DB name) C08G 75/00-75/32 CA (STN) REGISTRY (STN)

Claims (1)

(57) [Claims] (1) Formula (1) (Wherein R1, R2, R3, and R4 each have 1 to 1 carbon atoms)
Alkyl groups of up to 12, an aromatic group, alicyclic group, represents a hydrogen atom, and X is an aromatic dihalide represented by each represents) a halogen atom, to the aromatic dihalide
Preparation of polyarylene sulfide which comprises reacting an alkali metal sulfide in the presence of 0.05 to 5 mol% of the key non-class.