JP2924202B2 - Method for producing polyarylene sulfide - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention makes it possible to produce high-molecular-weight polyarylene sulfide suitable as a material for various molded articles, films, sheets, fibers or mechanical parts, electric and electronic parts in a short time and economically. It is about the method.

[0002]

2. Description of the Related Art Polyarylene sulfide is excellent in heat resistance and chemical resistance, and also has good mechanical properties, flame retardancy, dimensional stability, workability, etc., so that it can be used as engineering plastics for automobile parts, electric and It is widely used in various fields such as electronic parts, precision machine parts, and OA equipment parts.

As a method for producing polyarylene sulfide, a method is known in which a dihalogenated aromatic compound is reacted with sodium sulfide in an organic amide solvent such as N-methylpyrrolidone. (Japanese Patent Publication No. 45-3368
No.)

However, in this method, the molecular weight of the obtained polyarylene sulfide does not become sufficiently large. For example, the weight average molecular weight is 20,000 or less (the weight average molecular weight can be measured by a GPC method, a light scattering method, or the like at a high temperature of 200 ° C. or more of a solution of the polymer in α-chloronaphthalene). For this reason, there is a problem that it is difficult to form into a film, a sheet, a fiber, or the like due to a low melt viscosity.

Various methods have been proposed to improve this point and obtain polyarylene sulfide having a high degree of polymerization. Typical examples thereof include a method in which the reaction is carried out in two steps in the presence of water (Japanese Patent Application Laid-Open No. 61-7332) and a method in which an alkali metal carboxylate is used as a polymerization aid (Japanese Patent Publication No. 52-12240). ) Has been proposed.

Although the polyarylene sulfide obtained by these methods has a high degree of polymerization, for example, the weight average molecular weight is about 40,000 to 50,000, and the degree of polymerization is 400 to 50,000.
500, which is not yet sufficient, and in order to obtain a polyarylene sulfide having a higher polymerization degree having a molecular weight of 60,000 or more and a polymerization degree of 600 or more, the polymerization time must be extended to 12 hours or more, or a polymerization aid Is required to be used in a large amount such as 0.5 mol or more per mol of the sulfur source used. As a result, there is a problem in economical aspects such as an increase in the production cost of polyarylene sulfide.

In order to simply increase the melt viscosity or the molecular weight, there is a method of introducing a crosslinked structure using a compound having three or more halogen atoms (Japanese Patent Publication No. 54-8 / 1979).
No. 719) The high-molecular-weight polyarylene sulfide obtained by this method has a problem that when the amount thereof is large, the linearity is impaired and the spinnability and the film-forming property become poor.

[0008]

SUMMARY OF THE INVENTION The present invention overcomes the drawbacks of the conventional method for producing a high molecular weight polyarylene sulfide and produces a high molecular weight polyarylene sulfide in a short time and with a high yield. It provides a method. Here, the high molecular weight means a molecular weight of about 60,000 or more, and the short time means a polymerization time of less than 12 hours.
A high yield means at least 80% or more.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to produce a polyarylene sulfide by performing polymerization in the presence of a regulated amount of water and an alkali metal carboxylate while controlling the rate of temperature rise of the reaction system. Achieved by

That is, in the present invention, a sulfur source selected from alkali sulfide, alkali hydrosulfide, and hydrogen sulfide in an organic polar solvent, and an alkali metal other than alkali sulfide is used as the sulfur source. a hydroxide and polyhalogenated aromatic compounds, also when using the sodium sulfide as the sulfur source is by reacting a polyhalogenated aromatic compound in a method for obtaining a polyarylene sulfide, polyhalogenated aromatic Group compounds are dihalogenated
100 to 99.5 mol% of aromatic compound and 3 or more
Polyhalogenated aromatic compound having a halogen atom 0
0.5 mol%, when the reaction solution is heated from a temperature of 220 ° C. or less to 260 ° C. or more, in the presence of less than 0.3 mol of water and an alkali metal carboxylate per 1 mol of S in the sulfur source. , average reaction at a heating rate of 0.5 ° C. / min or less <br/> lines of stomach, remaining the polyhalogenated aromatic compound after completion of the reaction
It is intended to provide a process for producing polyarylene sulfide, wherein the amount is 2.5 mol% or less of the supplied amount .

[0011]

DETAILED DESCRIPTION OF THE INVENTION The polyarylene sulfide produced by the present invention is represented by the formula

Embedded image Is a homopolymer or copolymer having a repeating unit as a main constituent unit. As long as this repeating unit is the main constituent unit,

Embedded image And a small amount of a branched or cross-linked bond represented by

As Ar

Embedded image

Embedded image (R ₁ and R ₂ are selected from hydrogen, an alkyl group, an alkoxy group, and a halogen group). Particularly preferred polyarylene sulfides include a p-phenylene unit as a main structural unit of the polymer.

Embedded image (Hereinafter also referred to as PPS), polyphenylene sulfide sulfone, and polyphenylene sulfide ketone containing 90 mol% or more.

The sulfur source of the present invention includes alkali sulfide,
At least one selected from alkali hydrogen sulfide and hydrogen sulfide can be used as a sulfur source. Examples of the alkali sulfide include sodium sulfide, potassium sulfide, lithium sulfide, rubidium sulfide, and cesium sulfide, and among them, sodium sulfide is preferably used. As the alkali hydrosulfide, sodium hydrosulfide, potassium hydrosulfide,
Among them, lithium hydrosulfide, rubidium hydrosulfide, cesium hydrosulfide and the like are preferable, and sodium hydrosulfide is preferably used.

The alkali metal hydroxide of the present invention includes:
Sodium hydroxide, potassium hydroxide, lithium hydroxide,
Examples thereof include rubidium hydroxide and cesium hydroxide, and among them, sodium hydroxide is preferably used.

When alkali sulfide is used as the sulfur source, the combined use of alkali metal hydroxide is not different from the case where no alkali metal hydroxide is used. However, alkali hydrosulfide (NaS
In the case of H) and hydrogen sulfide (H ₂ S), the degree of polymerization does not increase unless used together. That is, it is necessary that the sulfur source at the time of PPS polymerization be present as an alkali sulfide. The reason is considered as follows. For example, when the alkali metal is Na: sodium sulfide (Na ₂ S) ─── a sufficient degree of polymerization sodium hydrosulfide (NaSH) + sodium hydroxide (NaOH) → Na ₂ S が a sufficient degree of polymerization hydrogen sulfide (H ₂ S) + sodium hydroxide (2NaOH) → Na ₂ S ─── Sufficient degree of polymerization

The polyhalogenated aromatic compound of the present invention refers to a compound having two or more halogen atoms and a molecular weight of less than 1,000. Specific examples include p-dichlorobenzene,
m-dichlorobenzene, o-dichlorobenzene, 1,
3,5-trichlorobenzene, 1,2,4-trichlorobenzene, 1,2,4,5-tetrachlorobenzene, hexachlorobenzene, 2,5-dichlorotoluene, 2,
5-dichloro-p-xylene, 1,4-dibromobenzene, 1,4-dichloronaphthalene, 1,5-dichloronaphthalene, 1-methoxy-2,5-dichlorobenzene,
4,4'-dichlorobiphenyl, 3,5-dichlorobenzoic acid, 4,4'-dichlorodiphenyl ether, 4,
There are polyhalogen-substituted and aromatic compounds such as 4'-dichlorodiphenylsulfone and 4,4'-dichlorodiphenylketone. Among them, p-dichlorobenzene, 4,4
4'-Dichlorodiphenyl sulfone and 4,4'-dichlorodiphenyl ketone are preferably used.

Examples of the organic polar solvent of the present invention include N-methylpyrrolidone, N-methylcaprolactam, N, N-dimethylacetamide, N, N-dimethylformamide, hexamethylphosphoric triamide, dimethylsulfone, tetramethylenesulfoxide and the like. In particular, N-methylpyrrolidone is preferably used.

The alkali metal carboxylate of the present invention includes lithium acetate, sodium acetate, potassium acetate, lithium propionate, sodium propionate, lithium 2-methylpropionate, rubidium butyrate, lithium valerate, sodium valerate, and hexane. Cesium acid, lithium heptanoate, lithium 2-methyloctanoate, potassium dodecanoate, rubidium 4-ethyltetradecanoate, sodium octadecanoate, sodium heneicosanoate, lithium cyclohexanecarboxylate, cesium cyclododecanecarboxylate, 3-methylcyclopentanecarboxylate Sodium salt, potassium cyclohexyl acetate,
Potassium benzoate, lithium benzoate, sodium benzoate, potassium m-toluate, lithium phenylacetate, sodium 4-phenylcyclohexanecarboxylate, potassium p-tolylacetate, lithium 4-ethylcyclohexylacetate, other similar salts, and Mixtures thereof, among which lithium acetate, sodium acetate,
Sodium benzoate and lithium benzoate are preferably used.

In the reaction of the present invention, a polymerization reaction temperature of 220 ° C. or lower is not preferable because the polymerization reaction hardly occurs, and a temperature of 260 ° C. or higher is preferable in order to further promote the polymerization reaction. Further, when the temperature is raised from a temperature of 220 ° C. or lower to a temperature of 260 ° C. or higher, the temperature is preferably 0.5 ° C./min or less. This is not preferable because the degree of polymerization of polyarylene sulfide does not increase.

In the reaction of the present invention, the water present in the system at the initial stage of the reaction is preferably less than 0.3 mol per mol of S in the sulfur source, and the polyarylene obtained when more water is present is obtained. The degree of polymerization of the sulfide is not increased, and the corrosion of the reaction vessel is undesirably increased.

In the reaction of the present invention, a crosslinked structure can be introduced by using a compound having three or more halogen atoms, but the amount added is 0.5 mol of the total amount of the polyhalogenated aromatic compound. % Or less is preferable. It is not preferable to add a compound having three or more halogen atoms in an amount of 0.5 mol% or more, since the resulting polyarylene sulfide has poor spinnability and film-forming properties.

In the reaction of the present invention, an auxiliary agent such as an organic sulfonate, an alkaline earth metal oxide, an alkali metal phosphate, or an alkaline earth metal phosphate may be added. , An inorganic acid, a terminal blocking agent and the like can be added. Further, water can be added in the latter stage of the polymerization.

[0023] The residual amount of the polyhalogenated aromatic compound in the reaction solution after the reaction in the present invention is calculated by dividing the supply amount by 2.
It is preferably at most 5 mol%, especially from 0.5 to 2.
0 mol% is preferred. If it exceeds 2.5 mol%, the molecular weight of the obtained polyarylene sulfide is not preferred.

The polyarylene sulfide reacted in the present invention is obtained by washing with a polar organic solvent or water and drying. The obtained polyarylene sulfide has a high molecular weight, and when used for fibers, films, molding resin compositions and the like, molded articles having excellent mechanical properties can be obtained.

In addition, inorganic fillers such as glass fiber, carbon fiber, titanium oxide and calcium carbonate, antioxidants, heat stabilizers, ultraviolet absorbers, coloring agents and the like can also be added.

Also, polyamide, polysulfone, polyphenylene oxide, polycarbonate, polyethersulfone, polyethylene terephthalate, polybutylene terephthalate, polyethylene, polypropylene, polytetrafluoroethylene, polyetherester elastomer, polyetheramide elastomer, polyamideimide, polyacetal, polyimide And the like.

[0027]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. The melt flow rate in the present invention is A
Temperature 315.6 according to STM D-12380-70
It was measured at a temperature of 5 ° C. and a load of 5 kg. The unit is g / 10
Minutes.

Example 1 In a 1-liter autoclave equipped with a stirrer, 245.0 g (1.02 mol) of sodium sulfide / 9-hydrate, sodium acetate 2
4.6 g (0.3 mol), about 48% aqueous sodium hydroxide solution 2.5 g (0.03 mol) and N-methyl-2-
198 g (2.0 mol) of pyrrolidone was charged and gradually heated to 205 ° C. over about 3 hours while passing nitrogen to distill 164 g of a distillate mainly composed of water. The amount of water remaining in the system was 0.14 mol.

The reaction vessel was cooled to 180 ° C., and 147 g (1.0 mol) of p-dichlorobenzene and N-methyl-
149 g (1.5 mol) of 2-pyrrolidone was added, the mixture was sealed under nitrogen gas pressure, and the temperature was raised to 210 ° C.

The reaction vessel is heated from 210 ° C to 225 ° C.
The temperature was raised at a rate of 5 ° C./min, and then 0.3 ° to 270 ° C.
The temperature was raised at a rate of ° C / min, and the reaction was carried out at 270 ° C for 110 minutes. The time from the internal temperature of 210 ° C. to the end of the polymerization reaction is 290
Minutes.

After the reaction vessel was slowly cooled at a rate of 1 ° C./min, the contents were taken out, and the amount of remaining p-dichlorobenzene was analyzed by gas chromatography to be 1.2 mol%. . The contents were washed with 70 g of N-methyl-2-pyrrolidone at 70 ° C, washed six times with 700 g of water at 70 ° C, and dried at 120 ° C under reduced pressure.

The yield of the obtained polyphenylene sulfide was 89%, and the melt flow rate was 64 g / 10 minutes. During the dehydration step in this operation, the amount of hydrogen sulfide scattered was 2.0 mol%.

Example 2 After the reaction vessel was sealed, 0.3 ° C./210° C. to 270 ° C.
The same operation as in Example 1 was carried out except that the temperature was raised at a rate of 1 minute and the reaction was carried out at 270 ° C. for 70 minutes. The time from the internal temperature of 210 ° C. to the end of the polymerization reaction was 270 minutes. 84% yield
The melt flow rate of the polyphenylene sulfide obtained in the above was 76 g / 10 minutes, and the remaining p-dichlorobenzene was 1.4 mol%.

Example 3 Into a 1 liter autoclave as in Example 1, 45%
127.1 g (1.02 mol) of sodium hydrosulfide, 40.0 g (1.0 mol) of sodium hydroxide, 24.6 g (0.30 mol) of sodium acetate and N-methyl-2-
Example 1 was charged with 198 g (2.0 mol) of pyrrolidone.
Then, 66 g of a distillate mainly composed of water was distilled off. The amount of water remaining in the system was 0.22 mol.

The reaction vessel was cooled to 180 ° C., and 147 g (1.0 mol) of p-dichlorobenzene and N-methyl-
149 g (1.5 mol) of 2-pyrrolidone was added, the mixture was sealed under nitrogen gas pressure, and the temperature was raised to 210 ° C.

Next, from 210 ° C. to 225 ° C., 0.5 ° C. /
The temperature is raised at a rate of 225 ° C. for 30 minutes, and the temperature is raised to 270 ° C. at a rate of 0.3 ° C./min.
The reaction was performed at 0 ° C. for 70 minutes.

After completion of the reaction, 18 g of water was added at a rate of 1 ml / min while cooling the reaction vessel at 1 ° C./min. Thereafter, cooling, washing and drying were performed in the same manner as in Example 1 to obtain polyphenylene sulfide with a yield of 87%. The remaining p-dichlorobenzene was 1.6 mol%, and the melt flow rate was 52%.
g / 10 minutes. The time from the internal temperature of 210 ° C. to the end of the polymerization reaction was 280 minutes.

Example 4 After the reaction vessel was sealed, the same operation as in Example 3 was carried out except that the reaction was carried out at 225 ° C. for 106 minutes, then at a rate of 0.5 ° C./min and reacted at 270 ° C. for 55 minutes. Done. Internal temperature 210 ° C
The time from to the end of the polymerization reaction was 281 minutes. The melt flow rate of the polyphenylene sulfide obtained at a yield of 87% was 85 g / 10 min, and the remaining p-dichlorobenzene was 1.9 mol%.

Example 5 Polymerization was carried out in the same manner as in Example 3, except that 155.9 g (1.0 mol) of p-dibromobenzene was used instead of p-dichlorobenzene. The remaining p-dibromobenzene was 0.7 mol%, and a polymer having a melt flow rate of 83 g / 10 min was obtained. Here, the temperature was raised to 270 ° C. at a rate of 0.5 ° C./min, and when the temperature reached 270 ° C., the reaction vessel started cooling at 1 ° C./min. The time from the internal temperature of 210 ° C. to the end of the polymerization reaction was 150 minutes.

Example 6 In Example 1, 45%
The same polymerization operation was performed except that 2.0 g (0.016 mol) of sodium hydrosulfide was used. 9 particulate polymer
2% yield and a melt flow rate of 48 g / 1
It was 0 minutes. During the dehydration step in this operation, the scattered hydrogen sulfide was 2.8 mol% per sodium hydrosulfide.

COMPARATIVE EXAMPLE 1 In Example 1, 0.6 ° C./210° C./270° C.
The same operation as in Example 1 was carried out except that the temperature was raised at a rate of 1 minute and the reaction was carried out at 270 ° C. for 170 minutes. The melt flow rate of the obtained polyphenylene sulfide was 624 g / 10 minutes, and the remaining p-dichlorobenzene was 1.0 mol%. The polymer yield was 79%
Met.

Comparative Example 2 When p-dichlorobenzene was added, 18 g of water (1
(Mol) was performed in the same manner as in Example 1. The melt flow rate of the obtained polyphenylene sulfide was 1100 g / 10 minutes, and the remaining p-dichlorobenzene was 0.4 mol%. The yield of the polymer was 63%.

Comparative Example 3 The same operation as in Example 1 was carried out except that sodium acetate was not added. The melt flow rate of the obtained polyphenylene sulfide was 1400 g / 10 minutes, and the remaining p-dichlorobenzene was 1.5 mol%. The yield of the polymer was 80%.

Comparative Example 4 The same operation as in Example 1 was carried out except that 150 g (1.02 mol) of p-dichlorobenzene was added. The resulting polyphenylene sulfide has a melt flow rate of 7
P-Dichlorobenzene remaining at 30 g / 10 minutes was 2.9 mol%. The polymer yield was 82%.
Met.

Comparative Example 5 The same procedure as in Example 1 was carried out except that 145.5 g (0.99 mol) of p-dichlorobenzene and 1.8 g (0.01 mol) of 1,2,4-trichlorobenzene were added. The melt flow rate of the polyphenylene sulfide obtained by the operation was 45 g / 10 min, and the remaining p-dichlorobenzene was 1.2 mol%. The yield of the polymer was 81%. However, with this polymer, yarn breakage occurred during spinning.

Comparative Example 6 A 1-liter container having a withdrawal cock at the bottom was used.
A dehydration operation was performed using the same prescription as in Example 1. After cooling the system to 180 ° C., 147 g of p-dichlorobenzene
(1.0 mol) and 149 g of N-methylpyrrolidone were added, and the mixture was sealed under a nitrogen atmosphere, heated to 210 ° C., and kept constant. Take out the contents and use a cock for about 50g each 5,
After 10 and 20 hours, the polymer was taken out, the powdery polymer was washed with water, dried, and the melt flow rate was measured.

[Table 1] ─────────────────────────────── Melt flow rate Molecular weight ───────────後 After 5 hours 5,000 or more 15,000 or less 10 5,000 or more ２０ 20 3800 17500 ──────────────── ───────────────

Comparative Example 7 The same polymerization operation as in Example 3 was carried out except that sodium hydroxide was used. 7 in the dehydration process
At the same time as obtaining 0 g of distillate, 3.5 mol% of hydrogen sulfide was scattered per sodium bisulfide used. The polymer after washing is in a powder form, and has a melt flow rate of 3200 g /
10 minutes. On the other hand, 210-270 ° C in this system
The temperature was raised at a rate of 0.8 ° C./min until the melt flow rate of the finely divided polymer obtained by the same operation was as high as 6700 g / 10 min.

Next, the physical properties of the molded articles obtained by directly molding the polymers obtained in Example 1 and Comparative Example 1 using the following injection molding machine will be described. Sumitomo Nestal SG75 Injection temperature 320 ℃ Mold temperature 150 ℃ Test piece JIS-K7113

[Table 2] Example 1 Comparative Example 1 Tensile strength (kg / cm ² ) 891 770 Elongation (%) 12.5 3.8 Weld strength (kg / cm ² ) 820 750 Bending strength (kg / cm ² ) 1450 1412 Impact strength No breakage 29 No notch (kg · cm / cm ² ) (60 or more) ────────── ─────────────────────────

The polymers in the working (comparative) examples all have a glass transition temperature of 89 to 92 ° C. and a melting point of 275 to 295 ° C., and are presumed to have a polyphenylene sulfide structure as a repeating unit.

In the working (comparative) examples, the value of the melt flow rate is described, but there is a certain relationship between this value and the molecular weight (or the degree of polymerization). The molecular weight is 108 × the degree of polymerization. Then, the melt flow rate and the molecular weight of the polymer obtained in each execution (comparative) example are shown in the table below.

[Table 3]

As can be seen from the above table, in the case of Examples 1 to 6 of the present invention, the melt flow rate is small and the degree of polymerization of the obtained polymer is high. Example 1
During the dehydration step, 2.0 mol% of hydrogen sulfide was scattered, and the hydrogen sulfide scattered in Example 6 was 2.8 mol%. ) To reduce the loss of the sulfur source.

In contrast to Examples 1 to 6 above, Comparative Examples 1 to 7
(Comparative Example 1), when the polymerization reaction temperature is 220 ° C. or lower (Comparative Example 6), and when a large amount of water is present in the system during the polymerization reaction (Comparative Example 2). When no alkali metal carboxylate is present (Comparative Example 3), when the residual amount of the polyhalogenated aromatic compound is large (Comparative Example 4), or when a source other than sodium sulfide is used as the sulfur source and the alkali metal water is used. When no oxide is used (Comparative Example 7), polyarylene sulfide having a high degree of polymerization cannot be obtained. When a large number of crosslinked structures are introduced (Comparative Example 5), the degree of polymerization is increased, but the properties of the polymer are impaired.

[0053]

In the method for producing polyarylene sulfide, the rate of temperature rise of the reaction system has been widely set as a general description in the conventional examples, but is controlled under specific conditions as in the present invention. As a result, a polyarylene sulfide having a high polymerization degree can be obtained in a short time (less than 12 hours, for example, 210 minutes to 280 minutes), and the yield of the polyarylene sulfide obtained as a by-product is also improved.

Continued on the front page (58) Fields surveyed (Int. Cl. ⁶ , DB name) C08G 75/02 CA (STN) REGISTRY (STN) WPI / L (QUESTEL)

Claims (2)

(57) [Claims] 1. A sulfur source selected from an alkali sulfide, an alkali hydrosulfide, and hydrogen sulfide in an organic polar solvent, and an alkali metal hydroxide when using a source other than the alkali sulfide as the sulfur source. When a polyhalogenated aromatic compound and an alkali sulfide are used as the sulfur source, a method for reacting the polyhalogenated aromatic compound with a polyhalogenated aromatic compound to obtain a polyarylene sulfide is used.
Genogenated aromatic compound is dihalogenated aromatic compound 100
〜99.5 mol% and has 3 or more halogen atoms
0 to 0.5 mol% of the polyhalogenated aromatic compound
When the temperature of the reaction solution is raised from a temperature of 220 ° C. or lower to a temperature of 260 ° C. or higher, an average of 0.1 to 0.3 mol per mol of S in the sulfur source is present in the presence of water and an alkali metal carboxylate. 5 ° C. / min with the following heating rate have reaction of a line, the end of the reaction
The remaining amount of the polyhalogenated aromatic compound after
A method for producing polyarylene sulfide, which is not more than 2.5 mol% of the amount . 2. The method according to claim 1, wherein the polyarylene sulfide has a melt flow rate of 500 or less.