JP2000290375A - Preparation of polyarylene sulfide - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a process for preparing a polyarylene sulfide, without need for prepolymerization and control by a complicated temperature pattern, and also without adhesion of the polyarylene sulfide to reactor inner wall and stirring blades. SOLUTION: In a process for preparing a polyarylene sulfide by polycondensing a sulfur source and an aromatic dihalogen compound in an organic polar solvent in the presence of a phase separation agent, stirring blades are used, which have wide upper blades 1 provided with downward fins 2 at the both ends and wide lower blades 3 provided with sweepback blades 4 at the both ends and in which a rotating axis 5 passes through the center line of the upper blades and that of the lower blades, and the upper and lower blades are arranged crosswise.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a polyarylene sulfide, and more particularly, to a method for producing a polyarylene sulfide capable of preventing a polymer from forming a large lump and preventing the polymer from adhering to an inner wall of a reaction vessel. About the method. Since the polyarylene sulfide produced by the method of the present invention has a uniform particle size,
The transfer of the slurry after the polymerization reaction becomes extremely easy, and the productivity can be improved.

[0002]

2. Description of the Related Art Polyarylene sulfide (hereinafter referred to as PA)
S), and particularly, polyphenylene sulfide (hereinafter sometimes referred to as PPS) is excellent in mechanical strength, heat resistance, flame retardancy, solvent resistance, etc., and has good electrical characteristics and high rigidity. It is widely known as engineering plastics, and is widely used as a material for automobile parts, electronic / electric equipment parts, and mechanical parts. Conventionally, N-methyl-2
A method of reacting a dihalogen aromatic compound such as p-dichlorobenzene with a sodium salt such as sodium sulfide in an aprotic organic solvent such as pyrrolidone (hereinafter sometimes referred to as NMP) has been generally used. .
However, in this method, sodium halide is by-produced, and the sodium halide is insoluble in a solvent such as NMP and is taken into the PAS. After polymerization, even if the PAS is washed with a large amount of water, The sodium halide in the PAS could not be sufficiently removed.

[0003] Therefore, it has been noted that polymerization is carried out using a lithium salt instead of a sodium salt, and various improvements have been made in the production of PAS using such a lithium salt. For example, by controlling the lithium concentration at the time of polymerization and maintaining the polymer in a droplet dispersed state, a relatively high-molecular-weight PAS can be easily and smoothly produced (JP-A-7-278304). A method of easily and smoothly producing a PAS having a relatively high molecular weight by performing a prepolymerization before the main polymerization to improve the dispersibility of the polymer (Japanese Patent Laid-Open No. 7-28)
No. 6042) has been proposed, but all of these production methods require preliminary polymerization, so that the production steps are complicated. Also, a method for controlling the particle size of PAS by controlling the temperature pattern during polymerization using lithium chloride as a phase separator (Japanese Patent Laid-Open No. 3-19)
No. 5,734), and a production method in which water is used as a phase separating agent to prevent aggregation of PAS by a polymerization temperature pattern (JP-A-63-46228, JP-A-1-299825) has been proposed. These production methods required prepolymerization, and the temperature pattern during polymerization was complicated. Furthermore, a method of controlling the particle size of PAS by using a lattice blade having a special shape (Japanese Patent Laid-Open No. 4-11 / 1990)
No. 4036) has been proposed, but the range of the stirring power is narrow and not sufficient.

[0004]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above problems, and does not require prepolymerization or complicated temperature pattern control when producing PAS.
An object of the present invention is to provide a method for producing polyarylene sulfide, which can prevent PAS from adhering to the inner wall of a reaction vessel or a stirring blade.

[0005]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, by setting the shape of the stirring blade used for the production of PAS to a specific one,
It has been found that the above problem can be effectively achieved. The present invention has been completed based on such findings. That is, the present invention provides a method for producing a polyarylene sulfide by polycondensing a sulfur source and a dihalogen aromatic compound in the presence of a phase separating agent in an organic polar solvent, wherein both ends are provided with downward fins. A wide upper wing, and a wide lower wing provided with retreating wings at both ends, a rotation axis passing through the center line of the upper wing and the center line of the lower wing, and the upper wing and the lower wing An object of the present invention is to provide a method for producing polyarylene sulfide, characterized by using a stirring blade arranged so as to cross with a blade.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The sulfur source used in the production method of the present invention includes alkali metal sulfide, alkali metal hydrosulfide, hydrogen sulfide and the like. Specific examples of the alkali metal sulfide include lithium sulfide, sodium sulfide, potassium sulfide, rubidium sulfide, and cesium sulfide. Among these, lithium sulfide and sodium sulfide are preferable, and lithium sulfide is particularly preferable. These may be used alone or in combination of two or more. Further, as the alkali metal sulfide, those obtained by a reaction between an alkali metal hydrosulfide and a base may be used. Alternatively, an alkali metal hydrosulfide and a base can be used together with the alkali metal sulfide. Further, hydrogen sulfide and a base can be used together as a sulfur source, and hydrogen sulfide and a base can be used together with an alkali metal sulfide and / or an alkali metal hydrosulfide.
Examples of the alkali metal hydrosulfide include lithium hydrosulfide, sodium hydrosulfide, rubidium hydrosulfide, potassium hydrosulfide, and cesium hydrosulfide. Of these, lithium bisulfide and sodium bisulfide are preferred, and lithium bisulfide is particularly preferred. These may be used alone or in combination of two or more. As the base, those capable of converting the alkali metal hydrosulfide to the alkali metal sulfide, those capable of converting the hydrogen sulfide to the alkali metal hydrosulfide, or the alkali metal hydrosulfide or the hydrogen sulfide are described below. In addition to being able to efficiently neutralize or accept hydrogen halide that can be generated by condensation with a dihalogen aromatic compound, any acid acceptor that does not inhibit the object of the present invention can be an inorganic compound or an organic compound. Although various bases can be used, alkali metal hydroxides and the like are usually preferably used. Specific examples of the alkali metal hydroxide include lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, and cesium hydroxide. Of these, lithium hydroxide and sodium hydroxide are preferred, and lithium hydroxide is particularly preferred. Also,
As the salt of the organic compound, a metal salt of ω-hydroxycarboxylic acid, a metal salt of aminocarboxylic acid and the like can be suitably used. These bases may be used alone or in combination of two or more. In addition, the use ratio of the base is usually about 0.80 to 1.2 mol per 1 mol of the total hydrogen atoms of the alkali metal hydrosulfide and the hydrogen sulfide. Further, the alkali metal sulfide and the alkali metal hydrosulfide are used in an amount of 2.6 to 1 mol per mol.
An industrial product having 9 moles of water of hydration may be used after being previously dehydrated or used as it is.

[0007] Examples of the dihalogen aromatic compound used in the present invention include known compounds used for producing polyarylene sulfide. For example, dihalobenzenes such as p-dihalobenzene and m-dihalobenzene;
-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-2,5-dihalobenzene,
Alkyl-substituted dihalobenzenes such as 1-cyclohexyl-2,5-dihalobenzene or cycloalkyl-substituted dihalobenzenes; 1-phenyl-2,5-dihalobenzene, 1-benzyl-2,5-dihalobenzene, 1-p-
Aryl-substituted dihalobenzenes such as trail-2,5-dihalobenzene; dihalobiphenyls such as 4,4'-dihalobiphenyl; 1,4-dihalonaphthalene, 1,5-
And dihalonaphthalenes such as dihalonaphthalene and 2,6-dihalonaphthalene. The amount of the dihalogen aromatic compound used is usually 0.90 to 1 mol of the sulfur atom in the sulfur source when a later-described branching agent is not used.
To 1.30 mol, preferably 0.95 to 1.20 mol. When a branching agent is used, the total number of moles of the dihalogen aromatic compound and the branching agent is usually 0.90 to 1.30 mol, preferably 0.95 mol, per 1 mol of the sulfur atom in the sulfur source. 11.20 mol. The total mole number of the dihalogen aromatic compound or the dihalogen aromatic compound and the branching agent is
If it is less than 0.90 mol or more than 1.30 mol, the resulting P
The molecular weight of AS may decrease.

The phase separator used in the present invention includes lithium halides such as lithium chloride and lithium fluoride; alkali metal acetates such as lithium acetate and sodium acetate;
Examples include alkali metal sulfonates such as lithium sulfonate and sodium sulfonate, and water. Of these, lithium halide, alkali metal acetate and water are preferred. The amount of the phase separator is not particularly limited as long as the amount of the polymer phase is generated, and is usually 0.05 to 3.0 moles, preferably 1 to 3.0 moles, per mole of the sulfur atom in the sulfur source. Is 0.2 to 2.5 mol. The amount of phase separator used is 0.05
If the amount is less than the above, the effect of adding the phase separation agent is not sufficient, and the reaction rate may be slow, or the resulting PAS may not be sufficiently high in molecular weight or high in purity. On the other hand, if the amount of the phase separating agent exceeds 3.0 mol, the effect corresponding to the amount used is not obtained, and the production cost increases,
Not economic.

In the present invention, together with the phase separating agent,
If necessary, an active hydrogen-containing halogen aromatic compound, 1
A branching agent such as a polyhalogen aromatic compound having three or more halogen atoms therein and a halogen aromatic nitro compound can be appropriately selected and added to the reaction system.
Examples of the active hydrogen-containing halogen aromatic compound include a halogen aromatic compound having a functional group having an active hydrogen such as an amino group, a thiol group, and a hydroxyl group. Dihaloanilines such as aniline, 2,5-dichloroaniline, 2,4-dichloroaniline and 2,3-dichloroaniline; 2,3,4-trichloroaniline, 2,3,5,-
Trihaloanilines such as trichloroaniline, 2,4,6-trichloroaniline and 3,4,5-trichloroaniline; 2,2′-diamino-4,4′-dichlorodiphenyl ether, 2,4′-diamino-2 ′ And dihaloaminodiphenyl ethers such as 1,4-dichlorodiphenyl ether, and compounds in which an amino group is replaced with a thiol group or a hydroxyl group in these compounds. In these active hydrogen-containing halogen-aromatic compounds, a hydrogen atom bonded to a carbon atom forming an aromatic ring is substituted with another inert group, for example, a hydrocarbon group such as an alkyl group. Halogen aromatic compounds can also be used. Of these various active hydrogen-containing halogen aromatic compounds, preferred are active hydrogen-containing dihalogen aromatic compounds, and particularly preferred is dichloroaniline.

The polyhalogen aromatic compound having three or more halogen atoms in one molecule includes, for example, 1,
Examples include 2,4-trichlorobenzene, 1,3,5-trichlorobenzene, 1,4,6-trichloronaphthalene and the like. The halogen aromatic nitro compounds include, for example, monohalonitrobenzenes such as 2,4-dinitrochlorobenzene; dihalonitrobenzenes such as 2,5-dichloronitrobenzene; dinitronitrobenzenes such as 2-nitro-4,4'-dichlorodiphenylether. Halonitrodiphenyl ethers; dihalonitrodiphenylsulfones such as 3,3'-dinitro-4,4'-dichlorodiphenylsulfone; monohalonitropyridines such as 2-chloro-3,5-dinitropyridine; 2,5 And dihalonitropyridines such as -dichloro-3-nitropyridine and various dihalonitronaphthalenes. By using these active hydrogen-containing halogen-aromatic compounds, polyhalogen-aromatic compounds and halogen-aromatic nitro compounds, it is possible to increase the degree of branching of the resulting polymer, further increase the molecular weight, and improve the melt flowability. The properties of the polymer formed by the method of the present invention can be further improved, for example, by producing a gel-forming polymer having a reduced amount. In the method of the present invention, one of these branching agents may be used alone, or two or more thereof may be used in combination. The amount of the branching agent to be used is generally 0.0005 to 0.05 mol, preferably 0.001 to 0.02 mol, per 1 mol of the sulfur atom in the sulfur source.

As the organic polar solvent used in the present invention, aprotic polar organic compounds (for example, amide compounds, lactam compounds, urea compounds, organic sulfur compounds,
Cyclic organic phosphorus compounds) can be suitably used as a single solvent or as a mixed solvent. Among these aprotic polar organic compounds, the amide compound includes, for example, N, N-dimethylformamide, N, N
-Diethylformamide, N, N-dimethylacetamide, N, N-diethylacetamide, N, N-dipropylacetamide, N, N-dimethylbenzoic acid amide.

Examples of the lactam compound include caprolactam, N-methylcaprolactam, N-
N-alkylcaprolactams such as ethylcaprolactam, N-isopropylcaprolactam, N-isobutylcaprolactam, N-normalpropylcaprolactam, N-normalbutylcaprolactam, N-cyclohexylcaprolactam, N-methyl-2-pyrrolidone (N
MP), N-ethyl-2-pyrrolidone, N-isopropyl-2-pyrrolidone, N-isobutyl-2-pyrrolidone, N-n-propyl-2-pyrrolidone, N-n-butyl-2-pyrrolidone, N-cyclohexyl-2
-Pyrrolidone, N-methyl-3-methyl-2-pyrrolidone, N-ethyl-3-methyl-2-pyrrolidone, N-methyl-3,4,5-trimethyl-2-pyrrolidone, N-
Methyl-2-piperidone, N-ethyl-2-piperidone, N-isopropyl-2-piperidone, N-methyl-
6-methyl-2-piperidone, N-methyl-3-ethyl-2-piperidone and the like can be mentioned.

The urea compound includes, for example,
Tetramethylurea, N, N'-dimethylethyleneurea,
N, N'-dimethylpropylene urea and the like can be mentioned. Further, as the organic sulfur compound, for example, dimethyl sulfoxide, diethyl sulfoxide, diphenyl sulfone, 1-methyl-1-oxosulfolane, 1-ethyl-1-oxosulfolane, 1-phenyl-1-oxosulfolane, and the like, Examples of the cyclic organic phosphorus compound include 1-methyl-1-oxophosphorane, 1-n-propyl-1-oxophosphorane, 1-phenyl-1-oxophosphorane, and the like. These various aprotic polar organic compounds, each alone or by mixing two or more,
Furthermore, it can be used as an organic polar solvent by mixing with other solvent components that do not interfere with the object of the present invention. Among the above-mentioned various aprotic organic solvents, preferred are N-alkylcaprolactam and N-alkylpyrrolidone, and particularly preferred is N-methyl-2-pyrrolidone. The amount of the organic polar solvent to be used is generally 1 to 30 mol, preferably 3 to 15 mol, per 1 mol of the sulfur atom in the sulfur source. If the amount of the organic polar solvent is less than 1 mol, the reaction may not proceed sufficiently.
On the other hand, if the amount used exceeds 20 mol, the volumetric efficiency may deteriorate, and the productivity may decrease.

According to the production method of the present invention, a sulfur source and a dihalogen aromatic compound are subjected to polycondensation in an organic polar solvent in the presence of a phase-separating agent using a stirring blade having a specific shape.
This is a method for producing polyarylene sulfide, and prepolymerization is not particularly required. The polymerization temperature may be any temperature at which the polymer phase can be phase-separated, and specifically, 235 to 280.
° C, preferably from 240 to 270 ° C. The PAS produced by the method of the present invention has a particle size of 1000 μm or less and an intrinsic viscosity η _ihr of 0.1 to ∞. The stirring blade used in the present invention has a wide upper wing provided with downward fins at both ends and a wide lower wing provided with retreating wings at both ends, and the rotation axis is defined by the center line of the upper wing. The stirring blade is not particularly limited as long as it is a stirring blade that passes through the center line of the lower blade and is arranged so that the upper blade and the lower blade cross each other. As such a stirring blade, for example, a stirring blade having a shape shown in FIG. FIG. 2 is a view of the stirring blade shown in FIG. In FIG. 1, reference numeral 1 denotes an upper wing provided with fins 2 at both ends, and reference numeral 3 denotes a lower wing provided with a retreat wing 4 at both ends. As shown in FIG. 2, the retreating wing 4 rotates the stirring blade with respect to the lower wing 3 (indicated by an arrow in FIGS. 1 and 2).
Has an angle in the opposite direction. In FIG. 1, reference numeral 5 denotes a rotating shaft, 6 denotes an autoclave, and 7 denotes a baffle. A specific example of such a stirring blade is a full zone blade manufactured by Shinko Pantech Co., Ltd.

The stirring blade is rotated by an appropriate stirring power.
To prevent polymer adhesion more effectively
be able to. The stirring power is calculated as follows.
You. That is, the specific gravity and viscosity of the reaction solution
Therefore, it is necessary to estimate the appropriate stirring power of the stirring blade.
Is difficult. Therefore, the specific gravity of the reaction solution is 1 kg / lit.
And a viscosity of 1 cp.
Calculated as stirring power. Stirring per unit volume based on water
Power Pv is 0.025-0.3 kW / m^ThreeAnd can be poly
It is effective for preventing adhesion of the mer. The stirring power is 0.3 kW /
m^ThreeIf it exceeds, the polymer phase may be united and become a lump
Yes, and the stirring power is 0.025 kW / m ^ThreeIs less than
And polymer phase may accumulate at the bottom of the reactor and form a lump
is there.

[0016]

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. Intrinsic viscosity η _ihr [deciliter / g]
Is obtained by dissolving 0.04 g ± 0.001 g of a sample in 10 ml of α-chloronaphthalene within 15 minutes at 235 ° C., and obtaining the viscosity obtained in a thermostat at 206 ° C. and the α-chloro The relative viscosity with respect to the viscosity of naphthalene was measured and calculated by the following equation: η _ihr = ln (relative viscosity) / polymer concentration. Example 1 A full zone blade manufactured by Shinko Pantech Co., Ltd. having a shape shown in FIGS. 1 and 2 was used as a stirring blade. This full zone wing has an upper wing span of 110 mm and a lower wing span of 120 mm.
mm, theta ₁ is 45 degrees, theta ₂ is of 45 degrees. In a 10-liter autoclave equipped with the full zone wings and two baffles diagonally, 10 mol of lithium sulfide (459.4 g), paradichlorobenzene (P-DC
B) 10 mol (1470.1 g) 1 mol of lithium hydroxide monohydrate (41.96 g), 4 mol of water (72.1 g) and NM
4.3 liters of P (N-methyl-2-pyrrolidone) were charged. The temperature was raised to 260 ° C. under the conditions of a rotation speed of 125 rpm (water-based stirring power per unit volume Pv = 0.2 kW / m ³ ), and polymerization was performed at 260 ° C. for 3 hours. Then 100
After cooling to below ℃, the reactor was opened. The obtained polymer was granular having a diameter of 1000 μm or less. Also,
After a part of the polymer was washed with a large amount of hot water and dried, the intrinsic viscosity η _inh was measured and found to be 0.22 deciliter / g.

Example 2 The stirring speed of the full zone blade was set to 100 rpm (Pv = 0.1).
kW / m ³ ), except that it was changed to kW / m ³ ). The obtained polymer was granular having a diameter of 1000 μm or less, and the intrinsic viscosity η _inh was 0.23 deciliter / g. Example 3 The stirring speed of the full zone blade was set to 50 rpm (Pv = 0.05).
kW / m ³ ), except that it was changed to kW / m ³ ). The obtained polymer was granular having a diameter of 1000 μm or less, and the intrinsic viscosity η _inh was 0.23 deciliter / g. Comparative Example 1 Except that the stirring blade was changed to a Max Blend blade manufactured by Sumitomo Heavy Industries, Ltd., the same procedure as in Example 1 was carried out. As a result, the polymer was agglomerated on the reactor wall. The intrinsic viscosity η _inh is
It was 0.23 deciliter / g. Comparative Example 2 A stirring blade and a baffle were prepared in the same manner as in Example 1 except that the stirring blade was changed to a 45 ° inclined paddle blade and the stirring rotation speed was set to 126 rpm (Pv = 0.2 kW / m ³ ). The polymer condensed around and around the bottom of the reactor. The intrinsic viscosity η _{in h} was 0.22 deciliter / g. Comparative Example 3 The stirring blade was changed to a Furdora blade manufactured by Shinko Pantech Co., Ltd., and the stirring rotation speed was set to 265 rpm (Pv = 0.2 kW /
m ³ ), except that it was changed to m ³ ).
The polymer was condensed around the stirring blade, around the baffle and at the bottom of the reactor. The intrinsic viscosity η _inh was 0.22 deciliter / g.

Example 4 In a 10 liter autoclave equipped with full zone blades and two baffles diagonally, 8.14 mol (1369 g) of sodium sulfide pentahydrate (Na ₂ S.5H ₂ O) was added.
8.14 mol (345 g) with lithium chloride (LiCl)
And 4.1 liters of NMP, and stirring speed 125r
Stirred at pm. The temperature was raised to 195 ° C. under a stream of N ₂ to obtain 1.8 liter of distillate. At that time, 6.88 mol% of hydrogen sulfide (H ₂ S) gas with respect to Na ₂ S was distilled off from the autoclave. The autoclave was cooled to 100 ° C., and 6.54 mol (1108 g) of paradichlorobenzene (P-DCB) and dichloronitrobenzene (DCN
B) 0.046 mol (8.74 g) and 1.5 l of NMP were added. Stirring speed 125 rpm (Pv = 0.2 kW /
m ³ ) The temperature was raised to 260 ° C., and polymerization was performed for 3 hours. Then
After cooling to below 100 ° C., the reactor was opened. The obtained polymer was granular having a diameter of 1000 μm or less.
A part of this polymer was washed with a large amount of hot water and dried, and then the intrinsic viscosity η _inh was measured. However, since the produced polymer had an infinite molecular weight and was insoluble in the measurement solvent, the intrinsic viscosity η _inh was measured. _Inh could not be measured. Comparative Example 4 Except for using the Max Blend blade in Example 4,
When the same procedure as in Example 4 was carried out, stirring became impossible 1.5 hours after the temperature reached 260 ° C. When the autoclave was opened, it was confirmed that the polymer was aggregated and attached around the stirring blade. Table 1 summarizes the above results.

[0019]

[Table 1]

[0020]

According to the production method of the present invention, the polyarylene sulfide can be converted without the need for prepolymerization or complicated temperature pattern control, and without the polyarylene sulfide adhering to the inner wall of the reaction vessel or the stirring blade. Can be manufactured.

[Brief description of the drawings]

FIG. 1 is a view showing the appearance of a stirring blade used in the present invention.

FIG. 2 is a view of the stirring blade shown in FIG. 1 as viewed from a direction A.

[Explanation of symbols]

 1: Upper wing 2: Fin 3: Lower wing 4: Swept wing 5: Rotation axis

Claims (3)

[Claims] 1. A method for producing polyarylene sulfide by polycondensing a sulfur source and a dihalogen aromatic compound in an organic polar solvent in the presence of a phase separating agent. An upper wing, and a wide lower wing provided with retreat wings at both ends, a rotation axis passing through a center line of the upper wing and a center line of the lower wing, and the upper wing and the lower wing Using a stirring blade arranged so as to intersect with the polyarylene sulfide. 2. The stirring power of the stirring blade is 0.025 to 0.3 k.
Polyarylene sulfide production method of claim 1, wherein a W / m ^3. 3. The method for producing polyarylene sulfide according to claim 1, wherein the phase separation agent is at least one selected from lithium halide, acetate and water.