KR100222316B1 - Process for the preparation of polyarylene sulfide and an apparatus for the preparation thereof - Google Patents

Abstract

The present invention relates to a method and apparatus for producing a high molecular weight polyarylene sulfide by reacting an alkali metal sulfide and a dihaloaromatic compound in an organic amide solvent, wherein the gaseous part of the reactor is cooled to a part of the gas phase of the reactor. Is condensed and the condensed liquid is refluxed to the liquid phase of the reactor, characterized in that a high molecular weight is obtained by polymerization with a polyhaloaromatic compound of 0.005 to 1.5 mol% based on alkali metal sulfide.

Description

Method for producing polyarylene sulfide and apparatus therefor

1 is a schematic view of a reactor with an external cooling coil.

2 is a schematic view of a reactor with an internal cooling coil.

3 is a schematic representation of a reactor with a coolant jacket.

4 is a schematic view of a reactor unit with a liquid spray.

5 is a schematic diagram of a reactor with a gas injection unit.

* Explanation of symbols for main parts of the drawings

1 reactor 2 stirring device

3: heat medium jacket 4,5,8,9,12,13,42,43,52: conduit

10: heat insulating material 11: external cooling coil

21: internal cooling coil 31: cooling jacket

41,51: Nozzle

[Field of Invention]

The present invention relates to a process for the preparation of polyarylene sulfides, in particular high molecular weight polyarylene sulfides and devices thereof.

[Old technology]

The basic production method of polyarylene sulfide (hereinafter referred to as "PAS") is known to react a dihaloaromatic compound with an alkali metal sulfide in an organic amide solvent (Japanese Patent Publication No. 3368/1970). Since PAS prepared by this method has a low molecular weight, heat cross linking treatment was performed to obtain a high molecular weight. However, crosslinked PAS is difficult to process into films, sheets, fibers and the like.

Recently high molecular weight PAS has been produced without thermal crosslinking. Films, sheets, fibers, etc. made from such PAS have excellent mechanical properties. In injection molding such PAS exhibits high flowability at low shear rates during melt processing and because of the bright color of the PAS, the demand for the PAS is increasing for that reason.

Various production methods are known for producing high molecular weight PAS simply by polymerization. In the method described in Japanese Patent Publication No. 12240/1977, alkali metal carboxylates such as sodium acetate and lithium acetate were used as polymerization aids in conventional reaction systems. However, as a result, the manufacturing cost of PAS is high in this method, which makes this method very commercially unsuitable. Separation and recovery of alkali metal carboxylates from the product required many additional facilities, techniques and costs to discharge them without pollution, making this method more disadvantageous.

Japanese Patent Laid-Open No. 7332/1986 describes a method for producing high molecular weight PAS, which is characterized in that the reaction is carried out in two steps and water is injected in the second step. That is, in the first step, the reaction is carried out at 180-235 ° C. in the presence of 0.5-2.4 moles of water per mole of alkali metal sulfide to form PAS with a conversion rate of 50-98 mole% of the dihaloaromatic compound.

In the second step, water is injected and the reaction is carried out at 245-290 ° C. in the presence of 2.5-7.0 moles of water.

Likewise, many other methods of preparing high molecular weight PAS by intentionally present water are also known. In the method described in Japanese Patent Laid-Open No. 39926/1988, the reaction is carried out in a first step at a temperature of 235 to 280 ° C at a conversion rate of 70 to 98 mol% in the presence of 0.5 to 5 mol of water per kg of solvent. In the second step, water is injected and the reaction is carried out at a temperature of 240-290 ° C. in the presence of 6-15 moles of water.

This method is characterized in that the reaction temperature is high in the first step, the water content is low, and a large amount of water is injected in the first step as compared with the Japanese Patent Laid-Open No. 7332/1986 to cause separation in the liquid-liquid two layers in the second step.

It is also known how the reaction further occurs after separation into the two liquid-liquid layers. That is, in the method described in Japanese Patent Application Laid-Open No. 285922/1987, the reaction occurs at a conversion rate of at least 80 mol% at a temperature of 180 to 235 ° C in the presence of 0.5 to 2.4 mol of water per mol of the alkali metal sulfide in the first step. In the second step water is injected and the reaction is carried out at a temperature of 245-290 ° C. in the presence of 2.5-7.0 moles and then stirring is stopped to cause separation into two layers. In the third step, the lower layer (concentrated polymer solution layer) is reacted at a temperature of 245 ~ 350 ℃.

In the above-mentioned method, water is injected in the middle of the reaction and the water content is changed in the middle of the reaction to produce a high molecular weight PAS. There are only three choices to do this: lower the temperature first and then inject water to reduce the pressure to normal pressure; Changing the reactor between the first and second stages; Or water at a high pressure and into a reactor at high pressure. However, this operation has practical disadvantages in terms of equipment, economy and operation. In addition, sodium sulfide is usually used at a concentration of 1 mole per 0.4 to 0.5 kg of solvent (eg N-methylpyrrolidone). In the second step, if more than 2.5 moles of water per mole of sodium sulfide are present at more than 245 ° C, the pressure is increased by more than 20 kg / cm 2 G.

Therefore, the reactor must withstand a pressure of 30 kg / cm 2 G or more. It is therefore not possible to use equipment built for the previous method in which no water is injected in the middle of the reaction. Since pressure-resistant equipment is relatively expensive, the method used at low pressure as before is preferable. In addition, operation under low pressure is desirable as far as possible in terms of safety.

In addition, high molar ratios of alkali metal sulfides to dihaloaromatic compounds, such as 0.980 to 1.01, are basically required to produce high molecular weight PAS only by polymerization. When the polymerization temperature rises above 230 ° C., the reaction system having a high ratio of alkali metal sulfide to dihaloaromatic compound becomes unstable, and high molecular weight PAS is not formed or PAS once depolymerized, thereby causing low molecular weight polymer and a significant amount of thio Phenolic may be formed.

It is known to use polyhaloaromatic compounds with at least three halogen substituents in the molecule to produce high molecular weight PAS by simply polymerization. In the method described in Japanese Patent Publication No. 8719/1979, a polyhaloaromatic compound and lithium carbonate or lithium chloride are injected into a conventional reaction system. This method is very disadvantageous commercially because expensive lithium carbonate or lithium chloride has to be used at about the same molar ratio as the alkali metal sulfide, increasing the manufacturing cost of PAS. In addition, many additional facilities, techniques, and costs are required to separate and recover lithium carbonate and lithium chloride from the product without pollution, making this method more disadvantageous.

In the method described in Japanese Patent Publication No. 334/1982, 1.2 to 2.4 moles of water (including hydrated water of alkali metal sulfide) or 1.0 to 2.4 moles of water and sodium carbonate per mole of polyhaloaromatic compound, alkali metal sulfide It is injected into this conventional reaction system. According to the embodiment, when sodium carbonate is not added, high molecular weight PAS is not obtained sufficiently unless at least 1.5 moles of water are present. If the water content in the system is so high, the pressure of the reactor becomes high during the reaction, which requires a reactor that withstands high pressure, which is expensive.

On the other hand, when sodium carbonate is added, additional facilities and techniques are needed to separate, recover and discharge sodium carbonate from the product without pollution, increasing costs.

[Summary of invention]

It is an object of the present invention to eliminate the need for expensive polymerization aids, such as alkali metal carboxylates and lithium chloride, and to provide a high molecular weight in which a polymerization reaction can be carried out at a constant and relatively low water content in a low pressure reactor without the need for additional equipment such as a pressure injection device. It is to provide an economical and convenient method for producing polyarylene sulfide.

It is another object of the present invention to provide an apparatus for producing high molecular weight polyarylene sulfide.

The present inventors have studied the polymerization mechanism in detail to solve the above problems in the preparation of high molecular weight polyarylene sulfide and found that the problem can be solved by cooling the gaseous part of the reactor and the polyarylene sulfide formed thereby Depolymerization of can also be prevented.

The present invention relates to a method for producing a polyarylene sulfide by reacting an alkali metal sulfide and a dihaloaromatic compound in an organic amide solvent, wherein the gaseous portion of the reactor is cooled to condense a part of the gaseous phase of the reactor, and the condensed liquid is It is characterized by reflux to the upper liquid phase. Preferably, 0.005-1.5 mol% of polyhaloaromatic compounds are copolymerized based on alkali metal sulfide to obtain higher molecular weight polyarylene sulfide.

The present invention also provides an apparatus for producing a polyarylene sulfide by reacting an alkali metal sulfide and a dihaloaromatic compound in an organic amide solvent, the apparatus for cooling a gas phase portion of a reactor for condensing a part of the gas phase of the reactor. And a device for recovering the condensed liquid to the upper liquid phase of the reactor.

Detailed description of the invention

The condensed and refluxed liquid has a higher water content than the vapor phase bulk due to the difference in vapor pressure between the water and the amide solvent. This reflux with higher water content creates a layer with more water content in the upper part of the reaction mixture. As a result, larger amounts of remaining alkali metal sulfides (eg Na ₂ S), alkali metal halides (eg NaCl) and oligomers are included in this layer.

In the conventional method, the resulting polyarylene sulfide, starting materials such as Na ₂ S and by-products are uniformly mixed together at a temperature of 230 ° C. or higher. Under such conditions, high molecular weight polyarylene sulfides are not formed and once formed polyarylene sulfides are depolymerized to form low molecular weight polymers and significant amounts of thiophenols as by-products.

In the present invention, there are no such undesirable phenomena, the factors which disturb the reaction are very effectively excluded and high molecular weight polyarylene sulfide actively cools the gas phase portion of the reactor and refluxs a large amount of water to the upper portion of the gas phase. It can be obtained by recovering water.

However, the present invention should not be limited by the effect obtained only by the above phenomenon, and the various effects caused by cooling the gas phase portion produce high molecular weight polyarylene sulfide.

In the present invention, unlike the conventional method, it is unnecessary to inject water in the middle of the reaction. However, some of the advantages of the present invention will be lost due to the introduction of water. It is therefore desirable that the total water content in the polymerization system be constant during the reaction.

In general, the polymerization of polyarylene is carried out at a temperature of 180 ~ 350 ℃ and the reactor must be heated. Therefore, it is common to wrap the reactor or the entire reactor with a heat insulating material for thermoeconomic reasons. On the other hand, the gas phase portion of the reactor is rather cooled in the present invention. This, of course, is disadvantageous in terms of thermal economy compared to conventional methods, but the advantages obtained also compensate for the disadvantages. The cooling device of the gas phase portion of the reactor may be external cooling or internal cooling, preferably (a) an external cooling coil wound on the upper outer wall of the reactor, (b) an internal cooling coil mounted on the upper inner portion of the reactor, (c A coolant jacket mounted on the upper outer wall of the reactor, (d) a device for injecting or blowing liquid or gas directly into the upper outer wall of the reactor, or (e) a reflux condenser, for example mounted on the top of the reactor. The chiller need not extend to the entire vapor phase of the reactor. If the cooling effect reaches the liquid part, it is worse in terms of thermal economy. Therefore, it is desirable to cool only the upper gaseous portion, which is sufficient. The ambient temperature is relatively low (eg normal temperature), and suitable cooling can be done by removing the insulating material from the upper portion of the conventional reactor.

The water / amide solvent mixture condensed on the wall of the reactor or on the wall of the internal cooler flows down the wall to reach the upper part of the liquid phase of the reactor, or is collected in some way to the upper part of the liquid phase of the reactor.

On the other hand, the temperature of the liquid bulk is kept constant at a predetermined value or controlled according to a predetermined temperature profile. When the temperature becomes constant, the reaction preferably takes place for 0.1 to 20 hours at a temperature of 230 to 275 ° C, more preferably for 1 to 6 hours at a temperature of 240 to 265 ° C. It is preferable to apply the reaction temperature profile in at least two steps to obtain a higher molecular weight polyarylene sulfide. The first step is preferably carried out at a temperature of 195-240 ° C.

If the temperature is low, the reaction rate is too slow to be practical. If the temperature exceeds 240 ° C., the reaction rate is too fast to obtain a polyarylene sulfide of sufficiently high molecular weight, and the rate of side reactions also increases markedly. Preferably the ratio of the remaining dihaloaromatic compound to the dihaloaromatic compound injected into the polymerization system is 1-40 mol% and the molecular weight reaches 3,000-20,000, and more preferably the ratio is 2-15 mol%. The first stage ends when the molecular weight reaches 5,000 to 15,000. If the ratio exceeds 40 mole%, side reactions such as depolymerization occur in subsequent second steps. If the ratio is 1 mol% or less, it is difficult to finally obtain a high molecular weight polyarylene sulfide. Then the temperature is increased and in the first step the reaction is preferably carried out for 1 to 10 hours at a temperature of 240 ~ 270 ℃. If the temperature is lower, a sufficiently high molecular weight polyarylene sulfide is not obtained, and if the temperature exceeds 270 ° C, side reactions such as depolymerization occur, making it difficult to stably produce a high molecular weight product.

In practice, the content of water in the alkali metal sulfide in the amide solvent is adjusted to a predetermined value in the inert gas atmosphere by dehydration or addition of water if necessary. The content of water is preferably 0.5 to 2.5 moles per mole of alkali metal sulfide. If the amount of water is less than 0.5 moles, the reaction rate is too fast and unwanted reactions such as side reactions can occur. If the amount of water exceeds 2.5 moles, the reaction rate is too slow, and a large amount of by-products such as phenol appear in the filtrate after the reaction and have a low degree of polymerization. The dihaloaromatic compound may be injected at the beginning or in the middle of the water content control, and the amount thereof is preferably 0.9 to 1.1 moles per mole of alkali metal sulfide to obtain a high molecular weight polyarylene sulfide.

In the case of a one-step reaction at a constant temperature, the cooling of the gas phase portion should occur below 250 ° C. at the middle of the temperature rise at the latest, but it is preferable to start at the beginning of the reaction. In the case of several stages of reaction, it is preferred that the cooling begin after the first stage of the reaction and in the middle of the temperature rise, but more preferably at the beginning of the reaction. The pressure in the reactor is usually the most appropriate means to measure the degree of cooling effect. The absolute value of the pressure depends on the characteristics of the reactor, the stirring conditions, the water content in the reaction system, and the molar ratio of the dihaloaromatic compound to the alkali metal sulfide. However, the reduced reaction pressure compared to that under the same reaction conditions except that there is no cooling means that the reflux amount is increased and the temperature at the gas-liquid interface of the reaction solution is lowered. The relative decrease in pressure is believed to indicate the degree of separation between the bed with the higher water content and the rest of the bed. Therefore, cooling should be done so that the internal pressure of the reactor is lower than the internal pressure in the case where no cooling is performed. Those skilled in the art will be able to measure the degree of cooling according to the equipment and operating conditions used.

The polyarylene sulfides thus prepared can be separated from the by-product and dried in known replenishment processes.

The invention is explained in more detail with reference to the accompanying drawings. 1 shows a reactor unit having a cooling coil wound inside the reactor top. Reactants are injected into reactor 1 through conduit 8 to form a stirred liquid phase with agitation device 2.

The liquid part of the reactor 1 is wrapped in a heat medium jacket 3 through which the heat medium flows through the conduit 4 and out through the conduit 5. In the liquid phase of the reactor, the internal heating coil 6 is insulated, where the heat medium flows in and out. In the upper part of the reactor nitrogen is injected for pressurization through the conduit 8 and again for decompression through the conduit 8. After sodium sulfide is injected, thermal dehydration is performed to suction through the conduit (8). The slurry comprising polyarylene formed after completion of the polymerization is discharged through the conduit 9. On the upper outer wall of the reactor, an external cooling coil 11 is wound where coolant, for example water at 20-90 ° C., is injected through the conduit 13 under flow control by means of a control valve (not shown) and the conduit 12 Is discharged through. In this way, the gas phase portion (ie, the top) of the reactor is cooled and the gas phase portion is condensed, flowing down the walls of the reactor and refluxed to the liquid phase.

The former reactor is wrapped with heat insulator 10. 2 shows another specific embodiment in which the internal cooling coil 21 is installed in the upper inner portion of the reactor 1. 2 shows the same parts as in FIG. 1 and the same in other drawings.

The liquid condensed on the surface of the internal cooling coil 21 flows down the walls of the cooling coil and then the reactor and reaches the liquid phase. Alternatively, a trough may be installed to receive the falling water condensed on the surface of the cooling coil 21 and inject it into the liquid phase. In another specific embodiment shown in FIG. 3, a cooling jacket 31 is mounted on the upper outer wall of the reactor 1. In another embodiment, shown in FIG. 4, water is supplied through conduit 42 and sprayed directly through nozzle 41 to the upper outer wall of reactor 1. The sprayed water slowly flows down through the conduit 43 and flows into the porous support for the insulator 44, such as, for example, a stainless steel sponge layer. In another specific embodiment shown in FIG. 5, there is no thermal insulation material on top of the reactor 1 and the walls of the reactor are exposed. Pressurized air is supplied through conduit 52 and blown through nozzle 51 to the top outer wall of the reactor.

The slurry comprising polyphenylenesulfide prepared in the apparatus according to the invention is discharged through the conduit 9 and separated from the by-products and dried in a conventional step.

Amide solvents used in the present invention are known for the polymerization of polyphenylenesulfide and examples thereof include N-methylpyrrolidone (hereinafter referred to as "NMP"), N, N-dimethylformamide, N, N-dimethyl Acetamide, N-methylcaprolactam and the like and mixtures of NMP and the above are preferred. All of these materials have a lower vapor pressure than water.

Alkali metal sulfides used in the present invention are also known and examples are lithium sulfide, sodium sulfide, potassium sulfide, rubidium sulfide and mixtures thereof.

They may be hydrated and may be in the form of an aqueous solution. Alternatively, hydrogen sulfide or its hydrate can be converted into the corresponding sulfide with each corresponding hydroxide, and less expensive sodium sulfide is preferred. The dihaloaromatic compound used in the present invention can be selected from those described in Japanese Patent Publication No. 3368/1970, with p-dichlorobenzene being preferred. M-dichlorobenzene, o-dichlorobenzene, p, p'-dichlorodiphenylether, m, p'-dichlorodiphenylether, m, m'-dichlorodiphenylether, p, p'-dichlorodiphenylsulfone Co, such as m, p'-dichlorodiphenylsulfone, m, m'-dichlorodiphenylsulfone, p, p'-dichlorobiphenyl, m, p'-dichlorobiphenyl and m, m'-dichlorobiphenyl It can be used in small amounts (up to 20 mol%) of m-dihalobenzene, o-dihalobenzene, dihalogenated diphenyl ether, diphenylsulfone and biphenyl to prepare the polymer. Small amounts of additives such as monohalogenated compounds may be used as end group terminators or modifiers.

[Preparation of high molecular weight polyarylene sulfide into polyhaloaromatic compound]

High molecular weight polyarylene sulfides are prepared by adding polyhaloaromatic compounds such as comonomers in the reaction system of the present invention.

In this specific example, the total water content of the reaction system is preferably less than 1.7 moles per mole of alkali metal sulfide, more preferably 0.8 to 1.2 moles.

If the water content exceeds 1.7 moles, side reactions occur remarkably. If the water content of the reaction system increases, the amount of by-products such as phenol increases in the reaction product and the degree of polymerization also increases. If the water content is less than 0.8 mol, the reaction rate is too fast to obtain the desired high molecular weight.

The polyhaloaromatic compound is used in an amount of 0.005 to 1.5 mol%, preferably 0.02 to 0.75 mol%, based on the alkali metal sulfide. If the amount is less than 0.005 mol%, the effect of the addition of the polyaromatic compound cannot be obtained. If the amount exceeds 1.5 mol%, the viscosity of the polyarylene sulfide in the molten state becomes high, and thus, a gel-like substance appears during molding, or the moldability deteriorates.

The polyhaloaromatic compound may be added together with the dihaloaromatic compound in the reaction system or at any time during the intermediate stage of the reaction.

The polyhaloaromatic compound used in the present invention has at least three halogen substituents in the molecule, for example 1,2,3-trichlorobenzene, 1,2,4-trichlorobenzene, 1,3,5- Trichlorobenzene, 1,3-dichloro-5-bromobenzene, 2,4,6-trichlorotoluene, 1,2,3,5-tetrabromobenzene, hexachlorobenzene, 1,3,5-trichloro Rho-2,4,6-trimethylbenzene, 2,2 ', 4,4'-tetrachlorobiphenyl, 2,2', 6,6'-tetrabromo-3,3 ', 5,5'- Tetramethylbiphenyl, 1,2,3,4-tetrachloronaphthalene, 1,2,4-tribromo-6-metalnaphthalene and mixtures thereof, for example 1,2,4-trichlorobenzene and 1,3,5-trichlorobenzene is preferred.

EXAMPLE

The invention is explained in more detail below with reference to the examples.

In Examples and Comparative Examples, the molecular weight is the peak top molecular weight obtained by changing the retention time determined in gel permeation chromatography using 1-chloronaphthalene as the mobile phase at 210 ° C. to the molecular weight based on standard polystyrene corrected by the universal calibration method. . The device used was the SSC-7000 type from Sensu Kagaku.

However, in Examples 9-16 and Comparative Examples 7-11, the weight average molecular weight was used instead of the peak top molecular weight.

Example 1

19.253 kg of flake sodium sulfide (content 60.8 wt.% Na ₂ S) and 45.0 g of N-methyl-2-pyrrolidone (shown below as NMP) in a 150-liter autoclave with an external cooling coil as shown in FIG. Put it. The temperature was raised to 204 ° C while stirring in a nitrogen stream, and 4.442 kg of water was distilled off. The autoclave was then sealed and cooled to 180 ° C. and 21.940 kg p-chlorobenzene (indicated below as p-DCB) and 18.0 kg NMP were added. The temperature was raised after pressurizing to 1 kg / cm <2> G (gauge pressure) using nitrogen at the liquid temperature of 150 degreeC. The coil wound around the upper outside of the autoclave was stirred at a liquid temperature of 220 ° C. for 3 hours while flowing a coolant at 20 ° C. to cool the autoclave. The liquid temperature was then raised and further stirred at liquid temperature of 260 ° C. for 3 hours. The temperature was then lowered and cooling of the upper part of the autoclave was stopped. The maximum pressure during the reaction was 8.71 kg / cm 2 G.

The resulting slurry was filtered, washed continuously with hot water in a conventional manner, and dried at 120 ° C. for 4,5 hours to obtain a white powder product. The molecular weight of polyphenylene sulfide as the obtained product was 42,000, The conversion rate was found to be 98.4%.

Thiophenol was not detected in the reaction product when detected by gas chromatography.

Example 2

As shown in FIG. 4, 513.4 kg of sodium sulfide (Na ₂ S content of 60.3% by weight) and 1190 kg of NMP were added to a 4 m 3 autoclave equipped with a water sprinkler nozzle.

The temperature was raised to 204 degreeC in nitrogen stream, stirring, and 111.3 kg of water was distilled off. The autoclave was then sealed and cooled to 180 ° C. and 583.1 kg p-DCB and 400 kg NMP were added. The pressure was raised to 1 kg / cm 2 G using a nitrogen gas at a liquid temperature of 150 ° C. and then increased. Water was added to the upper part of the autoclave, and the upper part was cooled, and stirred at liquid temperature of 215 degreeC for 5 hours. Then the temperature was raised and stirred for further 4 hours at a liquid temperature of 255 ° C. The temperature was lowered and cooling at the top of the autoclave was also stopped. The maximum pressure during the reaction was 9.2 kg / cm 2 G.

The slurry thus obtained was filtered, washed repeatedly with hot water in a conventional manner, and then dried in a 130 ° C. dryer to obtain a white powder product. The molecular weight of polyphenylene sulfide obtained was 46,500, the conversion was 98.6%, and thiophenol was not detected in the reaction product.

Example 3

As shown in FIG. 5, in a 150 m 3 autoclave equipped with an air injection nozzle, 19.253 kg of sodium flake sulfide (Na ₂ S content of 60.8% by weight) and 45.0 kg of NMP were added.

The temperature was raised to 204 ° C. in a nitrogen stream while stirring, and 4.074 kg of water was distilled off. After that, the autoclave was sealed and cooled to 180 ° C, and 21.940 kg of p-DCB and 18.0 kg of NMP were added thereto. After rising to a liquid temperature of 240 ° C., air was blown through the eight nozzles at the flow rate of 20 l / min to the top of the autoclave from which the thermal insulation was removed. It stirred at the liquid temperature of 250 degreeC for 2 hours. The temperature was lowered and cooling at the top of the autoclave was also stopped. The maximum pressure during the reaction was 8.89 kg / cm 2 G.

The resulting slurry was filtered, washed repeatedly with hot water in a conventional manner, and dried at 120 ° C. for 4,5 hours to obtain a white powder product. The obtained polyphenylene sulfide had a molecular weight of 30,300, a conversion of 98.6%, and no thiophenol was detected in the reaction product.

Comparative Example 1

The polymerization was carried out as in Example 1 except that no coolant was passed through the external cooling coil. The maximum pressure during the reaction was 10.3 kg / cm 2 G. The molecular weight of the obtained polymer was 27,500 and the conversion was 99.0%. Thiophenyl was present in the reaction at a concentration of 200 ppm.

Comparative Example 2

The polymerization was performed as in Example 1 except that the external cooling coil was passed a heating medium at 270 ° C. The maximum pressure during the reaction was 11.2 kg / cm 2 G.

The molecular weight of the obtained polymer was 22,000 and the conversion was 99.1%. The polymer obtained was a slightly brownish white powder and thiophenol was present at 400 ppm in the reaction product.

Comparative Example 3

The same process as in Example 2 was repeated except that water was not cooled by spraying the top of the autoclave. The maximum pressure during the reaction was 10.8 kg / cm 2 G. The resulting polymer had a molecular weight of 23,500 and a conversion of 99.0%. The thiophenol was present at 250 ppm in the reaction product.

Example 4

As shown in FIG. 5, 388.3 kg of sodium sulphate (60.3 wt.% Na ₂ S) and 900 kg of NMP were placed in a 3 L autoclave equipped with an air injection nozzle.

The temperature was raised to 204 ° C. in a nitrogen stream while stirring, and 81.2 g of water was distilled off. Thereafter, the autoclave was sealed and cooled to 180 ° C, and a solution containing 436.6 g of p-DCB and 4.4 g of m-dichlorobenzene dissolved in 240 g of NMP was added thereto. The pressure was raised to 1 kg / cm 2 G using a nitrogen gas at a liquid temperature of 150 ° C. and then increased. Air was blown into the upper part of the autoclave, and the upper part was cooled, and stirred for 5.5 hours at the liquid temperature of 215 degreeC. Then, the temperature was raised and further stirred at the liquid temperature of 250 ° C. for 3 hours. The temperature was then lowered and at the same time cooling of the top of the autoclave was stopped. The maximum pressure during the reaction was 8.18 kg / cm 2 G.

The resulting slurry was filtered, washed repeatedly with hot water in a conventional manner, and then dried in an oven at 120 ° C. for 5 hours to obtain a white powder product. The obtained polyphenylene sulfide had a molecular weight of 37,600, a conversion of 98.8%, and no thiophenol was detected in the reaction product.

[Comparative Example 4]

The same process as in Example 3 was repeated except that no air was blown over the top of the autoclave covered with the thermal insulation material. The maximum pressure during the reaction was 10.8 kg / cm 2. The resulting polymer had a molecular weight of 26,500, a conversion of 98.9% and thiophenol in the reaction product at a concentration of 140 ppm.

Example 5

As shown in FIG. 4, 513.4 kg of sodium sulfide (Na ₂ S content of 60.8 wt%) and 1190 kg of NMP were added to a 4 m 3 autoclave equipped with a water sprinkler nozzle.

The temperature was raised to 204 degreeC in nitrogen stream, stirring, and 111.3 kg of water was distilled off. The autoclave was then sealed and cooled to 180 ° C. and 583.1 kg p-DCB and 400 kg NMP were added. The pressure was raised to 1 kg / cm 2 G using a nitrogen gas at a liquid temperature of 150 ° C. and then increased. After the liquid temperature reached 240 ° C., the upper part of the autoclave was sprayed with water to cool the upper part. Then, the temperature was raised and further stirred at the liquid temperature of 255 ° C. for 2 hours. The temperature was then lowered and at the same time cooling of the top of the autoclave was stopped. The maximum pressure during the reaction was 9.4 kg / cm 2 G.

The slurry thus obtained was filtered, washed repeatedly with hot water in a conventional manner, and then dried in a 130 ° C. dryer to obtain a white powder product. The molecular weight of the obtained polyphenylene sulfide was 31,500, the conversion was 99.1%, and thiophenol was not detected in the reaction product.

[Comparative Example 5]

The same process as in Example 5 was repeated except that cooling was not performed by spraying water on the top of the autoclave. The maximum pressure during the reaction was 11.0 kg / cm 2 G.

The resulting polymer had a molecular weight of 23,800 and a conversion of 99.3%, with thiophenol present in the reaction at a concentration of 220 ppm.

Example 6

The upper part, filled with liquid, was covered with a thermal insulation material and exposed to air and a 4m 3 autoclave was used. Atmospheric temperatures were 20.3 ° C, and the bottom outside of the liquid-filled autoclave was covered with a heating jacket covered with insulating refractory bricks. 512.2 kg NMP 1200 kg of sodium flake sulfide (content 20.3 wt.% Na ₂ S) was placed in this autoclave.

The temperature was raised to 204 ° C. in a nitrogen stream while stirring, and 104.1 kg of water was distilled off. The autoclave was then sealed and cooled to 180 ° C. and 577.4 kg p-DCB and 400 kg NMP were added. The pressure was raised to 1 kg / cm 2 G using a nitrogen gas at a liquid temperature of 150 ° C. and then increased. Water was added to the upper part of the autoclave, and the upper part was cooled, and stirred at liquid temperature of 215 degreeC for 5 hours. The temperature was then raised and stirred for 4 hours at 255 DEG C., then lowered. The maximum pressure during the reaction was 9.8 kg / cm 2 G.

The molecular weight of the white powder product thus obtained was 41,700, the conversion was 98.7%, and thiophenol was detected at a concentration of 20 ppm in the reaction product.

Comparative Example 6

The same process as in Example 6 was repeated except that the entire autoclave was insulated with refractory bricks. The maximum pressure during the reaction was 10.3 kg / cm 2 G. The resulting slurry was filtered, washed repeatedly with hot water in a conventional manner, and dried in a 130 ° C. dryer to obtain a white powder product. The molecular weight of the obtained polyphenylene sulfide was 25,000, the conversion was 99.1%, and thiophenol in the reaction product was detected at a concentration of 280 ppm.

Example 7

As shown in FIG. 2, in a 150 L autoclave equipped with an internal cooling coil, 16.825 kg of sodium flake sulfide (containing 60.3 wt% Na ₂ S) and 39.0 kg of NMP were added thereto.

The temperature was raised to 204 degreeC in nitrogen stream, stirring, and 3.627 kg of water was distilled off. The autoclave was then sealed and cooled to 180 ° C. and 19.206 kg p-DCB and 15.6 kg NMP were added. The pressure was raised to 1 kg / cm 2 G using a nitrogen gas at a liquid temperature of 150 ° C. and then increased. The temperature was raised again after stirring for 6 hours while maintaining the liquid temperature at 215 ° C. After the temperature reached 220 ° C., a coolant of 20 ° C. was passed through the internal cooling coil. The liquid temperature was raised to 250 ° C and stirred for 3 hours while maintaining the temperature. The temperature was then lowered and at the same time the flow of coolant to the internal cooling coil was stopped. The maximum pressure during the reaction was 8.61 kg / cm 2 G.

The resulting slurry was treated as in Example 1 to obtain a white powder product.

The obtained polyphenylene sulfide had a molecular weight of 44,500 and a conversion of 99.2%. No thiophenol was detected in the reaction product.

Comparative Example 7

The polymerization was carried out as in Example 7, except that the coolant was not passed through the internal cooling coil. The maximum pressure during the reaction was 10.9 kg / cm 2 G. The molecular weight of the resulting polymer was 27,000 and the conversion was 98.8%, and thiophenol was present at a concentration of 175 ppm in the reaction product.

Example 8

As shown in FIG. 3, 256.7 kg of sodium sulphate (Na ₂ S content of 60.8 wt.%) And NMP 600 kg were placed in a ₂ m 3 autoclave equipped with a coolant jacket.

While stirring, the temperature was raised to 204 ° C. in a nitrogen stream, and 57.6 kg of water was distilled off. The autoclave was then sealed and cooled to 180 ° C. and p-DCB 293.1 kg and NMP 200 kg were added. The pressure was raised to 1 kg / cm 2 G using a nitrogen gas at a liquid temperature of 150 ° C. and then increased. It stirred at the liquid temperature of 215 degreeC for 4,5 hours, passing a 20 degreeC coolant through a jacket. Then, the temperature was raised and further stirred at the liquid temperature of 255 ° C. for 3 hours. The temperature was then lowered and at the same time cooling of the top of the autoclave was stopped. The maximum pressure during the reaction was 8.55 kg / cm 2 G.

The slurry thus obtained was filtered, washed repeatedly with hot water in a conventional manner, and then dried in a 130 ° C. dryer to obtain a white powder product. The molecular weight of the obtained polyphenylene sulfide was 48,300, the conversion was 98.9%, and thiophenol was not detected in the reaction product.

Example 9

In a 150 L autoclave shown in FIG. 4, 19.478 kg of flake sodium sulfide (content 20.1% Na ₂ S) and 45.0 kg NMP were added.

The temperature was raised to 204 ° C. in a nitrogen stream while stirring, and 4.856 kg of water was distilled off (the remaining water content was 1.08 moles per 1 mole of sodium sulfide). After that, the autoclave was sealed and cooled to 180 ° C, and 21.940 kg of p-DCB and 18.0 kg of NMP were added thereto. The pressure was raised to 1 kg / cm 2 G using a nitrogen gas at a liquid temperature of 150 ° C. and then increased. Water was sprayed on the upper part of the autoclave so that the gaseous part of the autoclave was cooled, and stirred at a liquid temperature of 215 ° C for 7 hours while cooling the upper part. A solution of 108.9 g of 1,3,5-trichlorobenzene (about 0.4 mole% relative to sodium sulfide) dissolved in 500 g of NMP was placed in an autoclave under pressure using a small high pressure pump. Then, the temperature was raised and stirred for 3 hours at a liquid temperature of 260 ° C. Cooling the top of the autoclave was then stopped by lowering the temperature and spraying water at the same time. The maximum pressure during the reaction was 8.89 kg / cm 2 G.

The resulting slurry was filtered, washed repeatedly with hot water in a conventional manner, and then dried in an oven at 120 ° C. for 5 hours to obtain a white powder product. The molecular weight of the obtained polyphenylene sulfide was 81,600, the conversion was 99.0%, and thiophenol was not detected in the reaction product.

Example 10

The same process as in Example 9 was repeated except that 21.8 g of 1,3,5-trichlorobenzene (about 0.08 mole% for sodium sulfide) were used. The maximum pressure during the reaction was 8.87 kg / cm 2 G. The weight average molecular weight of the obtained white powder polyphenylene sulfide was 51,500, the conversion was 99.2%, and thiophenol was not detected in the reaction product.

Example 11

In a 150 L autoclave shown in FIG. 5, 19.478 kg of flake sodium sulfide (content 20.1% Na ₂ S) and 45.0 kg NMP were added.

The temperature was raised to 204 ° C. in a nitrogen stream while stirring, and 5.180 kg of water was distilled off (remaining water content was 0.96 mole relative to 1 mole of sodium sulfide). After that, the autoclave was sealed and cooled to 180 ° C, and 21.940 kg of p-DCB and 18.0 kg of NMP were added thereto. The pressure was raised to 1 kg / cm 2 G using a nitrogen gas at a liquid temperature of 150 ° C. and then increased. In order to cool the gas phase of an autoclave, it stirred at 215 degreeC for 7 hours, passing a 20 degreeC coolant through the coil attached to the upper part of an autoclave outer side. A solution in which 108.9 g of 1,2,4-trichlorobenzene (about 0.4 mole% relative to sodium sulfide) was dissolved in 500 g of NMP was placed in an autoclave under pressure using a small high pressure pump. Then, the temperature was raised and stirred for further 3 hours at a liquid temperature of 260 ° C. The temperature was then lowered and at the same time cooling of the top of the autoclave was stopped. The maximum pressure during the reaction was 8.71 kg / cm 2 G.

The sludge obtained was filtered, washed repeatedly with hot water in a conventional manner, and then dried in an oven at 120 ° C. for 5 hours to obtain a white powder product. The weight average molecular weight of the obtained polyphenylene sulfide was 77,200, the conversion was 99.1%, and thiophenol was not detected in the reaction product.

Example 12

The same procedure as in Example 1 was repeated except that 40.8 g of 1,2,4-trichlorobenzene (about 0.15 mole% relative to sodium sulfide) was used. The maximum pressure during the reaction was 8.73 kg / cm 2 G. The weight average molecular weight of the white powder polyphenylene sulfide obtained was 56,700, the conversion was 99.2%, and thiophenol was not detected in the reaction product.

Example 13

In a 150 L autoclave shown in FIG. 1, 19.478 kg of sodium flakes (Na ₂ S content of 60.1% by weight) and 45.0 kg of NMP were added.

The temperature was raised to 204 ° C. in a nitrogen stream while stirring, and 5.072 kg of water was distilled off (1.0 mole to 1 mole of sodium sulfide remaining). The autoclave was then sealed and cooled to 180 ° C. and 21.984 kg p-DCB, 18.0 kg NMP and 40.8 g 1,2,4-trichlorobenzene (about 0.15 mole% relative to sodium sulfide) were added. The pressure was raised to 1 kg / cm 2 G using a nitrogen gas at a liquid temperature of 150 ° C. and then increased. In order to cool the gas phase part of an autoclave, it stirred at the liquid temperature of 215 degreeC for 7 hours, passing a 20 degreeC coolant through the coil attached to the upper part of an autoclave exterior. Then, the temperature was raised and stirred for further 3 hours at a liquid temperature of 260 ° C. The temperature was lowered and cooling at the top of the autoclave was also stopped. The maximum pressure during the reaction was 8.69 kg / cm 2 G.

The resulting slurry was filtered, washed repeatedly with hot water in a conventional manner, and then dried in an oven at 120 ° C. for 5 hours to obtain a white powder product. The weight average molecular weight of the obtained polyphenylene sulfide was 60,800, the conversion was 99.1%, and thiophenol was not detected in the reaction product.

Example 14

The same procedure as in Example 13 was repeated except that 54.5 g (about 0.2 mole% of sodium sulfide) of 1,3,5-trichlorobenzene was used instead of 1,2,4-trichlorobenzene. The maximum pressure during the reaction was 8.72 kg / cm 2 G. The weight average molecular weight of the white powder polyphenylene sulfide obtained was 70,800, the conversion was 98.8%, and thiophenol was not detected in the reaction product.

Example 15

Into a 4 m 3 autoclave shown in FIG. 4, 512.9 kg of flaky sodium sulfide (content 20.1% Na ₂ S) and 1120 kg NMP were added.

The temperature was raised to 204 ° C. in a nitrogen stream while stirring, and 131.6 kg of water was distilled off (the remaining water content was 1.05 mole% with respect to 1 mol of sodium sulfide). The autoclave was then sealed and cooled to 180 ° C. and 583.6 kg of p-DCB, 400 kg of NMP and 1.851 kg of 1,2,4-trichlorobenzene (approximately 0.25 mole% for sodium sulfide) were added. The pressure was raised to 1 kg / cm 2 G using a nitrogen gas at a liquid temperature of 150 ° C. and then increased. After the liquid temperature reached 230 ° C., water was sprayed on top of the autoclave to cool the gas phase portion of the autoclave. Then, the temperature was raised to 260 ° C and maintained at that temperature for 3 hours. The temperature was then lowered and at the same time the cooling on the top of the autoclave was stopped. The maximum pressure during the reaction was 8.82 g / cm 2 G.

The resulting slurry was filtered, washed repeatedly with hot water in a conventional manner, and then dried in an oven at 120 ° C. for 5 hours to obtain a white powder product. The weight average molecular weight of the obtained polyphenylene sulfide was 53,800, the conversion was 98.7%, and thiophenol was not detected in the reaction product.

Comparative Example 8

The same process as in Example 9 was repeated except that water was sprayed on the outer upper side of the autoclave and not cooled. The maximum pressure during the reaction was 10.5 kg / cm 2 G. The weight average molecular weight of the white powder polyphenylene sulfide obtained was 32,500, the conversion was 99.3%, and thiophenol was present in the reaction product at a concentration of 150 ppm.

Comparative Example 9

The same procedure as in Example 9 was repeated except that the amount of 1,3,5-trichlorobenzene was 326.8 g (about 1.6 mole% relative to sodium sulfide). The maximum pressure during the reaction was 8.70 kg / cm 2 G. The obtained polyphenylene sulfide was not completely dissolved in 1-chloronaphthalene and thus the molecular weight could not be determined. The conversion was 98.6% and no thiophenol was detected in the reaction product. The viscosity was so high that it was impossible to determine the melt viscosity at 300 ° C.

Comparative Example 10

In the drying process, the same process as in Example 10 was repeated, except that 83.8 kg of water (remaining water content was 1.75 moles of distilled sodium per 1 mole of sodium sulfide and not cooled by spraying water on the upper portion of the autoclave). The maximum pressure during the reaction was 13.7 kg / cm 2 G The resulting polyphenylene sulfide was brownish white powder, weight average molecular weight was 18,400, conversion was 99.6%, and thiophenol was present in the reaction product at a concentration of 1,120 ppm. did.

Comparative Example 11

The same process as in Example 13 was repeated except that no coolant was passed through the coil attached to the outer upper part of the autoclave. The maximum pressure during the reaction was 10.8 kg / cm 2 G. The obtained polyphenylene sulfide was a brownish white powder, the weight average molecular weight was 33,600, the conversion was 99.2%, and thiophenol was present in the reaction product at a concentration of 140 ppm.

Comparative Example 12

The same process as in Example 13 was repeated except that 1,2,4-trichlorobenzene was not added. The maximum pressure during the reaction was 8.69 kg / cm 2 G. The weight average molecular weight of polyphenylene sulfide was 42,800, the conversion was 99.2%, and thiophenol was not detected in the reaction product.

Example 16

In a 150 L autoclave shown in FIG. 1, 19.47 kg of flake sodium sulfide (content 20.1% Na ₂ S) and 45.0 kg NMP were added.

The temperature was raised to 204 ° C. in a nitrogen stream while stirring, and 5.072 kg of water was distilled off (the remaining water content was 1.0 mole to 1 mole of sodium sulfide).

The autoclave was then sealed and cooled to 180 ° C., p-DCB 22.0501 kg, NMP 18.0 kg and 1,2,4-trichlorobenzene (approximately 0.80 mole% for sodium sulfide) were purged with nitrogen gas at a liquid temperature of 150 ° C. After pressurizing to 1 kg / cm <2> G, the temperature was raised. In order to cool the gas phase part of an autoclave, it stirred at the liquid temperature of 205 degreeC for 2 hours, passing a 20 degreeC coolant through the coil attached to the outer upper part of an autoclave. Then the temperature was raised and the liquid temperature was further stirred at 265 ° C. for 3 hours. The temperature was lowered and cooling at the top of the autoclave was also stopped. The maximum pressure during the reaction was 9.65 kg / cm 2 G.

The slurry thus obtained was filtered, washed with warm water according to a conventional method, and dried in an oven at 120 ° C. for 5 hours to obtain a white powder product. The weight average molecular weight of the obtained polyphenylene sulfide was 97,500, the conversion was 99.4%, and thiophenol was not detected in the reaction product.

[Processability Evaluation]

The radioactivity of the polyphenylene sulfides prepared in Examples 9 and 13 and Comparative Examples 7 and 8 was measured as follows.

The tension applied to the strands while melting the polyphenylene sulfide at 320 ° C. using IB capillograph (L / D = 10/1 manufactured by Toyo Seiki Seisakusho Co., Ltd.) at a predetermined constant speed. Was measured. The results are shown in Table 1 with the same method being continued while gradually increasing the winding speed from 5 m / min. The high molecular weight polyphenylene sulfides prepared in this example showed stable melt tension and low cleavage over a wide winding speed range. They have therefore proved to be suitable for spinning and blow molding.

Claims (7)

A method of preparing polyarylene sulfide by reacting an alkali metal sulfide and a dihaloaromatic compound in an organic amide solvent in a sealed pressurized reactor, wherein the gaseous portion of the reactor is cooled to condense and condense a portion of the gas phase of the reactor. Method for producing a polyarylene sulfide, characterized in that the liquid is refluxed to the liquid phase of the reactor. The process according to claim 1, wherein the reaction takes place in at least two stages having different temperatures. The method for producing polyarylene sulfide according to claim 1, wherein 0.005 to 1.5 mol% of the polyhaloaromatic compound is further reacted based on the alkali metal sulfide. 4. A process according to claim 3, wherein the water content in the reaction system is less than 1.7 moles per mole of alkali metal sulfide. 4. A process according to claim 3, wherein the reaction is carried out in at least two stages with different temperatures. An apparatus for producing a polyarylene sulfide in which an alkali metal sulfide and a dihaloaromatic compound are reacted in an organic amide solvent, the apparatus cooling the gas phase portion of the reactor for condensing a part of the gas phase of the reactor, A device for producing a polyarylene sulfide, comprising a device for recovering a liquid to a liquid phase of a reactor. 7. The apparatus of claim 6, wherein the apparatus comprises: (a) a vice cooling coil wound on the top outer wall of the reactor, (b) an internal cooling coil mounted inside the top of the reactor, and (c) a coolant mounted on the top outer wall of the reactor. Apparatus for producing a polyarylene sulfide, characterized in that it comprises a jacket, (d) a unit for spraying or spraying liquid or gas directly on the upper outer wall of the reactor, or (e) a reflux condenser.