阅读说明：本技术 聚芳硫醚树脂的制造方法 (Method for producing polyarylene sulfide resin ) 是由 奈良早织 渡边英树 角木将哉 茨木拓 井上敏 于 2018-06-26 设计创作，主要内容包括：提供：在能通过水解而开环的脂肪族系环状化合物的存在下,使二卤代芳香族化合物与硫化剂进行聚合反应的聚芳硫醚树脂的制造方法中,抑制制造装置的腐蚀、减少得到的聚芳硫醚树脂中的源自制造装置的金属原子的含量的方法。进一步详细而言,提供一种聚芳硫醚树脂的制造方法,其特征在于,具备如下脱水工序(1)：在二卤代芳香族化合物的存在下,在大气压下使包含水的硫化剂、和能通过水解而开环的脂肪族系环状化合物升温至液温为90℃以上至170℃以下的范围后,边维持液温边减压至压力为30〔kPa abs〕以上至80〔kPa abs〕以下的范围,边进行脱水,得到混合物。(Providing: a process for producing a polyarylene sulfide resin by polymerizing a dihalo-aromatic compound with a vulcanizing agent in the presence of an aliphatic cyclic compound which can be ring-opened by hydrolysis, wherein the process comprises inhibiting the corrosion of the production apparatus and reducing the content of metal atoms originating in the production apparatus in the obtained polyarylene sulfide resin. More specifically, the present invention provides a method for producing a polyarylene sulfide resin, comprising the following dehydration step (1): a vulcanizing agent containing water and an aliphatic cyclic compound which can be ring-opened by hydrolysis are heated to a liquid temperature in the range of 90 ℃ to 170 ℃ under atmospheric pressure in the presence of a dihalo-aromatic compound, and then dehydrated while maintaining the liquid temperature and reducing the pressure to a pressure in the range of 30 [ kPa abs ] to 80 [ kPa abs ], to obtain a mixture.)

1. A process for producing a polyarylene sulfide resin, which comprises reacting a dihalogenated aromatic compound with a vulcanizing agent in the presence of an aliphatic cyclic compound which can be ring-opened by hydrolysis,

the production method comprises the following dehydration step (1): a vulcanizing agent containing water and an aliphatic cyclic compound which can be ring-opened by hydrolysis are heated to a liquid temperature in the range of 90 ℃ to 170 ℃ under atmospheric pressure in the presence of a dihalo-aromatic compound, and then dehydrated while maintaining the liquid temperature and reducing the pressure to a pressure in the range of 30 [ kPa abs ] to 80 [ kPa abs ], to obtain a mixture.

2. The production process according to claim 1, wherein the dihalo-aromatic compound is contained in an amount of 0.2 mol or more and 5.0 mol or less based on 1 mol of the total sulfur atoms in the vulcanizing agent.

3. The production process according to claim 1, wherein the amount of water present in the reaction system after the completion of the dehydration step (1) is in the range of 0.4 mol or less based on 1 mol of the total sulfur atoms in the sulfidizing agent.

4. The production method according to claim 1, wherein the aliphatic cyclic compound is in a range of 0.01 mol or more and 0.9 mol or less relative to 1 mol of the total of sulfur atoms in the vulcanizing agent.

5. The production method according to claim 1, wherein the vulcanizing agent is an alkali metal sulfide, or an alkali metal hydrosulfide and an alkali metal hydroxide.

6. The production method according to claim 1, wherein the mixture is a slurry containing a sulfidizing agent as an anhydrous solid after the dehydration step (1) is completed.

7. The production method according to claim 1, further comprising a polymerization step of: the mixture obtained through the dehydration step (1) is heated to polymerize the dihalo-aromatic compound in such a range that the amount of water existing in the reaction system is 0.4 mol or less based on 1 mol of the dihalo-aromatic compound.

8. The manufacturing method according to claim 1, comprising the following steps of: a dehydration step (2) for adding an aprotic polar organic solvent to the mixture obtained in the dehydration step (1) to distill off water and dehydrate the mixture;

and a polymerization step of polymerizing the mixture obtained in the dehydration step (2) so that the amount of water existing in the reaction system is less than 0.03 mol based on 1 mol of the dihalo-aromatic compound.

9. The production method according to claim 1, wherein the contact portion of the reaction apparatus with the raw material or the mixture obtained after the reaction in the dehydration step (1) is composed of at least 1 material selected from the group consisting of titanium, zirconium and a nickel alloy.

10. A method for producing a polyarylene sulfide resin composition, comprising the steps of: a step of producing a polyarylene sulfide resin by the production method according to claim 1; and a step of compounding the polyarylene sulfide resin obtained with at least 1 other component selected from the group consisting of a filler, a thermoplastic resin other than the polyarylene sulfide resin, an elastomer, a crosslinkable resin having 2 or more functional groups, and a silane coupling agent, heating the mixture to a temperature of not less than the melting point of the polyarylene sulfide resin, and melt-kneading the mixture.

11. A method for producing a polyarylene sulfide resin molded article, comprising the steps of: a step of producing a polyarylene sulfide resin composition by the production method according to claim 10; and a step of melt-molding the polyarylene sulfide resin composition obtained.

Technical Field

The present invention relates to a method for efficiently producing a linear high molecular weight polyarylene sulfide resin.

Background

Polyarylene sulfide resins (hereinafter, abbreviated as "PAS resin" in some cases) typified by polyphenylene sulfide resins (hereinafter, abbreviated as "PPS resin" in some cases) are excellent in heat resistance, chemical resistance and the like, and are widely used for electric and electronic parts, automobile parts, water heater parts, fibers, film applications and the like.

As a method for producing a polyarylene sulfide resin, for example, the following methods are known: an aqueous alkali metal sulfide or N-methylpyrrolidone in an amount of less than 1 mol relative to 1 mol of the aqueous alkali metal sulfide and a polyhaloaromatic compound are mixed, and the mixture is azeotropically dehydrated to obtain a slurry containing fine particulate anhydrous alkali metal sulfide, which is then heated to effect polymerization (see, for example, patent documents 1 and 2). In the above method, a high molecular weight polyarylene sulfide resin can be efficiently produced by removing a small amount of water such as crystal water remaining in a reaction system which induces a side reaction and then performing a polymerization reaction, but since a highly basic vulcanizing agent needs to be dehydrated at a high temperature, a contact portion with a raw material in a reaction apparatus such as a reaction vessel is easily corroded, and therefore, a corrosion-resistant metal member such as titanium or zirconium has to be used. However, it is known that even so, the metal member corrodes, promoting consumption of the metal member. Therefore, a method for producing polyarylene sulfide resin is desired which suppresses the consumption of the metal member.

Further, the polyarylene sulfide resin obtained contains metal atoms derived from the metal member eluted due to consumption of the metal member at the contact portion, but it is difficult to remove these metal atoms by a normal washing operation. In particular, in recent years, the thickness of molded articles using polyarylene sulfide resins has been reduced, and polyarylene sulfide resins having higher quality than conventional ones have been required, and reduction of the content of metal atoms in polyarylene sulfide resins originating from a reaction apparatus has become an urgent problem.

Disclosure of Invention

Problems to be solved by the invention

Accordingly, an object to be solved by the present invention is to provide: a process for producing a polyarylene sulfide resin by polymerizing a dihalo-aromatic compound with a vulcanizing agent (sulfurizing agent) in the presence of an aliphatic cyclic compound which can be ring-opened by hydrolysis, wherein the process comprises inhibiting the corrosion of the production apparatus and reducing the content of metal atoms originating from the production apparatus in the obtained polyarylene sulfide resin.

Means for solving the problems

The present inventors have made diligent efforts to solve the above problems, and as a result, have found that: the present inventors have completed the present invention by finding that, when a sulfurizing agent containing water and an aliphatic cyclic compound which can be ring-opened by hydrolysis are dehydrated in the presence of a dihalo-aromatic compound under reduced pressure, the corrosion of the contact part can be reduced as compared with the conventional case, that is, as compared with the case of dehydration under atmospheric pressure, and the content of metal atoms originating from the production apparatus in the obtained polyarylene sulfide resin can be further reduced.

That is, the present invention relates to a process for producing a polyarylene sulfide resin, which comprises reacting a dihalogenated aromatic compound with a vulcanizing agent in the presence of an aliphatic cyclic compound which can be ring-opened by hydrolysis,

reacting a dihalo-aromatic compound with a sulfurizing agent in the presence of an aliphatic cyclic compound which can be ring-opened by hydrolysis,

the production method comprises the following dehydration step (1): a vulcanizing agent containing water and an aliphatic cyclic compound which can be ring-opened by hydrolysis are heated to a liquid temperature in the range of 90 ℃ to 170 ℃ under atmospheric pressure in the presence of a dihalo-aromatic compound, and then dehydrated while maintaining the liquid temperature and reducing the pressure to a pressure in the range of 30 [ kPa abs ] to 80 [ kPa abs ], to obtain a mixture.

Further, the present invention relates to a method for producing a polyarylene sulfide resin composition, including the steps of: a step of producing a polyarylene sulfide resin by the production method; and a step of compounding the polyarylene sulfide resin obtained with at least 1 other component selected from the group consisting of a filler, a thermoplastic resin other than the polyarylene sulfide resin, an elastomer, a crosslinkable resin having 2 or more functional groups, and a silane coupling agent, heating the mixture to a temperature of not less than the melting point of the polyarylene sulfide resin, and melt-kneading the mixture.

Further, the present invention relates to a process for producing a polyarylene sulfide resin molded article, which comprises the step of producing a polyarylene sulfide resin composition by the above production process; and a step of melt-molding the polyarylene sulfide resin composition obtained.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, there can be provided: a process for producing a polyarylene sulfide resin by polymerizing a dihalo-aromatic compound with a vulcanizing agent in the presence of an aliphatic cyclic compound which can be ring-opened by hydrolysis, wherein the process comprises inhibiting the corrosion of the production apparatus and reducing the content of metal atoms originating in the production apparatus in the obtained polyarylene sulfide resin.

Detailed Description

The process for producing a polyarylene sulfide resin of the present invention is characterized in that,

reacting a dihalo-aromatic compound with a sulfurizing agent in the presence of an aliphatic cyclic compound which can be ring-opened by hydrolysis,

the production method comprises the following dehydration step (1): a vulcanizing agent containing water and an aliphatic cyclic compound which can be ring-opened by hydrolysis are heated to a liquid temperature in the range of 90 ℃ to 170 ℃ under atmospheric pressure in the presence of a dihalo-aromatic compound, and then dehydrated while maintaining the liquid temperature under reduced pressure in the range of 30 [ kPa abs ] to 80 [ kPa abs ], to obtain a mixture. The following is a detailed description.

Dehydration step (1)

The present invention is essentially provided with the following dehydration step (1): a vulcanizing agent containing water and an aliphatic cyclic compound which can be ring-opened by hydrolysis are heated to a liquid temperature in the range of 90 ℃ to 170 ℃ under atmospheric pressure in the presence of a dihalo-aromatic compound, and then dehydrated while maintaining the liquid temperature and reducing the pressure to a pressure in the range of 30 [ kPa abs ] to 80 [ kPa abs ], to obtain a mixture.

The dehydration step (1) is a step of reacting a vulcanizing agent containing water and an aliphatic cyclic compound which can be ring-opened by hydrolysis while dehydrating in the presence of a dihalo-aromatic compound. Comprises the following steps: this step can efficiently remove the water content existing in the reaction system to the outside of the system, and promote the hydrolysis of the aliphatic cyclic compound to form a mixture containing at least a water-free vulcanizing agent and an alkali metal salt of the hydrolysate of the aliphatic cyclic compound. In the present invention, by carrying out dehydration under reduced pressure, corrosion of the contact portion of the reaction apparatus with the raw material or the mixture can be reduced as compared with the case of carrying out dehydration under a pressure condition of atmospheric pressure or more, and the content of the metal atom derived from the contact portion in the obtained polyarylene sulfide resin can be reduced.

The dihalo-aromatic compound used in the present invention functions as a solvent for ensuring the fluidity of the obtained mixture in the dehydration step (1), and can be used as a polymerization raw material in the subsequent polymerization step. Examples of the dihalo-aromatic compound used in the present invention include: p-dihalobenzene, m-dihalobenzene, o-dihalobenzene, 2, 5-dihalotoluene, 1, 4-dihalonaphthalene, 1-methoxy-2, 5-dihalobenzene, 4' -dihalobiphenyl, 3, 5-dihalobenzoic acid, 2, 4-dihalobenzoic acid, 2, 5-dihalonitrobenzene, 2, 4-dihaloanisole, p, p ' -dihalodiphenyl ether, 4 ' -dihalobenzophenone, 4 ' -dihalodiphenylsulfone, 4 ' -dihalodiphenylsulfoxide, 4 ' -dihalodiphenylsulfide, and a compound having an alkyl group having 1 to 18 carbon atoms as a core substituent on an aromatic ring of each of the above compounds. The halogen atom contained in each of the above compounds is preferably a chlorine atom or a bromine atom, and particularly preferably a chlorine atom.

Among the dihalo-aromatic compounds, p-dichlorobenzene, m-dichlorobenzene, 4 '-dichlorobenzophenone and 4, 4' -dichlorodiphenyl sulfone are preferable, and p-dichlorobenzene is particularly preferable, from the viewpoint of improving the mechanical strength and moldability of the finally obtained polyarylene sulfide resin in the case of efficiently producing a linear polyarylene sulfide resin.

When a part of the polymer structure of the linear polyarylene sulfide resin is desired to have a branched structure, it is preferable to use a part of 1,2, 3-trihalobenzene, 1,2, 4-trihalobenzene, 1,3, 5-trihalobenzene, 1,2,3, 5-tetrahalobenzene, 1,2,4, 5-tetrahalobenzene, or 1,4, 6-trihalonaphthalene in combination with the dihaloaromatic compound. The halogen atom contained in each of the above compounds is also preferably a chlorine atom or a bromine atom, and particularly preferably a chlorine atom. When used in combination, the dihalo-aromatic compound is preferably used in a range of 0.001 mol or more and 3 mol or less based on 100 mol of the dihalo-aromatic compound while focusing attention on gelation.

In the dehydration step (1), the amount of the dihalo-aromatic compound to be added is preferably 0.2 mol or more, more preferably 0.3 mol or more to preferably 5.0 mol or less, more preferably 2.0 mol or less based on 1 mol of the sulfur atom of the sulfidizing agent. When the amount is 0.2 mol or more, the total amount of heat required for heating can be suppressed preferably from the viewpoint of securing the fluidity of the mixture, and when the amount is 5.0 mol or less, the amount is preferably from the viewpoint of excellent productivity.

Examples of the vulcanizing agent used in the present invention include an alkali metal sulfide, or an alkali metal hydrosulfide and an alkali metal hydroxide. In general, the alkali metal sulfide or the alkali metal hydrosulfide is used as a raw material of the polyarylene sulfide resin in the form of a so-called hydrate containing crystal water, and in this case, a liquid or solid hydrate having a solid content concentration in the range of preferably 10% by mass or more, more preferably 35% by mass or more to preferably 80% by mass or less, and more preferably 65% by mass or less is used.

Examples of the alkali metal sulfide used in the present invention include compounds such as lithium sulfide, sodium sulfide, potassium sulfide, rubidium sulfide, and cesium sulfide. These may be used alone or in combination of 2 or more. Among these alkali metal sulfides, sodium sulfide and potassium sulfide are preferred, and sodium sulfide is particularly preferred.

Further, the alkali metal sulfide can be obtained by reacting the alkali metal hydrosulfide with the alkali metal hydroxide, but it may be prepared in the same reaction system as the dehydration step (1), or may be prepared in advance in a reaction system different from the dehydration step (1). Specific examples of the alkali metal hydroxide include lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, and cesium hydroxide. Among them, lithium hydroxide, sodium hydroxide and potassium hydroxide are particularly preferable, and sodium hydroxide is particularly preferable. The alkali metal hydroxide is preferably used in the form of an aqueous solution, and the concentration thereof is preferably in the range of 10 mass% or more and 50 mass% or less. Examples of the alkali metal hydrosulfide used in the present invention include lithium hydrosulfide, sodium hydrosulfide, potassium hydrosulfide, rubidium hydrosulfide, cesium hydrosulfide, and the like. These may be used alone or in combination of 2 or more. Of these alkali metal hydrosulfides, sodium hydrosulfide and potassium hydrosulfide are preferred, and sodium hydrosulfide is particularly preferred. Further, the alkali metal hydrosulfide may be obtained by reacting hydrogen sulfide with an alkali metal hydroxide, but it may be prepared in advance outside the reaction system.

As the aliphatic cyclic compound used in the present invention, any known compound can be used without particular limitation as long as it can be ring-opened by hydrolysis, and specific examples of such aliphatic cyclic compounds include aliphatic cyclic amide compounds such as N-methyl-2-pyrrolidone (hereinafter, abbreviated as NMP in some cases), N-cyclohexyl-2-pyrrolidone, N-methyl-epsilon-caprolactam, formamide, acetamide, N-methylformamide, N-dimethylacetamide, 2-pyrrolidone, epsilon-caprolactam, hexamethylphosphoramide, tetramethylurea, N-dimethylacrylamide, 1, 3-dimethyl-2-imidazolidinone acid, and the like, amidourea, and lactams. Among them, aliphatic cyclic amide compounds are preferable, and NMP is particularly preferable, from the viewpoint of good reactivity.

In this case, the amount of the aliphatic cyclic compound to be charged is preferably in the range of 0.01 to 4.0 moles per 1 mole of sulfur atom in the vulcanizing agent, and in the case of producing a polyarylene sulfide resin having a high molecular weight, the amount is preferably in the range of 0.01 to 0.9 moles, more preferably less than 0.9 moles, and still more preferably 0.5 moles per 1 mole of sulfur atom in the vulcanizing agent.

In the dehydration step (1), dehydration is carried out under reduced pressure. More specifically, the following methods can be mentioned:

(1) a vulcanizing agent containing water and an aliphatic cyclic compound which can be ring-opened by hydrolysis are heated under atmospheric pressure in the presence of a dihalo-aromatic compound so that the liquid temperature becomes preferably 90 ℃ or higher, more preferably 110 ℃ or higher, further preferably 120 ℃ or higher, particularly preferably in a range exceeding 130 ℃ or higher, most preferably 140 ℃ or higher, to preferably 170 ℃ or lower, more preferably 160 ℃ or lower, further preferably 150 ℃ or lower, and then the pressure is reduced to a range of preferably 30 [ kPa abs ], more preferably 35 [ kPa abs ], further preferably 40 [ kPa abs ] or higher to preferably 80 [ kPa abs ], more preferably 70 [ kPa abs ] or lower, further preferably 60 [ kPa abs ] or lower while maintaining the liquid temperature, thereby carrying out dehydration.

In the above method, the dehydration is preferably carried out as follows: the pressure is controlled until the pressure is within a prescribed pressure range from atmospheric pressure so that the liquid temperature is maintained within a range of preferably ± 10 ℃, more preferably within a range of ± 5 ℃. The pressure gradient at this time varies depending on the volume of the reaction vessel, the total amount of the raw materials, etc., and therefore cannot be limited in general, but is preferably in a range exceeding-3 [ kPa abs/min ], more preferably in a range exceeding-2 [ kPa abs/min ], and still more preferably in a range exceeding-1 [ kPa abs/min ]. On the other hand, the upper limit is not particularly limited, but is preferably in the range of-0.001 [ kPaabs/min ] or less, more preferably-0.01 [ kPa abs/min ] or less, from the viewpoint of productivity.

In the above method, the liquid temperature is adjusted by measuring the liquid temperature and controlling the pressure to the temperature to be maintained, and when the temperature exceeds the temperature range to be maintained, the amount of heat input into the reaction system from the heating apparatus may be controlled. This control may be performed manually, and is preferably performed automatically by a known automatic control method such as sequence control, feedback control, or feedforward control. A time interval must be involved in the control, and therefore a certain temperature range is allowed between the desired control liquid temperature and the actual liquid temperature. The temperature range is preferably within a range of ± 10 ℃ and more preferably within a range of ± 5 ℃ with respect to the temperature to be controlled.

The dehydration was carried out as follows: while controlling the liquid temperature and the pressure within the above ranges, the mixture of the aliphatic cyclic compound, water and the dihalo-aromatic compound is distilled by opening a valve (valve) of a pipe communicating the distillation apparatus from the reaction system. Examples of the distillation include the following methods: after separating the aliphatic cyclic compound, a mixed vapor mainly composed of water and the dihalo-aromatic compound is condensed by a condenser, the water and the dihalo-aromatic compound are separated by a decanter or the like, and the dihalo-aromatic compound subjected to azeotropic distillation is returned to the reaction system. The separated aliphatic cyclic compound, and the separated dihalo-aromatic compound are preferably returned to the reaction system, and in the case where they are not returned, the aliphatic cyclic compound and/or the dihalo-aromatic compound may be additionally charged in an amount corresponding to the amount of azeotropic distillation, or the aliphatic cyclic compound and/or the dihalo-aromatic compound may be excessively charged in advance in consideration of the amount removed by azeotropic distillation.

As described above, the dehydration step (1) of the present invention is a step of: the aliphatic cyclic compound which is discharged outside the reaction system by dehydration treatment and can be ring-opened by hydrolysis is hydrolyzed to produce an anhydrous sulfidizing agent, preferably an anhydrous alkali metal sulfide. When excessive water is present in the reaction system after the dehydration treatment, a large amount of by-products are produced in the subsequent polymerization step, and the growth termination reaction is induced, so that the chain extension reaction of the polyarylene sulfide resin is suppressed, and the viscosity increase or the molecular weight increase tends to be inhibited. Therefore, the total amount of water in the reaction system after the dehydration step (1) is preferably as small as possible, and specifically, the amount of water used in the dehydration step (1) is preferably in a range of more than 0.1 mol, more preferably 0.6 mol or more to preferably 0.99 mol or less, and still more preferably 0.96 mol or less, based on 1 mol of sulfur atoms in the sulfidizing agent. The "total water content in the reaction system" is the total mass of all of the water consumed in the hydrolysis of the aliphatic cyclic compound, the residual crystal water in a trace amount in the sulfurizing agent, and the water present in the other reaction system.

Furthermore, the amount of water present in the reaction system after the dehydration step (1) is preferably in a range of 0.4 mol or less, more preferably in a range of 0.4 mol or less for 1 mol of sulfur atoms in the sulfidizing agent in the reaction system, and is more preferably in a range of 0.4 mol or less for detection, and is in a range of excellent dehydration efficiencyFurther, the ratio is preferably in the range of 0.03 mol or more and 0.11 mol or less. Here, the "amount of water present in the reaction system" means water other than the water consumed for hydrolysis of the aliphatic cyclic compound, i.e., water of crystallization, H, out of the total amount of water in the reaction system₂The total amount of water (hereinafter, these are referred to as "crystal water and the like") present in the reaction system in the form of O and the like.

In this manner, in the present invention, by carrying out dehydration under reduced pressure, even if the liberation of crystal water in the sulfidizing agent is promoted at a lower heating temperature, the water in the reaction system, which is a cause of the side reaction in the polymerization step, can be effectively removed, and at the same time, the water can be converted into a hydrolysate of an aliphatic cyclic compound which is considered to exhibit a polymerization promoting action, and as a result, the side reaction at the time of polymerization can be suppressed with the promotion of polymerization.

Dehydration step (2)

The present invention may further include the following dehydration step (2) as an arbitrary step: an aprotic polar organic solvent is further added to the mixture obtained in the dehydration step (1), and water is distilled off and dehydrated. In the dehydration step (2), the amount of the aprotic polar solvent charged into the reaction system is preferably in the range of 0.5 mol or more and 5 mol or less, relative to 1 mol of sulfur atoms in the sulfidizing agent. When the amount of water existing in the reaction system is set to a range of less than 0.03 mol relative to 1 mol of sulfur atoms in the sulfidizing agent, the dehydration efficiency tends to be very low, and therefore, in such a case, the dehydration step (2) is further performed immediately after the dehydration step (1), and the amount of water contained in the reaction system at the end of the dehydration step (2) can be adjusted to a range of less than 0.03 mol relative to 1 mol of sulfur atoms in the sulfidizing agent, preferably to a range of less than 0.03 mol, more preferably to a range of not less than 0.01 mol.

The dehydration in the dehydration step (2) may be carried out under the conditions of a liquid temperature in the range of 90 ℃ to 220 ℃ inclusive and in the range of 30 [ kPaabs ] to 202 [ kPa abs ], wherein the dehydration treatment under reduced pressure is carried out under the same conditions as in the dehydration step (1), that is, the heating is performed so that the liquid temperature is preferably 90 ℃ or higher, more preferably 110 ℃ or higher, still more preferably 130 ℃ or higher to 160 ℃ or lower, and still more preferably 150 ℃ or lower, and it is preferable from the viewpoint of efficiently dehydrating at a lower liquid temperature when dehydrating under reduced pressure so that the dehydration is carried out in a range of preferably 30 [ kPa abs ] or more, more preferably 35 [ kPa abs ] or more, still more preferably 40 [ kPa abs ] or more to preferably 80 [ kPa abs ] or less, still more preferably 70 [ kPa abs ] or less, and still more preferably 60 [ kPa abs ] or less.

From the viewpoint of sharing manufacturing facilities and improving productivity, it is preferable that the dehydration step (2) is performed in the same reaction vessel as the dehydration step (1), and from the viewpoint of improving the resin production per unit time, it is also preferable that the dehydration step (1) and the polymerization step are performed using a different reaction vessel.

Polymerization step

The present invention then comprises the following polymerization steps: the mixture obtained through the dehydration step (1) is heated in a range where the amount of water existing in the reaction system is 0.4 mol or less based on 1 mol of the dihalo-aromatic compound, and a polymerization reaction is carried out. In the case where the dehydration step (2) is performed after the dehydration step (1), the mixture obtained through the dehydration step (2) may be heated to a temperature in the range of less than 0.03 mol of the amount of water existing in the reaction system based on 1 mol of the dihalo-aromatic compound to perform the polymerization reaction.

The polymerization step is as follows: the mixture obtained through the dehydration step (1) or the dehydration step (2) is heated to a temperature of 200 ℃ or higher and 300 ℃ or lower in a closed reaction vessel to carry out a polymerization reaction.

In the polymerization step, the polymerization reaction conditions are not particularly limited, and the reaction is preferably carried out at a temperature at which the polymerization reaction can be easily carried out, that is, in a range of 200 ℃ to 300 ℃, preferably 210 ℃ to 280 ℃, and more preferably 215 ℃ to 250 ℃.

As described above, the dihalo-aromatic compound as the polymerization raw material is charged in the dehydration step (1) and then removed by azeotropic distillation by distillation, and therefore, in consideration of the amount of azeotropic distillation removal, an excess amount of the dihalo-aromatic compound is charged in advance in the dehydration step, or the dihalo-aromatic compound is additionally charged until the start of the polymerization step, and the reaction is carried out so that the proportion of the dihalo-aromatic compound in the reaction system is adjusted to be preferably 0.8 mol or more, more preferably 0.9 mol or more to preferably 1.2 mol or less, still more preferably 1.1 mol or less, and particularly preferably equimolar with respect to 1 mol of the sulfur atom of the sulfidizing agent.

The smaller the amount of water present in the reaction system at the start of the polymerization, the better, for example, is in the range of 0.4 mol or less, preferably in the range of not less than the detection limit (mol) to preferably 0.4 mol or less, more preferably 0.11 mol or less, further preferably 0.08 mol or less, particularly preferably 0.03 mol or less, and most preferably 0.01 mol or less based on 1 mol of the sulfur atom of the sulfidizing agent. Since water is generated as the polymerization reaction proceeds, it is preferable that water is generated in a range of 0.1 mol or more and 0.3 mol or less based on 1 mol of the sulfur atom of the sulfidizing agent at the time of completion of the polymerization reaction in the polymerization step, and it is more preferable that the above range is satisfied from the time when the conversion of the dihalo-aromatic compound exceeds 80 mol%, more preferably from the time when the conversion exceeds 60 mol%, and even more preferably immediately after the start of the polymerization.

The conversion of the dihalo-aromatic compound is a value represented by the following formula.

Conversion (%) - (amount of charge-residue)/amount of charge × 100

The "amount charged" represents the mass of the dihalo-aromatic compound charged into the reaction system, and the "amount remaining" represents the mass of the dihalo-aromatic compound remaining in the reaction system.

Post-treatment step

The reaction mixture containing the polyarylene sulfide resin obtained by the polymerization reaction may be subjected to a post-treatment process. The post-treatment step is not particularly limited as long as it is a known method, and examples thereof include the following methods: after the polymerization reaction is finished, firstly, distilling off the solvent under reduced pressure or normal pressure directly or after adding acid or alkali into the reaction mixture, then washing the solid after distilling off the solvent for 1 or more times by using solvents such as water, acetone, methyl ethyl ketone, alcohols and the like, and further carrying out neutralization, water washing, filtration and drying; or, after the polymerization reaction is completed, a method of adding water, a solvent (a solvent which is soluble in the polymerization solvent used and is a poor solvent for at least the polyarylene sulfide resin) such as acetone, methyl ethyl ketone, alcohols, ethers, halogenated hydrocarbons, aromatic hydrocarbons, aliphatic hydrocarbons, etc. as a settling agent to the reaction mixture to settle a solid product such as the polyarylene sulfide resin, inorganic salts, etc., and filtering, washing, and drying the solid product; or, after the polymerization reaction is completed, a reaction solvent (or an organic solvent having an equivalent solubility to the low-molecular polymer) is added to the reaction mixture, stirred, filtered, and after the low-molecular polymer is removed, washed with a solvent such as water, acetone, methyl ethyl ketone, or alcohols 1 or 2 times or more, followed by neutralization, water washing, filtration, and drying; and the like.

In the post-treatment method of the above example, the polyarylene sulfide resin may be dried in vacuum, or in air or an inert gas atmosphere such as nitrogen.

The polyarylene sulfide resin thus obtained can be used as it is for various molding materials and the like, and can be subjected to heat treatment in air or oxygen-enriched air or under reduced pressure to be oxidatively crosslinked. The temperature of the heat treatment varies depending on the target crosslinking treatment time and the treatment atmosphere, but is preferably in the range of 180 ℃ to 270 ℃. The heat treatment may be performed in a state where the polyarylene sulfide resin is melted at a temperature equal to or higher than the melting point of the polyarylene sulfide resin using an extruder or the like, and the polyarylene sulfide resin is more likely to be thermally deteriorated, and therefore, it is preferably performed at a temperature of the melting point +100 ℃.

Manufacturing apparatus

In the process for producing a polyarylene sulfide resin according to the present invention, in terms of corrosion resistance, it is preferable that the reaction apparatus used in each step is a reaction apparatus in which a part or all of the contact portion with the raw material, that is, the dihalo-aromatic compound, the vulcanizing agent, the alkali catalyst, or the like, the aliphatic cyclic compound which can be ring-opened by hydrolysis, the mixture obtained through the dehydration step, and the polymerization product containing the polyarylene sulfide resin obtained after the polymerization reaction is made of titanium, zirconium, or a nickel alloy.

Examples of the reaction apparatus include a batch reaction vessel (autoclave, reaction vessel) having a stirring blade therein, a reaction vessel (polymerization line) such as a continuous reaction vessel, a stirring blade, and a baffle plate.

For example, the batch reactor may be a vessel capable of holding the raw materials, mixture or polymerization reaction product inside the reactor, and examples thereof include those having a structure comprising an upper lid part, a body part and a bottom part and being sealable as required, and those having an agitating blade positioned inside, a shaft for transmitting power to the agitating blade, a baffle plate (baffle) and a temperature control coil are preferable from the viewpoint of excellent agitation efficiency. Here, examples of the stirring blade include an anchor type stirring blade, a turbine type stirring blade, a screw type stirring blade, a double screw type stirring blade, and the like. From the viewpoint of facilitating heat conduction and heat control, the baffle plate (pocket) is preferably arranged such that the lower end reaches the vicinity of the bottom surface of the reaction vessel and the upper end reaches a position exposed from the liquid surface.

On the other hand, examples of the continuous reaction vessel include: the tubular reactor in which a plurality of mixing elements having no movable portion are fixed inside includes: a polymerization line in which the tubular reactors are connected in series, or a continuous loop polymerization line in which a plurality of tubular reactors are connected and a part of the reaction solution is circulated through the raw material inlet of the tubular reactor. These continuous reaction vessels can be supplied with raw materials and transferred with reaction liquid by a plunger pump or the like.

The reaction vessel is preferably provided with various measuring devices such as a thermometer, a pressure gauge, and a safety valve, and is preferably provided with a distillation apparatus such as a pipe, an on-off valve, a condenser, a decanter, a distillate (organic layer component of the decanter) return line, a distillate (aqueous layer component of the decanter) distillation removal line, and a pressure reducing device such as a pressure regulating valve, a vacuum pump, and a hydrogen sulfide capturing device, which communicate with the vapor apparatus from the outside thereof.

In the reaction device used in the present invention, at least a part of the contact portion may preferably be entirely made of the nickel alloy. Here, from the viewpoint of corrosion resistance, the nickel alloy used is an alloy in which the content of chromium is preferably in the range of 43 mass% or more and 47 mass% or less, the content of molybdenum is in the range of 0.1 mass% or more and 2 mass% or less, and the balance is nickel and unavoidable impurities. Tungsten, iron, cobalt and copper are preferably contained in amounts of detection limits or less. In the present invention, the term "inevitable impurities" refers to a trace amount of impurities that are technically difficult to remove. In the present invention, for example, carbon atoms contained in the alloy at a ratio of 3% by mass or less, preferably 1% by mass or less, and more preferably at a detection limit or less may be mentioned.

Shaping and the like

The polyarylene sulfide resin obtained by the production method of the present invention described in detail above can be formed into a polyarylene sulfide resin composition through the following steps: the polyarylene sulfide resin is compounded with at least 1 other component selected from the group consisting of a filler, a thermoplastic resin other than the polyarylene sulfide resin, an elastomer, a crosslinkable resin having 2 or more functional groups, and a silane coupling agent, heated to a temperature not lower than the melting point of the polyarylene sulfide resin, and melt-kneaded.

The filler is not particularly limited, and examples thereof include fibrous fillers and inorganic fillers. As the fibrous filler, glass fiber, carbon fiber, silane glass fiber, ceramic fiber, aramid fiber, metal fiber, potassium titanate, silicon carbide, calcium sulfate, calcium silicate, and other fibers, wollastonite, and other natural fibers can be used. Further, as the inorganic filler, barium sulfate, calcium sulfate, clay, pyrophyllite, bentonite, sericite, zeolite, mica (マイカ), mica (yunmu), talc, attapulgite (attapulgite), ferrite, calcium silicate, calcium carbonate, magnesium carbonate, glass beads, and the like can be used. In addition, various additives such as a mold release agent, a colorant, a heat stabilizer, an ultraviolet stabilizer, a foaming agent, a rust preventive, a flame retardant, and a lubricant may be contained as the additives during molding.

Further, as the thermoplastic resin other than the polyarylene sulfide resin to be blended in the polyarylene sulfide resin composition of the present invention, a polyarylene sulfide resin composition in which synthetic resins such as polyester, polyamide, polyimide, polyetherimide, polycarbonate, polyphenylene ether, polysulfone, polyethersulfone, polyetheretherketone, polyetherketone, polyarylene, polyethylene, polypropylene, polytetrafluoroethylene, polyvinylidene fluoride, polystyrene, ABS resin, epoxy resin, silicone resin, phenol resin, polyurethane resin, liquid crystal polymer and the like are blended may be used. The blending ratio of the thermoplastic resin other than the polyarylene sulfide resin is preferably 1 part by mass or more, more preferably 3 parts by mass or more, further preferably 5 parts by mass or more to preferably 300 parts by mass or less, more preferably 100 parts by mass or less, further preferably 45 parts by mass or less, with respect to 100 parts by mass of the polyarylene sulfide resin. The content of the thermoplastic resin other than the polyarylene sulfide resin is in these ranges, whereby the effects of further improving heat resistance, chemical resistance and mechanical properties can be obtained.

As the elastomer to be blended in the polyarylene sulfide resin composition of the present invention, a thermoplastic elastomer can be used. Examples of the thermoplastic elastomer include polyolefin elastomers, fluorine elastomers, and silicone elastomers. In the present specification, the thermoplastic elastomer is classified as an elastomer instead of the aforementioned thermoplastic resin.

The elastomer (particularly, the thermoplastic elastomer) preferably has a functional group capable of reacting with a hydroxyl group or an amino group, and thus a resin composition particularly excellent in adhesion, impact resistance and the like can be obtained, and examples of the functional group include a group represented by an epoxy group, a carboxyl group, an isocyanate group, an oxazoline group, and a group represented by the formula R (CO) O (CO) -or R (CO) O- (wherein R represents an alkyl group having 1 to 8 carbon atoms), and the thermoplastic elastomer having the functional group can be obtained by, for example, copolymerizing α -olefin with a vinyl polymerizable compound having the functional group, and α -olefin having 2 to 8 carbon atoms such as ethylene, propylene and 1-butene, and α -olefin, and vinyl polymerizable compounds having the functional group include, for example, α -unsaturated carboxylic acids such as (meth) propionic acid and (meth) propionic acid ester, and alkyl esters thereof, maleic acid, fumaric acid, itaconic acid, and other unsaturated dicarboxylic acids having 4 to 10 carbon atoms and derivatives thereof (monoesters or diesters thereof, anhydrides thereof, and copolymers thereof, and ethylene-acrylic acid copolymers having at least one or more of the group represented by the formula R (CO) and ethylene-acrylate, and the group represented by the formula R- (CO) and copolymers having a carbon atom number of (CO), (preferably, and the formula R-ethylene-acrylate group, and the formula R-1-ethylene-acrylate group, and the group represented by the formula (CO).

The blending ratio of the elastomer varies depending on the kind and the use thereof, and therefore cannot be generally specified, and for example, it is preferably 1 part by mass or more, more preferably 3 parts by mass or more, further preferably 5 parts by mass or more to preferably 300 parts by mass or less, more preferably 100 parts by mass or less, and further preferably 45 parts by mass or less with respect to 100 parts by mass of the polyarylene sulfide resin. When the content of the elastomer is in these ranges, a further excellent effect can be obtained in terms of ensuring the heat resistance and toughness of the molded article.

The crosslinkable resin blended in the polyarylene sulfide resin composition has 2 or more functional groups. Examples of the functional group include an epoxy group, a phenolic hydroxyl group, an amino group, an amide group, a carboxyl group, an acid anhydride group, and an isocyanate group. Examples of the crosslinkable resin include an epoxy resin, a phenol resin, and a urethane resin.

The amount of the crosslinkable resin to be blended is preferably 1 part by mass or more, more preferably 3 parts by mass or more, and further preferably 5 parts by mass or more to preferably 300 parts by mass or less, more preferably 100 parts by mass or less, and further preferably 30 parts by mass or less, based on 100 parts by mass of the polyarylene sulfide resin. When the amount of the crosslinkable resin is in these ranges, the effect of improving the rigidity and heat resistance of the molded article can be particularly remarkably obtained.

Examples of the silane coupling agent to be blended in the polyarylene sulfide resin composition of the present invention include γ -glycidoxypropyltrimethoxysilane, γ -glycidoxypropyltriethoxysilane, β - (3, 4-epoxycyclohexyl) ethyltrimethoxysilane, γ -glycidoxypropylmethyldiethoxysilane, and γ -glycidoxypropylmethyldimethoxysilane.

The amount of the silane compound to be blended is, for example, preferably in the range of 0.01 part by mass or more, more preferably 0.1 part by mass or more to preferably 10 parts by mass or less, more preferably 5 parts by mass or less, per 100 parts by mass of the polyarylene sulfide resin. The amount of the silane compound blended is in these ranges, whereby the effect of improving the compatibility of the polyarylene sulfide resin with the other components described above can be obtained.

The polyarylene sulfide resin composition of the present invention may further contain other additives such as a mold release agent, a colorant, a heat-resistant stabilizer, an ultraviolet stabilizer, a foaming agent, a rust preventive, a flame retardant, and a lubricant. The amount of the additive to be blended is preferably in the range of 1 part by mass or more and 10 parts by mass or less, for example, relative to 100 parts by mass of the polyarylene sulfide resin.

The polyarylene sulfide resin composition can be obtained in the form of, for example, a pellet-like mixture by a method of melt-kneading the polyarylene sulfide resin obtained by the above-described method and the other components. The temperature for melt kneading is, for example, preferably 250 ℃ or higher, more preferably 290 ℃ or higher to 350 ℃ or lower, and still more preferably 330 ℃ or lower. The melt kneading may be performed by using a twin-screw extruder or the like.

The polyarylene sulfide resin composition of the present embodiment can be processed into a molded article having excellent heat resistance, molding processability, dimensional stability, and the like by melt molding by various melt processing methods such as injection molding, extrusion molding, compression molding, blow molding, and the like, using alone or in combination with the above-described materials such as other components. The polyarylene sulfide resin composition of the present invention has a low metal content, and therefore, a high-quality molded article, particularly a thin-walled molded article having excellent insulation properties can be easily produced.

The polyarylene sulfide resin obtained by the production method of the present invention and the composition thereof have various properties such as heat resistance and dimensional stability which are inherent in polyarylene sulfide resins, and therefore, are widely useful as materials for various molding processes such as injection molding or compression molding, extrusion molding, or drawing of, for example, electrical and electronic parts such as connectors, printed boards, and sealing molded articles, automobile parts such as lamp reflectors and various electrical equipment parts, interior materials for various buildings, aircrafts, and automobiles, or precision parts such as OA equipment parts, camera parts, and watch parts, or as materials for fibers or films.