Polyarylene sulfide copolymer, method for producing the same, and polyarylene sulfide copolymer composition

Abstract

To provide a polyarylene sulfide copolymer that balances a high glass transition point with a high crystallization temperature, and a polyarylene sulfide copolymer composition that balances a high glass transition point with a high crystallization temperature.SOLUTION: A polyarylene sulfide copolymer includes an arylene sulfide unit with a number average molecular weight Mn of 1,000 or more and 10,000 or less, as a structural unit, with the arylene sulfide unit linked to a copolymerization component via an imide group. The polyarylene sulfide copolymer has a glass transition point of 95°C or higher and 190°C or lower by differential scanning calorimetry, while having a crystallization temperature of 165°C or higher.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a polyarylene sulfide copolymer. [Background technology]

[0002] Polyarylene sulfides, typified by polyphenylene sulfide (hereinafter sometimes abbreviated as PPS), have properties suitable for engineering plastics, such as excellent heat resistance, barrier properties, moldability, chemical resistance, electrical insulation, and moist heat resistance, and are used primarily in injection molding and extrusion molding for a variety of electrical and electronic parts, machine parts, automotive parts, films, fibers, etc. Due to their excellent properties, the range of applications for polyarylene sulfides has been expanding in recent years.

[0003] PPS, a typical polyarylene sulfide, is a crystalline polymer that generally has a glass transition point of 80-90°C and a melting point of 275-285°C, and is often used under high-temperature conditions due to its excellent heat resistance. PPS also dissolves in a very limited number of solvents only at high temperatures of 200-250°C, and is widely used in applications that take advantage of its excellent chemical resistance.

[0004] The aforementioned PPS, a typical example of polyarylene sulfide, has a high melting point and can withstand use at high temperatures. However, it suffers from the problem that its rigidity drops sharply at temperatures above its glass transition point of 80 to 90°C compared to temperatures below that point. Therefore, various studies have been conducted to improve the glass transition point of polyarylene sulfide.

[0005] For example, Patent Documents 1 and 2 disclose polyarylene sulfide copolymers obtained by reacting polyarylene sulfide having a reactive functional group with rigid molecules.

[0006] Patent Document 3 discloses a crystalline polyimide containing cumulative phenylene sulfide units in which dimer to nonamer phenylene sulfides and arylene groups are linked by imide bonds to improve the glass transition temperature.

[0007] Patent Document 4 discloses a copolymer comprising a polyarylene sulfide block and a polyetherimide block or a polydiorganosiloxane block.

[0008] Patent Document 5 discloses an aromatic imide sulfide polymer.

[0009] Patent Document 6 discloses a polyarylene sulfide-polyimide copolymer. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] International Publication No. 2019 / 151288 [Patent Document 2] International Publication No. 2022 / 045105 [Patent Document 3] Japanese Patent Application Publication No. 62-84124 [Patent Document 4] Japanese Patent Application Publication No. 64-45433 [Patent Document 5] Japanese Patent Application Publication No. 5-194738 [Patent Document 6] Japanese Patent Application Publication No. 4-220462 Summary of the Invention [Problem to be solved by the invention]

[0011] The polyarylene sulfide copolymers disclosed in Patent Documents 1 and 2 have a high glass transition point, but have a problem of poor crystallinity, such as a low crystallization temperature or no crystallization temperature. Furthermore, Patent Document 2 describes a reduction in the amount of gas generated during copolymer production and the associated efficiency of production, but neither Patent Document 1 nor 2 describes crystallinity or how to improve crystallinity.

[0012] The crystalline polyimide disclosed in Patent Document 3 has an improved glass transition point, but has the problem that the molecular weight of the phenylene sulfide unit is small and crystallization is slow.

[0013] Although the copolymer disclosed in Patent Document 4 also has an improved glass transition point, it has a problem in that it crystallizes slowly because it has a polyetherimide block or a polydiorganosiloxane block as a block structure.

[0014] The aromatic imide sulfide polymer disclosed in Patent Document 5 has an improved glass transition point, but it is difficult to obtain an aromatic imide sulfide polymer having a sufficient molecular weight of the arylene sulfide unit, and has a problem in that crystallization is slow.

[0015] The polyarylene sulfide-polyimide copolymer disclosed in Patent Document 6 can also improve the glass transition temperature by melt-blending polyimide, but has the problem of slow crystallization due to the influence of the melt-blended polyimide. In addition, the copolymer may contain free polyarylene sulfide and polyimide, making it difficult to achieve high crystallinity, including stability.

[0016] Furthermore, none of Patent Documents 3 to 6 includes any description regarding crystallinity or improving crystallinity.

[0017] Therefore, an object of the present invention is to obtain a polyarylene sulfide copolymer that has both a high glass transition point and a high crystallization temperature. [Means for solving the problem]

[0018] The present invention has been made to solve at least part of the above-mentioned problems, and can be realized by providing the following contents. 1. A polyarylene sulfide copolymer characterized by having, as a structural unit, an arylene sulfide unit having a number average molecular weight Mn of 1,000 or more and 10,000 or less, having a structure in which the arylene sulfide unit and a copolymerization component are linked by an imide group, having a glass transition point measured by differential scanning calorimetry of 95°C or more and 190°C or less, and having a crystallization temperature of 165°C or more. 2. 1901 cm originating from the benzene ring of the arylene sulfide unit -1 The absorption intensity at 3382 cm originating from the amino group -1 The specific intensity of absorption at 1860cm originating from acid anhydride groups is 0.11 or more and 0.90 or less. -1 2. The polyarylene sulfide copolymer according to 1 above, characterized in that the specific absorption intensity in .beta. 3. The polyarylene sulfide copolymer according to 1 or 2 above, which has at least one structure selected from the following formulae (a) to (s) as a structural unit:

[0019] [ka]

[0020] (R, R 1 , and R 2 is a substituent selected from hydrogen, an alkyl group having 1 to 12 carbon atoms, an arylene group having 6 to 24 carbon atoms, and a halogen group; R, R 1 , and R 2 may be the same or different.) 4. The polyarylene sulfide copolymer according to any one of 1 to 3 above, which has a melting point of 300° C. or less. 5. A method for producing a polyarylene sulfide copolymer according to any one of 1 to 4 above, which comprises heating a polyarylene sulfide (A) having a number average molecular weight Mn of 1,000 or more and 10,000 or less, and at least one compound (B) selected from the following formulae (a') to (u'), wherein the ratio of the total amount of half of the carboxyl groups and acid anhydride groups to the total amount of amino groups in the polyarylene sulfide (A) and compound (B) is 0.75 or more and 0.97 or less, or 1.03 or more and 1.25 or less:

[0021] [ka]

[0022] (X is either two carboxyl groups bonded to two adjacent carbon atoms, or an acid anhydride group derived from the two carboxyl groups, or an amino group; R, R 1 , and R 2 is a substituent selected from hydrogen, an alkyl group having 1 to 12 carbon atoms, an arylene group having 6 to 24 carbon atoms, and a halogen group; R, R 1 , and R 2 may be the same or different. The aromatic ring of each compound may be di- or tri-substituted, and the multiple substituents X substituted on one aromatic ring may be the same or different. 6. A method for producing a polyarylene sulfide copolymer according to 5 above, comprising mixing and heating at least a portion of the polyarylene sulfide (A) and at least a portion of at least one compound (B) selected from the following formulae (a') to (u'), and then mixing and heating the remaining polyarylene sulfide (A) and / or compound (B):

[0023] [ka]

[0024] (X is either two carboxyl groups bonded to two adjacent carbon atoms, or an acid anhydride group derived from the two carboxyl groups, or an amino group; R, R 1 , and R 2 is a substituent selected from hydrogen, an alkyl group having 1 to 12 carbon atoms, an arylene group having 6 to 24 carbon atoms, and a halogen group; R, R 1 , and R 2 may be the same or different. The aromatic ring of each compound may be di- or tri-substituted, and the multiple substituents X substituted on one aromatic ring may be the same or different. 7. The method for producing a polyarylene sulfide copolymer according to 5 or 6 above, wherein the heating is carried out substantially in the absence of a solvent. 8. A polyarylene sulfide copolymer composition comprising a polyarylene sulfide copolymer (C) having, as structural units, arylene sulfide units having a number average molecular weight Mn of 1,000 or more and 10,000 or less, in which the arylene sulfide units and copolymerization components are linked via imide groups, and a crystal nucleating agent, and having a glass transition point of 95°C or more and 190°C or less, and a crystallization temperature of 165°C or more, as measured by differential scanning calorimetry. 9. The polyarylene sulfide copolymer composition according to the above item 8, wherein the polyarylene sulfide copolymer (C) has, as a structural unit, at least one structure selected from the following formulae (a) to (s):

[0025] [ka]

[0026] (R, R 1 , and R 2 is a substituent selected from hydrogen, an alkyl group having 1 to 12 carbon atoms, an arylene group having 6 to 24 carbon atoms, and a halogen group; R, R 1 , and R 2 may be the same or different.) 10. The polyarylene sulfide copolymer composition according to 8 above, wherein at least a part of the polyarylene sulfide copolymer (C) is the polyarylene sulfide copolymer according to any one of 1 to 4 above. 11. A polyarylene sulfide copolymer composition containing the polyarylene sulfide copolymer according to any one of 1 to 4 above. 12. A molded article obtained by molding the polyarylene sulfide copolymer composition according to any one of 8 to 11 above. [Effects of the Invention]

[0027] According to the present invention, it is possible to provide a polyarylene sulfide copolymer having both a high glass transition point and a high crystallization temperature, and a polyarylene sulfide copolymer composition having both a high glass transition point and a high crystallization temperature. It is also possible to provide a method for producing the polyarylene sulfide copolymer from a polyarylene sulfide having a specific functional group and a reactive compound.

[0028] According to the present invention, polyarylene sulfide copolymers and polyarylene sulfide copolymer compositions (hereinafter sometimes referred to as resin compositions) having high crystallization temperatures can be obtained, which improves productivity by shortening the time cycle when molding these or when producing resin compositions containing fillers and / or other additives, and also improves and stabilizes the mechanical properties and chemical resistance of the resulting resin compositions by allowing sufficient crystallization. By achieving improved productivity and stabilized properties, it becomes possible to demonstrate stable performance under high-temperature conditions in applications such as electrical and electronic components, precision machinery-related components, plumbing parts, automotive and vehicle-related components, and aerospace-related components. DETAILED DESCRIPTION OF THE INVENTION

[0029] Hereinafter, embodiments of the present invention will be described in detail.

[0030] [Polyarylene sulfide copolymer] The lower limit of the glass transition point of the polyarylene sulfide copolymer is 95°C or higher, preferably 100°C or higher, and more preferably 110°C or higher. If the glass transition point is below 95°C, high rigidity cannot be obtained under high-temperature conditions. The upper limit of the glass transition point is 190°C or lower, preferably 180°C or lower, and more preferably 160°C or lower. If the glass transition point exceeds 190°C, the chemical resistance of the molded product will be insufficient. The glass transition point is defined as the inflection point of the baseline shift detected when the temperature is increased from 0°C to 340°C at a rate of 20°C / min using a differential scanning calorimeter.

[0031] The crystallization temperature of the polyarylene sulfide copolymer is 165°C or higher, preferably 170°C or higher, more preferably 180°C or higher, even more preferably 190°C or higher, and even more preferably 200°C or higher. A crystallization temperature below 165°C can result in insufficient crystallization speed during molding of the copolymer or during the production of a resin composition by blending the copolymer with a filler and / or other additives, as described below, resulting in reduced productivity and insufficient crystallization of the resulting resin composition, resulting in reduced mechanical properties and chemical resistance. While there is no particular upper limit for the crystallization temperature, a range of 235°C or lower is typically exemplified. The crystallization temperature is defined as the peak crystallization temperature detected when a differential scanning calorimeter is used to heat the sample from 0°C to 340°C at a rate of 20°C / min, hold the sample at 340°C for 1 minute, and then cool the sample to 100°C at a rate of 20°C / min.

[0032] The polyarylene sulfide copolymer preferably has a melting point of 300°C or lower. A melting point of 300°C or lower facilitates melt molding. The melting point is the melting peak temperature detected when the temperature is raised from 0°C to 340°C at a rate of 20°C / min using a differential scanning calorimeter, held at 340°C for 1 minute, cooled to 100°C at a rate of 20°C / min, held at 100°C for 1 minute, and then raised again to 340°C at a rate of 20°C / min. The melting point can be adjusted by selecting the molecular weight of the arylene sulfide unit in the polyarylene sulfide copolymer.

[0033] The polyarylene sulfide copolymer is a copolymer containing 70 mol % or more, preferably 80 mol % or more, of repeating units of the formula -(Ar-S)- as arylene sulfide units. Ar includes units represented by the following formulas (I) to (XI), among which the unit represented by formula (I) is particularly preferred.

[0034] [ka]

[0035] (R 3 ,R 4 is a substituent selected from hydrogen, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 24 carbon atoms, a halogen group, and a reactive functional group; R 3 and R 4 may be the same or different.) As long as this repeating unit is the main structural unit, it may contain a small amount of branching units or crosslinking units represented by the following formulas (XII) to (XIV), etc. The copolymerization amount of these branching units or crosslinking units is preferably in the range of 0 to 1 mol % per 1 mol of -(Ar-S)- units.

[0036] [ka]

[0037] (Here, Ar is a unit represented by the above formulas (I) to (XI).) The arylene sulfide unit may be any of a random copolymer, a block copolymer, and a mixture thereof containing the above repeating unit.

[0038] Representative examples of these include polyphenylene sulfide, polyphenylene sulfide sulfone, polyphenylene sulfide ketone, their random copolymers, block copolymers, and mixtures thereof. Particularly preferred polyarylene sulfides include those having a p-phenylene sulfide unit represented by the following formula (XV) as the main structural unit of the polymer:

[0039] [ka]

[0040] Examples of suitable polyphenylene sulfides include polyphenylene sulfides containing 80 mol % or more, particularly 90 mol % or more of the above.

[0041] The lower limit of the number average molecular weight of the arylene sulfide units is 1,000 or more, preferably 1,500 or more, and more preferably 2,000 or more. If the number average molecular weight of the arylene sulfide units is less than 1,000, the polyarylene sulfide copolymer will not have sufficient chemical resistance. The upper limit of the number average molecular weight of the arylene sulfide units is 10,000 or less, preferably 6,000 or less, and more preferably 4,000 or less. If the number average molecular weight of the arylene sulfide units is more than 10,000, the polyarylene sulfide copolymer will not have sufficient heat resistance. The number average molecular weight of the arylene sulfide units in the polyarylene sulfide copolymer can be determined, for example, by treating the polyarylene sulfide copolymer in a 10% aqueous sodium hydroxide solution under reflux conditions for 5 hours and then measuring the molecular weight of the residue. In order to set the number average molecular weight of the arylene sulfide units in the polyarylene sulfide copolymer within the above range, it is preferable to use, in the production of the polyarylene sulfide copolymer, a polyarylene sulfide (A) having a number average molecular weight Mn of 1,000 or more and 10,000 or less, as described below. The weight average molecular weight and number average molecular weight can be determined, for example, using SEC (size exclusion chromatography) equipped with a differential refractive index detector.

[0042] Examples of structures contained in the polyarylene sulfide copolymer as a copolymerization component include structures containing aromatic rings, preferably structures represented by the formulas (a) to (s), more preferably structures represented by the formulas (a) to (e), (i) and (j), and among these, the structure represented by the formula (i) is particularly preferred. By containing these structures, the crystallinity of the obtained polyarylene sulfide copolymer tends to be excellent.

[0043] In the polyarylene sulfide copolymer, the arylene sulfide units consisting of repeating units of -(Ar-S)- and the copolymerization components are linked by imide groups. Linkage by imide groups results in high rigidity at high temperatures. The lower limit of the imide group content is preferably 1 mol% or more, more preferably 2 mol% or more, and even more preferably 4 mol% or more, relative to the sulfur atoms in the polyarylene sulfide copolymer. By setting the content within the above range, it is likely that a decrease in rigidity under high-temperature conditions can be sufficiently suppressed. The upper limit of the imide group content is preferably 60 mol% or less, more preferably 40 mol% or less, even more preferably 30 mol% or less, and even more preferably 20 mol% or less. As the imide group content increases, the chemical resistance of the resulting polyarylene sulfide copolymer tends to decrease, but by setting the content within the above range, it is likely that a polyarylene sulfide copolymer exhibiting sufficient chemical resistance and mechanical properties can be obtained. The amount of imide groups can be calculated using the amount of functional groups contained in the polyarylene sulfide (A) used in the production of the polyarylene sulfide copolymer and the amount of functional groups contained in the compound (B), or can be determined using the FT-IR spectrum or NMR spectrum of the polyarylene sulfide copolymer.

[0044] The polyarylene sulfide copolymer preferably has a larger amount of either the amino group amount or the total amount of half the carboxyl group amount and the acid anhydride group amount. The amino group amount or the total amount of half the carboxyl group amount and the acid anhydride group amount can be determined by measuring the 1901 cm -ray spectroscopy derived from the benzene ring of the arylene sulfide unit using a Fourier transform infrared spectrophotometer (FT-IR). -1For FT-IR evaluation, it is preferable to use an amorphous film prepared by quenching from a molten state. -1 Specific intensity of absorption at 1860cm due to acid anhydride group -1 When evaluating the specific intensity of the absorption at 1901 cm , the melting temperature for preparing an amorphous film is 320 °C. -1 The absorption intensity at 3382 cm originating from the amino group -1 The lower limit of the specific intensity of absorption at 1901 cm is preferably 0.11 or more, more preferably 0.13 or more, even more preferably 0.15 or more, still more preferably 0.20 or more, and still more preferably 0.40 or more. -1 The absorption intensity at 1860cm originating from the acid anhydride group -1 The lower limit of the specific intensity of the absorption at 1860 cm derived from the acid anhydride group is preferably 0.20 or more, more preferably 0.30 or more, even more preferably 0.40 or more, still more preferably 0.50 or more, and still more preferably 1.0 or more. -1 The total amount of carboxyl groups and acid anhydride groups is evaluated by measuring the relative intensity of absorption at 1901 cm . Having a large amount of either the amino group amount or the total amount of half the carboxyl group amount and the acid anhydride group amount, as in the above range, increases the crystallization temperature of the polyarylene sulfide copolymer, and tends to result in excellent crystallinity. The reason for this is unclear, but it is thought that the presence of many similar structures in the copolymer makes it easier for the polymer ends and polymer chains to align. Meanwhile, from the perspective of the molecular weight of the polyarylene sulfide copolymer and the mechanical properties derived therefrom, the 1901 cm peak derived from the benzene rings of the arylene sulfide units is -1 The absorption intensity at 3382 cm originating from the amino group -1The upper limit of the specific intensity of absorption at 1901 cm derived from the benzene ring of the arylene sulfide unit is preferably 0.90 or less, more preferably 0.70 or less, and even more preferably 0.50 or less. -1 The absorption intensity at 1860cm originating from the acid anhydride group -1 The upper limit of the specific absorption intensity in is preferably 2.2 or less, more preferably 1.5 or less, even more preferably 1.0 or less, still more preferably 0.60 or less, and even more preferably 0.40 or less. Whether the amount of amino groups or the total amount of half of the amount of carboxyl groups and the amount of acid anhydride groups is greater can be selected depending on the reactivity and properties required of the polyarylene sulfide copolymer, the application and use environment of the polyarylene sulfide copolymer, and the types and structures of various fillers and other additives contained in a resin composition containing the polyarylene sulfide copolymer.

[0045] The lower limit of the molecular weight of the polyarylene sulfide copolymer is preferably 10,000 or more in weight average molecular weight, more preferably 20,000 or more, even more preferably 30,000 or more, and even more preferably 40,000 or more. When the lower limit of the weight average molecular weight is within the above range, the mechanical properties of the polyarylene sulfide copolymer tend to be excellent. There is no particular restriction on the upper limit of the weight average molecular weight, but examples include 200,000 or less, preferably 100,000 or less, and more preferably 80,000 or less. When the upper limit of the weight average molecular weight is within the above range, the moldability and crystallinity of the polyarylene sulfide copolymer tend to be excellent. The weight average molecular weight can be determined, for example, using SEC (size exclusion chromatography) equipped with a differential refractive index detector.

[0046] [Method for producing polyarylene sulfide copolymer] The polyarylene sulfide copolymer of the present invention is preferably produced by a method of heating a polyarylene sulfide (A) having a number-average molecular weight Mn of 1,000 to 10,000 and at least one compound (B) selected from formulas (a') to (u') (hereinafter sometimes abbreviated as compound (B)). In this case, the ratio of half of the amount of carboxyl groups and the total amount of acid anhydride groups to the total amount of amino groups in the polyarylene sulfide (A) and compound (B) is preferably 0.75 to 0.97, or 1.03 to 1.25. The polyarylene sulfide (A) and compound (B) will be described below.

[0047] [Polyarylene sulfide (A)] The polyarylene sulfide (A) is a homopolymer or copolymer having a repeating unit of the formula -(Ar-S)- as a main structural unit. Here, "main structural unit" means that the repeating unit accounts for 70 mol% or more. Ar includes units represented by the above formulas (I) to (XI), among which the unit represented by formula (I) is particularly preferred.

[0048] As long as this repeating unit is the main structural unit, it may contain a small amount of branching units or crosslinking units represented by the above formulas (XII) to (XIV), etc. The copolymerization amount of these branching units or crosslinking units is preferably in the range of 0 to 1 mol % per 1 mol of -(Ar-S)- units.

[0049] The polyarylene sulfide (A) may be any of a random copolymer, a block copolymer, and a mixture thereof containing the above repeating unit.

[0050] Representative examples of these include polyphenylene sulfide, polyphenylene sulfide sulfone, polyphenylene sulfide ketone, their random copolymers, block copolymers, and mixtures thereof. Particularly preferred polyarylene sulfides include polyphenylene sulfides containing 80 mol % or more, particularly 90 mol % or more, of p-phenylene sulfide units represented by the formula (XV) as the main structural unit of the polymer.

[0051] The polyarylene sulfide (A) contains at least one functional group selected from an amino group, two carboxyl groups bonded to adjacent carbon atoms, and an acid anhydride group derived from the two carboxyl groups. From the viewpoint of reactivity when the polyarylene sulfide (A) is heated with the compound (B) described below, the combination of the functional group of the polyarylene sulfide (A) and the functional group of the compound (B) is preferably an amino group and an acid anhydride group. Therefore, depending on the functional group of the compound (B), the functional group of the polyarylene sulfide (A) is preferably an amino group or an acid anhydride group. Furthermore, from the viewpoint of ease of polymerization reaction when producing the polyarylene sulfide (A) by the production method described below, the functional group of the polyarylene sulfide (A) is preferably an amino group, and accordingly, the functional group of the compound (B) is preferably an acid anhydride group. The position of the functional group may be in the main chain of the polyarylene sulfide or at the terminal, but terminal introduction is preferred because it is easier to control the reaction with other polymers or compounds having the functional group, and is also preferred from the viewpoint of copolymerization with compound (B), as described below. In the case of terminal introduction, the position is preferably p-position relative to the S bonded to Ar. Another preferred example is a polyarylene sulfide having the functional group bonded to the Ar. The functional group is a structure derived from compound (D), and details will be described later.

[0052] The lower limit of the amount of functional groups contained in the polyarylene sulfide (A) is preferably 400 μmol / g or more, more preferably 500 μmol / g or more, and even more preferably 700 μmol / g or more. Having the functional groups at or above the above lower limit is preferred because the glass transition temperature of the polyarylene sulfide copolymer tends to be sufficiently high. The upper limit of the amount of functional groups is preferably 5,000 μmol / g or less, more preferably 4,000 μmol / g or less, and even more preferably 3,000 μmol / g or less. Having the amount of functional groups at or below the above upper limit is preferred because it prevents a decrease in the chemical resistance of the polyarylene sulfide copolymer. When the functional groups are two carboxyl groups bonded to two adjacent carbon atoms, respectively, the functional groups refer to the amount of acid anhydride groups generated from the two carboxyl groups bonded to the two adjacent carbon atoms. The functional groups in polyarylene sulfide can be determined by FT-IR analysis of the polyarylene sulfide, for example, 1901m derived from the benzene ring. -1 Absorption at 3382cm originating from amino groups -1 The intensity of the absorption of 1901m from the benzene ring -1 The absorption at 1860cm originating from the acid anhydride group -1 The amount can be quantified by comparing the intensity of the absorption of

[0053] The number average molecular weight of the polyarylene sulfide (A) is 1,000 or more, preferably 2,000 or more. If the number average molecular weight of the polyarylene sulfide (A) is less than 1,000, the chemical resistance of the polyarylene sulfide copolymer will be insufficient. The upper limit of the number average molecular weight of the polyarylene sulfide (A) is 10,000 or less, preferably 6,000 or less, and more preferably 4,000 or less. If the number average molecular weight of the polyarylene sulfide exceeds 10,000, the heat resistance of the polyarylene sulfide copolymer and the polyarylene sulfide copolymer composition will be insufficient. The number average molecular weight is a value calculated in terms of polystyrene using gel permeation chromatography (GPC), a type of size exclusion chromatography (SEC).

[0054] The polyarylene sulfide (A) preferably has a weight loss rate of 5 wt% or less, more preferably 4 wt% or less, and even more preferably 3 wt% or less when heated from 30°C to 320°C at a temperature increase rate of 10°C / min. The smaller the weight loss rate, the better, and the lower limit can be exemplified as 0.01 wt% or more. When the example described below is used as a production method for polyarylene sulfide (A), even if a large amount of functional groups are introduced into polyarylene sulfide (A), components that tend to become gaseous components when heated tend not to remain.

[0055] The weight loss rate can be determined by standard thermogravimetric analysis. A non-oxidizing atmosphere at atmospheric pressure is typically used for this analysis. A non-oxidizing atmosphere refers to an atmosphere in which the oxygen concentration in the gas phase in contact with the sample is 5% by volume or less, preferably 2% by volume or less, and more preferably substantially oxygen-free. An inert gas atmosphere such as nitrogen, helium, or argon is preferred. Among these, a nitrogen atmosphere is particularly preferred from the standpoints of economy and ease of handling. Furthermore, atmospheric pressure refers to atmospheric pressure, i.e., a pressure condition of approximately 101.3 kPa absolute. Furthermore, to measure the weight loss rate, thermogravimetric analysis is performed by heating from room temperature to any temperature above 320°C at a rate of 10°C / min. This temperature range is frequently used for the practical use of polyarylene sulfides, such as polyphenylene sulfide, or for melting and molding or reacting them. The weight loss rate in this practical temperature range serves as an indicator of the amount of gas generated from polyarylene sulfide during practical use and the degree of contamination of equipment during molding, processing, and reactions. Therefore, a polyarylene sulfide having a small weight loss rate in such a temperature range can be said to be an excellent polyarylene sulfide of high quality.

[0056] Furthermore, when the example described later is used as a method for producing polyarylene sulfide (A), the crystallinity of the polyarylene sulfide copolymer obtained using the polyarylene sulfide (A) tends to be excellent, which is preferable. This is also thought to be because when polyarylene sulfide (A) is produced by the production method described later, components that tend to become gas components when heated are less likely to remain.

[0057] The method for producing polyarylene sulfide (A) of the present invention is specifically described below. Although not limited to the following method, the present invention is directed to a method for producing polyarylene sulfide by reacting at least a dihalogenated aromatic compound, an inorganic sulfidizing agent, and compound (D) in an organic polar solvent in the presence of an alkali metal hydroxide, preferably a method in which compound (D) is present in a reaction vessel in an amount of 0.04 to 0.5 moles per mole of inorganic sulfidizing agent. Here, compound (D) is a compound having at least one aromatic ring, and on the aromatic ring, an amino group, two carboxyl groups bonded to adjacent carbon atoms, respectively, at least one functional group selected from an acid anhydride group derived from the two carboxyl groups, and at least one functional group selected from a hydroxyl group, a salt of a hydroxyl group, a thiol group, and a salt of a thiol group. When such a production method is selected, functional group-containing polyarylene sulfide (A) with few impurities can be obtained, and the crystallization temperature of the polyarylene sulfide copolymer produced using it tends to be high.

[0058] Furthermore, when two carboxyl groups bonded to two adjacent carbon atoms or acid anhydride groups derived from these two carboxyl groups are selected as the functional groups contained in the polyarylene sulfide (A), it is also effective to employ a known method for producing polyarylene sulfide in which at least a dihalogenated aromatic compound, an inorganic sulfidizing agent, and a monohalogenated compound are reacted in an organic polar solvent in the presence of an alkali metal hydroxide, from the viewpoint of the reactivity of the monohalogenated compound, i.e., the ease of introducing functional groups into the polyarylene sulfide (A). Examples of the monohalogenated compound used here include 3-chlorophthalic acid and 4-chlorophthalic acid.

[0059] [Inorganic sulfidizing agent] The inorganic sulfidizing agent used in the production method of polyarylene sulfide (A) may be any agent capable of introducing a sulfide bond into a dihalogenated aromatic compound, and examples thereof include alkali metal sulfides, alkali metal hydrosulfides, and hydrogen sulfide.

[0060] Specific examples of alkali metal sulfides include lithium sulfide, sodium sulfide, potassium sulfide, rubidium sulfide, cesium sulfide, and mixtures of two or more of these. Of these, lithium sulfide and / or sodium sulfide are preferred, with sodium sulfide being more preferred. These alkali metal sulfides can be used as hydrates, aqueous mixtures, or anhydrous forms. An aqueous mixture refers to an aqueous solution, a mixture of an aqueous solution and a solid component, or a mixture of water and a solid component. Generally available, inexpensive alkali metal sulfides are hydrates or aqueous mixtures, so it is preferable to use alkali metal sulfides in these forms.

[0061] Specific examples of alkali metal hydrosulfides include lithium hydrosulfide, sodium hydrosulfide, potassium hydrosulfide, rubidium hydrosulfide, cesium hydrosulfide, and mixtures of two or more of these. Of these, lithium hydrosulfide and / or sodium hydrosulfide are preferred, and sodium hydrosulfide is more preferably used.

[0062] Alternatively, an alkali metal sulfide prepared in a reaction system from an alkali metal hydrosulfide and an alkali metal hydroxide can be used. Alternatively, an alkali metal sulfide prepared in advance by contacting an alkali metal hydrosulfide with an alkali metal hydroxide can be used. These alkali metal hydrosulfides and alkali metal hydroxides can be used as hydrates, aqueous mixtures, or anhydrous forms, with hydrates or aqueous mixtures being preferred from the standpoints of availability and cost.

[0063] Furthermore, alkali metal sulfides prepared in the reaction system from an alkali metal hydroxide such as lithium hydroxide or sodium hydroxide and hydrogen sulfide can also be used.Alkali metal sulfides prepared in advance by contacting an alkali metal hydroxide such as lithium hydroxide or sodium hydroxide with hydrogen sulfide can also be used.Hydrogen sulfide may be used in any form, whether gaseous, liquid, or aqueous solution.

[0064] [Compound (D)] The compound (D) used in the production method of polyarylene sulfide (A) is a compound having at least one aromatic ring and, on the aromatic ring, at least one functional group selected from an amino group, two carboxyl groups bonded to two adjacent carbon atoms, and an acid anhydride group derived from the two carboxyl groups, and at least one functional group selected from a hydroxyl group, a salt of a hydroxyl group, a thiol group, and a salt of a thiol group. Compound (D) may be any aromatic compound having a functional group selected from an amino group, two carboxyl groups bonded to two adjacent carbon atoms, and an acid anhydride group derived from the two carboxyl groups, which is introduced as a functional group into polyarylene sulfide, and a hydroxyl group, a salt of a hydroxyl group, a thiol group, or a salt of a thiol group that reacts with a dihalogenated aromatic compound in the polymerization reaction step described below. Specific examples of preferred compounds include 2-aminophenol, 4-aminophenol, 3-aminophenol, 2-aminothiophenol, 4-aminothiophenol, 3-aminothiophenol, 3-hydroxyphthalic acid, 4-hydroxyphthalic acid, 3-mercaptophthalic acid, 4-mercaptophthalic acid, and compounds in which the hydroxyl or thiol group of these compounds is a salt with an alkali metal or alkaline earth metal. From the viewpoint of reactivity, 4-aminophenol and 4-aminothiophenol are particularly preferred compounds. Two or more different compounds (D) can be used in combination as long as they have the above characteristics. When using a compound having a hydroxyl or thiol group as compound (D), a preferred embodiment is to simultaneously use an equal amount of alkali metal hydroxide. Furthermore, when using a compound in which the hydroxyl or thiol group is in the form of a salt as compound (D), the salt can be formed in advance before use in the production of polyarylene sulfide, or the salt can be formed during the reaction in a reaction vessel.

[0065] The lower limit of the amount of compound (D) used is 0.04 mol or more, preferably 0.05 mol or more, more preferably 0.06 mol or more, even more preferably 0.08 mol or more, and even more preferably 0.1 mol or more, per mol of the inorganic sulfidizing agent added. A use amount of this value or more is preferred because it allows sufficient introduction of amino groups into the polyarylene sulfide. The upper limit of the amount of compound (D) used is 0.5 mol or less, more preferably 0.45 mol or less, and even more preferably 0.4 mol or less, per mol of the inorganic sulfidizing agent added. A use amount of this value or less is preferred because it prevents a decrease in the molecular weight of the polyarylene sulfide and a decrease in its mechanical properties.

[0066] The timing of adding compound (D) is not particularly specified, and compound (D) may be added at any time during the pre-processing step described below, at the start of polymerization, or during the polymerization reaction step, or may be added in multiple batches. However, from the viewpoint of efficiently reacting compound (D) with the dihalogenated aromatic compound, it is more preferable to add compound (D) at the same stage as the addition of the dihalogenated aromatic compound to the reaction vessel.

[0067] [Dihalogenated aromatic compound] Examples of dihalogenated aromatic compounds used in the production method of polyarylene sulfide (A) include dihalogenated benzenes such as p-dichlorobenzene, o-dichlorobenzene, m-dichlorobenzene, p-dibromobenzene, o-dibromobenzene, m-dibromobenzene, 1-bromo-4-chlorobenzene, and 1-bromo-3-chlorobenzene, as well as dihalogenated aromatic compounds including compounds having substituents other than halogen, such as 1-methoxy-2,5-dichlorobenzene, 1-methyl-2,5-dichlorobenzene, 1,4-dimethyl-2,5-dichlorobenzene, 1,3-dimethyl-2,5-dichlorobenzene, 2,5-dichlorobenzoic acid, 3,5-dichlorobenzoic acid, 2,5-dichloroaniline, 3,5-dichloroaniline, and bis(4-chlorophenyl)sulfide. Among these, dihalogenated aromatic compounds mainly composed of p-dihalogenated benzenes, such as p-dichlorobenzene, are preferred. Particularly preferably, it contains 80 to 100 mol % of p-dichlorobenzene, and further preferably 90 to 100 mol %. It is also possible to use a combination of two or more different dihalogenated aromatic compounds.

[0068] Although there is no particular lower limit to the amount of dihalogenated aromatic compound used, the [monomer ratio] expressed by the following formula is preferably 0.8 or more, more preferably 0.9 or more, and even more preferably 0.95 or more. By setting the [monomer ratio] within the above range, the polymerization reaction system can be stabilized and side reactions can be prevented, which is preferable. Furthermore, there is no particular upper limit to the amount used, but the [monomer ratio] is preferably 1.2 or less, more preferably 1.1 or less, and even more preferably 1.05 or less. By setting the [monomer ratio] within the above range, the amount of halogen remaining in the polyarylene sulfide can be reduced, which is preferable. In the following formula, the [dihalogenated aromatic compound substance amount], [inorganic sulfidizing agent substance amount], and [compound (D) substance amount] indicate the amount of each compound used when producing polyarylene sulfide. [Monomer ratio] = [Amount of dihalogenated aromatic compound] / ([Amount of inorganic sulfidizing agent] + [Amount of compound (D)])

[0069] [Organic polar solvents] Preferred examples of organic polar solvents used in the polyarylene sulfide production method of the present invention include organic amide solvents. Specific examples include N-alkylpyrrolidones such as N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, and N-cyclohexyl-2-pyrrolidone, caprolactams such as N-methyl-ε-caprolactam, aprotic organic solvents such as 1,3-dimethyl-2-imidazolidinone, N,N-dimethylacetamide, N,N-dimethylformamide, and hexamethylphosphoric triamide, and mixtures thereof, which are preferably used due to their high reaction stability. Among these, N-methyl-2-pyrrolidone and 1,3-dimethyl-2-imidazolidinone are preferred, and N-methyl-2-pyrrolidone is more preferred.

[0070] The amount of organic polar solvent used is preferably 2.0 mol or more, more preferably 2.2 mol or more, and even more preferably 2.3 mol or more, per mol of inorganic sulfidizing agent charged. A use amount of this value or more is preferred because polyarylene sulfide can be synthesized in good yield. Furthermore, the amount of organic polar solvent used is preferably 6.0 mol or less, more preferably 5.0 mol or less, and even more preferably 4.0 mol or less, per mol of inorganic sulfidizing agent charged. A use amount of this value or less is preferred because gas generation upon heating of the resulting polyarylene sulfide can be reduced.

[0071] [Polymerization aid] In one preferred embodiment, a polymerization aid is used to obtain a polyarylene sulfide with a relatively high degree of polymerization in a shorter time. Here, the polymerization aid refers to a substance that has the effect of increasing the viscosity of the resulting polyarylene sulfide. Specific examples of such polymerization aids include organic carboxylates, water, alkali metal chlorides, organic sulfonates, alkali metal sulfates, alkaline earth metal oxides, alkali metal phosphates, and alkaline earth metal phosphates. These may be used alone or in combination of two or more. Among these, organic carboxylates, water, and alkali metal chlorides are preferred, with alkali metal carboxylates being preferred as the organic carboxylates and lithium chloride being preferred as the alkali metal chlorides.

[0072] The alkali metal carboxylate is represented by the general formula R(COOM) n (wherein R is an alkyl group, cycloalkyl group, aryl group, alkylaryl group, or arylalkyl group having 1 to 20 carbon atoms; M is an alkali metal selected from lithium, sodium, potassium, rubidium, and cesium; and n is an integer of 1 to 3.) The alkali metal carboxylate can also be used as a hydrate, anhydrous form, or aqueous solution. Specific examples of the alkali metal carboxylate include lithium acetate, sodium acetate, potassium acetate, sodium propionate, lithium valerate, sodium benzoate, and mixtures thereof.

[0073] Alkali metal carboxylates may be synthesized by adding and reacting an organic acid with one or more compounds selected from the group consisting of alkali metal hydroxides, alkali metal carbonates, and alkali metal bicarbonates in approximately equal chemical equivalents. Among the alkali metal carboxylates, lithium salts are highly soluble in the reaction system and have a significant auxiliary effect, but are expensive. On the other hand, potassium, rubidium, and cesium salts are thought to have insufficient solubility in the reaction system, so sodium acetate, which is inexpensive and has adequate solubility in the polymerization system, is most preferably used.

[0074] When these alkali metal carboxylates are used as polymerization aids, the amount used is usually in the range of 0.01 mol to 2 mol per mol of the charged inorganic sulfidizing agent, and in terms of obtaining a higher degree of polymerization, the range of 0.1 mol to 0.6 mol is preferred, and the range of 0.2 mol to 0.5 mol is more preferred.

[0075] When water is used as a polymerization aid, the amount added is usually in the range of 0.3 mol to 15 mol per mol of the charged inorganic sulfidizing agent, and in terms of obtaining a higher degree of polymerization, the range of 0.6 mol to 10 mol is preferred, and the range of 1 mol to 5 mol is more preferred.

[0076] Of course, two or more of these polymerization aids can be used in combination. For example, when an alkali metal carboxylate and water are used in combination, a higher molecular weight can be achieved with smaller amounts of the alkali metal carboxylate and water.

[0077] The timing of addition of these polymerization aids is not particularly specified, and they may be added at any time during the pre-step, at the start of polymerization, or during the polymerization reaction step, as described below, or may be added in multiple batches. When an alkali metal carboxylate is used as the polymerization aid, it is more preferable to add it simultaneously with other additives at the start of the pre-step or at the start of polymerization, from the viewpoint of ease of addition. Furthermore, when water is used as the polymerization aid, it is effective to add it during the polymerization reaction step after charging the dihalogenated aromatic compound.

[0078] [Polymerization stabilizer] Polymerization stabilizers can be used to stabilize the polymerization reaction system and prevent side reactions. Polymerization stabilizers contribute to stabilizing the polymerization reaction system and suppress undesirable side reactions. One indicator of side reactions is the formation of thiophenol. The addition of a polymerization stabilizer can suppress the formation of thiophenol. Specific examples of polymerization stabilizers include compounds such as alkali metal hydroxides, alkali metal carbonates, alkaline earth metal hydroxides, and alkaline earth metal carbonates. Among these, alkali metal hydroxides such as sodium hydroxide, potassium hydroxide, and lithium hydroxide are preferred. The aforementioned alkali metal carboxylates also function as polymerization stabilizers and are therefore classified as polymerization stabilizers. Furthermore, when using alkali metal hydrosulfides as inorganic sulfidizing agents, it is particularly preferable to use alkali metal hydroxides simultaneously. However, alkali metal hydroxides in excess of the sulfidizing agent can also function as polymerization stabilizers.

[0079] These polymerization stabilizers can be used alone or in combination of two or more. The polymerization stabilizer is preferably used in a proportion of usually 0.02 mol to 0.2 mol, preferably 0.03 mol to 0.1 mol, more preferably 0.04 mol to 0.09 mol, per mol of the charged inorganic sulfidizing agent. If this proportion is too small, the stabilizing effect is insufficient, and conversely, if it is too large, it is economically disadvantageous and the polymer yield tends to decrease.

[0080] The timing of adding the polymerization stabilizer is not particularly specified, and it may be added at any time during the pre-step, at the start of polymerization, or during the polymerization reaction step described below, or may be added in multiple divided portions, but it is more preferable to add it simultaneously at the start of the pre-step or at the start of polymerization from the viewpoint of ease.

[0081] Next, a preferred method for producing the polyarylene sulfide of the present invention will be specifically explained in order, including the pre-process, polymerization reaction process, recovery process, and post-treatment process, but the method is not limited to this method.

[0082] [Pre-process] In the method for producing the polyarylene sulfide (A), the inorganic sulfidizing agent is usually used in the form of a hydrate. However, it is preferable to heat the mixture containing the organic polar solvent and the inorganic sulfidizing agent and remove excess water from the system before adding the dihalogenated aromatic compound.

[0083] As mentioned above, inorganic sulfidizing agents can also be used that are prepared in situ in the reaction system or in a separate vessel from the polymerization vessel from an alkali metal hydrosulfide and an alkali metal hydroxide. While there are no particular limitations on this method, a preferred method involves adding an alkali metal hydrosulfide and an alkali metal hydroxide to an organic polar solvent under an inert gas atmosphere at room temperature to 150°C, preferably room temperature to 100°C, and then heating the mixture to at least 150°C or higher, preferably 180°C to 260°C, under atmospheric or reduced pressure, to distill off water. At this stage, a polymerization aid or compound (D) may be added. Toluene or the like may be added to facilitate the distillation of water during the reaction.

[0084] At the end of the pre-step, i.e., before the polymerization reaction step, the amount of water in the system is preferably 0.3 to 10.0 moles per mole of the charged sulfidizing agent. Here, the amount of water in the system is the amount of water charged into the polymerization system minus the amount of water removed from the polymerization system. The charged water may be in any form, such as water, an aqueous solution, or water of crystallization.

[0085] [Polymerization reaction process] Polyarylene sulfide (A) is produced by reacting at least an inorganic sulfidizing agent, a dihalogenated aromatic compound, and compound (D) in an organic polar solvent within a temperature range of 200°C or higher and lower than 290°C.

[0086] To start the polymerization reaction, an organic polar solvent, a sulfidizing agent, and a dihalogenated aromatic compound are mixed, preferably in an inert gas atmosphere, at a temperature ranging from room temperature to 240°C, and preferably from 100°C to 230°C. Compound (D) and a polymerization aid may be added at this stage. These raw materials may be added in any order, or simultaneously.

[0087] The mixture is usually heated to a temperature in the range of 200° C. to less than 290° C. There are no particular restrictions on the temperature increase rate, but a rate of 0.01° C. / min to 5° C. / min is usually selected, and a range of 0.1° C. / min to 3° C. / min is more preferred.

[0088] In general, the temperature is finally raised to 250° C. to less than 290° C., and the reaction is carried out at that temperature for usually 0.25 to 50 hours, preferably 0.5 to 20 hours.

[0089] A method of reacting at 200° C. to 260° C. for a certain period of time before reaching the final temperature, and then raising the temperature to 270° C. to less than 290° C., is effective in obtaining a higher degree of polymerization. In this case, the reaction time at 200° C. to 260° C. is usually selected from the range of 0.25 to 20 hours, and preferably from the range of 0.25 to 10 hours.

[0090] In order to adjust the molecular weight of the polymer, it is possible to add compound (D) during the polymerization. However, from the viewpoint of efficient reaction of compound (D), it is more preferable to add at least a part of compound (D) at the same stage as the dihalogenated aromatic compound.

[0091] [Recovery process] In the method for producing the polyarylene sulfide (A), after the polymerization is completed, a solid is recovered from the polymerization reaction product containing the polymer, the solvent, etc. Any known recovery method may be used.

[0092] For example, after the polymerization reaction is completed, the polymer may be slowly cooled and recovered in particulate form. The cooling rate is not particularly limited, but is typically about 0.1°C / min to 3°C / min. It is not necessary to cool at the same rate throughout the entire cooling process; instead, the polymer may be slowly cooled at a rate of 0.1°C / min to 1°C / min until the polymer particles crystallize and precipitate, and then at a rate of 1°C / min or faster.

[0093] Another preferred method is to carry out the above recovery under rapid cooling conditions. Among these recovery methods, a flash method is preferred. In the flash method, the polymerization reaction product is subjected to high temperature and high pressure (usually 250°C or higher, 8 kg / cm 2 This method involves flashing the polymer from the above-mentioned state into an atmosphere under normal pressure or reduced pressure, recovering the solvent and simultaneously recovering the polymer in powder form. The term "flashing" used here means ejecting the polymerization product from a nozzle. The flashing atmosphere can be specifically nitrogen or water vapor under normal pressure, and the temperature is usually selected within the range of 150°C to 250°C.

[0094] [Post-processing process] After the polyarylene sulfide is produced through the above-mentioned polymerization reaction step and recovery step, it can be subjected to a post-treatment step of acid treatment, hot water treatment, or washing with an organic solvent. From the viewpoint of removing impurities, the post-treatment step is preferably any one of acid treatment, hot water treatment, and washing with an organic solvent, and more preferably two or more types of treatments are used in combination.

[0095] The acid treatment is carried out as follows. The acid used in the acid treatment is not particularly limited as long as it does not have the effect of decomposing the polyarylene sulfide (A), and examples thereof include acetic acid, hydrochloric acid, sulfuric acid, phosphoric acid, silicic acid, carbonic acid, and propylic acid. Among these, acetic acid and hydrochloric acid are more preferably used. On the other hand, acids that decompose or deteriorate the polyarylene sulfide (A), such as nitric acid, are not preferred. The acid treatment method includes, for example, immersing the polyarylene sulfide (A) in an acid or an aqueous solution of an acid, and stirring or heating can be performed as necessary. When an acid solution is used, the solution may be either a solution using an organic solvent or an aqueous solution. However, an aqueous solution is preferred from the viewpoints of the tendency for the miscibility of the acid and the solubility of salts and basic components contained in the polyarylene sulfide to be relatively high. The water used is preferably distilled water or deionized water so as not to impair the desired chemical modification effect of the polyarylene sulfide. For example, when acetic acid is used, a sufficient effect can be obtained by immersing the polyarylene sulfide (A) powder in an aqueous acetic acid solution of pH 4 heated to 80°C to 200°C and stirring for 30 minutes. The pH after treatment may be 4 or higher, for example, about pH 4 to 8. In order to remove acid or salt remaining in the acid-treated polyarylene sulfide (A), it is preferable to further wash the polyarylene sulfide (A) several times with water or warm water. The water used for washing is preferably distilled water or deionized water so as not to impair the effect of the desirable chemical modification of the polyarylene sulfide (A). When performing acid treatment, when a polyarylene sulfide copolymer is obtained using the polyarylene sulfide (A), a polyarylene sulfide copolymer with a higher molecular weight tends to be obtained, which is preferable.

[0096] The hot water treatment is carried out as follows. When treating polyarylene sulfide (A) with hot water, the temperature of the hot water is preferably 100°C or higher, more preferably 120°C or higher, even more preferably 150°C or higher, and particularly preferably 170°C or higher. Temperatures below 100°C are not preferred because the desired chemical modification effect of polyarylene sulfide is small. In order to achieve the desired chemical modification effect of polyarylene sulfide (A) by hot water treatment, it is preferable to use distilled water or deionized water. There are no particular restrictions on the hot water treatment procedure. The hot water treatment can be carried out by adding a predetermined amount of polyarylene sulfide (A) to a predetermined amount of water, heating and stirring in a pressure vessel, or by continuous hot water treatment. The ratio of polyarylene sulfide (A) to water is preferably higher, but a bath ratio (weight of washing solution relative to the weight of dry polyarylene sulfide (A)) of 200 g or less of polyarylene sulfide (A) per liter of water is usually selected. In addition, in order to avoid undesirable decomposition of the reactive functional groups at the terminals, it is desirable to carry out the treatment in an inert atmosphere. Furthermore, in order to remove remaining components, it is preferable to wash the polyarylene sulfide (A) after this hot water treatment operation with warm water several times.

[0097] Washing with an organic solvent is as follows. There are no particular limitations on the organic solvent used to wash the polyarylene sulfide (A), as long as it does not decompose the polyarylene sulfide. Examples of organic solvents that can be used to wash the polyarylene sulfide (A) include nitrogen-containing polar solvents such as N-methyl-2-pyrrolidone, dimethylformamide, and dimethylacetamide; sulfoxide / sulfone solvents such as dimethyl sulfoxide, dimethyl sulfone, and sulfolane; ketone solvents such as acetone, methyl ethyl ketone, diethyl ketone, and acetophenone; ether solvents such as dimethyl ether, dipropyl ether, dioxane, and tetrahydrofuran; halogenated solvents such as chloroform, methylene chloride, trichloroethylene, ethylene dichloride, and perchloroethylene; alcohol solvents such as methanol, ethanol, propanol, butanol, pentanol, ethylene glycol, and propylene glycol; and aromatic hydrocarbon solvents such as benzene, toluene, and xylene. Among these organic solvents, N-methyl-2-pyrrolidone, acetone, dimethylformamide, and chloroform are preferred. Furthermore, from the viewpoint of removing impurities having an arylene sulfide structure, nitrogen-containing polar solvents such as N-methyl-2-pyrrolidone, dimethylformamide, and chloroform are particularly preferred, as they tend to provide relatively high solubility. These organic solvents may be used alone or in combination, or may be mixed with water. Washing with an organic solvent can be performed, for example, by immersing the polyarylene sulfide (A) in the organic solvent, with appropriate stirring or heating, if necessary. The washing temperature when washing the polyarylene sulfide (A) with an organic solvent is not particularly limited, and any temperature between room temperature and approximately 300°C can be selected. While higher washing temperatures tend to improve the washing efficiency, a washing temperature between room temperature and 150°C is usually sufficient. Washing can also be performed under pressure in a pressure vessel at a temperature above the boiling point of the organic solvent. The washing time is also not particularly limited. Although depending on the washing conditions, in the case of batch washing, washing for 5 minutes or more usually achieves sufficient results. Continuous washing is also possible.The organic solvent is preferred because it reduces the amount of gas generated when the polyarylene sulfide (A) is heated, and also because it tends to facilitate the production of a high molecular weight product when the polyarylene sulfide (A) is used to produce a polyarylene sulfide copolymer, which will be described later.

[0098] [Thermal oxidation crosslinking treatment] The polyarylene sulfide (A) can be used after being polymerized by a thermal oxidation crosslinking treatment, such as heating in an oxygen atmosphere or heating with a crosslinking agent such as peroxide added, to increase the molecular weight, provided that the number average molecular weight of the polyarylene sulfide (A) is 10,000 or less.

[0099] [Compound (B)] The compound (B) is at least one selected from the above formulae (a') to (u').

[0100] X is any one selected from two carboxyl groups bonded to two adjacent carbon atoms, or an acid anhydride group derived from the two carboxyl groups, and an amino group. From the viewpoint of reactivity when the above-mentioned polyarylene sulfide (A) and compound (B) are heated, the combination of the functional group of polyarylene sulfide (A) and the functional group of compound (B) is preferably an amino group and an acid anhydride group. Therefore, depending on the functional group of polyarylene sulfide (A), the functional group contained in compound (B) is preferably an amino group or an acid anhydride group. Furthermore, from the viewpoint of ease of polymerization reaction when producing polyarylene sulfide (A) by the above-mentioned production method, the functional group of polyarylene sulfide (A) is preferably an amino group, and accordingly, the functional group of compound (B) is preferably an acid anhydride group. R, R 1 , and R 2 is a substituent selected from hydrogen, an alkyl group having 1 to 12 carbon atoms, an arylene group having 6 to 24 carbon atoms, and a halogen group; R, R 1 , and R 2may be the same or different. Hydrogen, methyl, ethyl, or propyl is preferred due to their availability. The aromatic ring of each compound may be di- or tri-substituted, and the multiple substituents X substituted on one aromatic ring may be the same or different.

[0101] Specific examples of the compound (B) include pyromellitic acid, 3,3',4,4'-thiodiphthalic acid, 3,3',4,4'-sulfonyldiphthalic acid, 3,3',4,4'-benzophenonetetracarboxylic acid, 3,3',4,4'-sulfinyldiphthalic acid, 3,3',4,4'-biphenyltetracarboxylic acid, 3,3',4,4'-tetracarboxyldiphenylmethane, 9,9-bis(3,4-dicarboxyphenyl)fluorene, naphthalene-1,4,5,8-tetracarboxylic acid, bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic acid, 3,4,9,10-perylenetetracarboxylic acid, and pyromellitic anhydride. , 3,3',4,4'-thiodiphthalic anhydride, 3,3',4,4'-sulfonyldiphthalic anhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 3,3',4,4'-sulfinyldiphthalic anhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-tetracarboxylicdiphenylmethane dianhydride, 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride, naphthalene-1,4,5,8-tetracarboxylic dianhydride, glycerin bis(anhydrotrimellitate) monoacetate, ethylene glycol bis(anhydrotrimellitate), bicyclo[2.2.2] Oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 4,4'-thiodibenzoic acid, 4,4'-dicarboxylbenzophenone, 4,4'-sulfinyldibenzoic acid, 4,4'-dicarboxylbiphenyl, p-phenylenediamine, 4,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfone, 4,4'-diaminobenzophenone, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 2,7-diaminofluorene, o-toluidine, and 1,5-diaminonaphthalene are examples of compounds that are suitable for use as amines. ,3',4,4'-thiodiphthalic anhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 3,3',4,4'-sulfinyldiphthalic anhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride, 4,4'-thiodibenzoic acid, 4,4'-dicarboxylbenzophenone, 4,4'-sulfinyldibenzoic acid, 4,4'-dicarboxylbiphenylpyromellitic acid, pyromellitic anhydride, 4,4'-diaminodiphenyl sulfone, 4,4'-diaminobenzophenone, and 2,7-diaminofluorene are preferably used.

[0102] [Heating conditions for polyarylene sulfide (A) and compound (B)] The polyarylene sulfide copolymer of the present invention can be produced by heating polyarylene sulfide (A) having a number average molecular weight Mn of 1,000 or more and 10,000 or less and compound (B) under conditions in which the ratio of the total amount of amino groups to half of the total amount of carboxyl groups and acid anhydride groups contained in the polyarylene sulfide (A) and compound (B) is 0.75 or more and 0.97 or less, or 1.03 or more and 1.25 or less.

[0103] As mentioned above, it is preferable that the polyarylene sulfide copolymer has a large amount of either the amount of amino groups or the total amount of two carboxyl groups and acid anhydride groups bonded to two adjacent carbon atoms, respectively. For this reason, it is preferable that the ratio of half of the amount of carboxyl groups and the total amount of acid anhydride groups contained in the polyarylene sulfide (A) and the compound (B) to the total amount of amino groups is within the above range.

[0104] When a large amount of amino groups is desired, the lower limit of the ratio of the total amount of amino groups to half of the total amount of carboxyl groups and acid anhydride groups in the polyarylene sulfide (A) and the compound (B) is 0.75 or more. By setting the ratio within this range, the resulting polyarylene sulfide copolymer can have a sufficient amount of imide groups, thereby sufficiently suppressing a decrease in rigidity under high-temperature conditions. When a large amount of amino groups is desired, the upper limit of the ratio of the total amount of amino groups to half of the total amount of carboxyl groups and acid anhydride groups in the polyarylene sulfide (A) and the compound (B) is 0.97 or less, preferably 0.95 or less, more preferably 0.93 or less, even more preferably 0.90 or less, and even more preferably 0.85 or less. Setting the upper limit within the above range tends to result in the resulting polyarylene sulfide copolymer having excellent crystallinity, a high crystallization temperature, and excellent mechanical properties and chemical resistance.

[0105] When it is desired to increase the amount of acid anhydride groups and the two carboxyl groups bonded to each of the two adjacent carbon atoms, the upper limit of the ratio of the total amount of amino groups to half of the amount of carboxyl groups and the total amount of acid anhydride groups in the polyarylene sulfide (A) and the compound (B) is 1.25 or less. By setting the ratio within this range, the resulting polyarylene sulfide copolymer can have a sufficient amount of imide groups, thereby sufficiently suppressing a decrease in rigidity under high-temperature conditions. When it is desired to increase the amount of acid anhydride groups and the two carboxyl groups bonded to each of the two adjacent carbon atoms, the lower limit of the ratio of the total amount of amino groups to half of the amount of carboxyl groups and the total amount of acid anhydride groups in the polyarylene sulfide (A) and the compound (B) is 1.03 or more, preferably 1.06 or more, more preferably 1.10 or more, and even more preferably 1.15 or more. By setting the lower limit within the above range, the resulting polyarylene sulfide copolymer tends to have excellent crystallinity and a high crystallization temperature, and tends to exhibit excellent mechanical properties and chemical resistance.

[0106] The polyarylene sulfide (A) and the compound (B) may be heated by mixing the entire amount from the beginning, or by mixing and heating at least a portion of the polyarylene sulfide (A) and at least a portion of the compound (B) and then mixing and heating the remaining polyarylene sulfide (A) and / or compound (B). In the latter case, at least a portion of the polyarylene sulfide (A) and at least a portion of the compound (B) may be mixed and heated, and then the remaining polyarylene sulfide (A) and / or compound (B) may be mixed and heated, or at least a portion of the polyarylene sulfide (A) and at least a portion of the compound (B) may be mixed and heated, and then the product may be removed, and the remaining polyarylene sulfide (A) and / or compound (B) may be mixed and heated.

[0107] From the viewpoint of efficiently obtaining a polyarylene sulfide copolymer, it is preferable to mix and heat the entire amount of polyarylene sulfide (A) and compound (B) from the beginning. On the other hand, from the viewpoint of easily controlling and adjusting the thermal properties of the polyarylene sulfide copolymer, such as the glass transition temperature, crystallization temperature, and melting point, as well as the molecular weight, the terminal type and amount depending on the application, it is preferable to mix and heat at least a part of polyarylene sulfide (A) and at least a part of compound (B), and then mix and heat the remaining polyarylene sulfide (A) and / or compound (B).

[0108] The lower limit of the heating temperature can be, for example, 200°C or higher, preferably 230°C or higher, and more preferably 250°C or higher. By setting the lower limit of the heating temperature within this range, the reaction between the polyarylene sulfide (A) and the compound (B) can be easily promoted, and by setting the temperature at or above the temperature at which the polyarylene sulfide (A) melts, the reaction tends to be completed in a shorter time. The temperature at which the polyarylene sulfide (A) melts cannot be uniquely determined because it varies depending on the composition and molecular weight of the polyarylene sulfide (A) and the heating environment, but it can be determined, for example, by analyzing the polyarylene sulfide (A) with a differential scanning calorimeter. The upper limit of the heating temperature can be, for example, 400°C or lower, preferably 380°C or lower, and more preferably 360°C or lower. By setting the upper limit of the heating temperature within this range, undesirable side reactions, such as crosslinking reactions and decomposition reactions between polyarylene sulfides (A), can be suppressed, and deterioration in the properties of the resulting polyarylene sulfide copolymer tends to be suppressed.

[0109] The heating time cannot be specified uniquely because it varies depending on the composition and molecular weight of the polyarylene sulfide (A) and the heating environment, but it is preferable to set it so as to minimize the occurrence of the undesirable side reactions described above. The lower limit of the heating time can be, for example, 0.1 minutes or more, preferably 1 minute or more, more preferably 2 minutes or more, and even more preferably 3 minutes or more. By setting the lower limit of the heating time within this range, the reaction between the polyarylene sulfide (A) and the compound (B) can be more fully promoted. The upper limit of the heating time can be, for example, 100 hours or less, preferably 20 hours or less, more preferably 10 hours or less, and even more preferably 1 hour or less. Setting the upper limit of the heating time within this range tends to be economical and to avoid the undesirable side reactions described above.

[0110] In the method for producing a polyarylene sulfide copolymer of the present invention, an imide group is formed by reaction between an amino group possessed by the polyarylene sulfide (A) and the compound (B) and two carboxyl groups or acid anhydride groups bonded to two adjacent carbon atoms. The combination that forms the imide group may be either an amino group and two carboxyl groups bonded to two adjacent carbon atoms, or an amino group and an acid anhydride group. However, from the viewpoint of reactivity when the polyarylene sulfide (A) and the compound (B) are heated, a preferred combination of functional groups is an amino group and an acid anhydride group. Furthermore, from the viewpoint of ease of polymerization reaction when producing the polyarylene sulfide (A) by the above-mentioned production method, the functional group possessed by the polyarylene sulfide (A) is preferably an amino group, and accordingly, the functional group possessed by the compound (B) is preferably an acid anhydride group.

[0111] Heating can be carried out in the absence or presence of a solvent. When heating is carried out in the presence of a solvent, the solvent is not particularly limited as long as it does not substantially cause undesirable side reactions such as decomposition or crosslinking of the produced polyarylene sulfide copolymer. One type of solvent or a mixture of two or more types can be used. On the other hand, from the viewpoint of efficiently obtaining the polyarylene sulfide copolymer, it is preferable to carry out the heating under substantially solvent-free conditions. Furthermore, from the viewpoint of preventing contamination of molded products by generated gases when molding the obtained polyarylene sulfide copolymer, it is also preferable to carry out the heating under substantially solvent-free conditions. Here, substantially solvent-free conditions refer to a system in which the polyarylene sulfide (A) and the compound (B) are heated, with the solvent content being 10% by weight or less, preferably 3% by weight or less.

[0112] Heating in the method for producing the polyarylene sulfide copolymer of the present invention can be carried out not only by a method using a conventional polymerization reaction apparatus, but also in a mold for producing a molded product, or by using an extruder or a melt kneader, and can be carried out without any particular limitation as long as it is an apparatus equipped with a heating mechanism, and known methods such as a batch method and a continuous method can be employed.

[0113] The atmosphere during heating is preferably a non-oxidizing atmosphere, and it is also preferable to carry out the heating under reduced pressure conditions. Furthermore, when carrying out the heating under reduced pressure conditions, it is preferable to first change the atmosphere in the reaction system to a non-oxidizing atmosphere and then to a reduced pressure condition. This tends to suppress undesirable side reactions such as crosslinking reactions and decomposition reactions between polyarylene sulfides (A) or between the polyarylene sulfide copolymers produced. A non-oxidizing atmosphere refers to an atmosphere in which the oxygen concentration in the gas phase is 5% by volume or less, preferably 2% by volume or less, and more preferably an atmosphere that is substantially free of oxygen, i.e., an inert gas atmosphere such as nitrogen, helium, or argon. Among these, a nitrogen atmosphere is particularly preferred from the standpoints of economy and ease of handling. Furthermore, reduced pressure conditions refer to a pressure lower than atmospheric pressure within the reaction system, with the upper limit of the pressure being preferably 50 kPa or less, more preferably 20 kPa or less, and even more preferably 10 kPa or less. Setting the upper limit of the pressure within this range tends to suppress undesirable side reactions such as crosslinking reactions. An example of a lower limit of the pressure is 0.1 kPa or more. By setting the lower limit of the pressure to 0.1 kPa or more, it is possible to avoid a load on the reaction apparatus caused by reducing the pressure more than necessary.

[0114] [Polyarylene sulfide copolymer composition] The polyarylene sulfide copolymer of the present invention can also be used as a polyarylene sulfide copolymer composition containing the polyarylene sulfide copolymer of the present invention. As long as the polyarylene sulfide copolymer composition contains the polyarylene sulfide copolymer of the present invention, other optional components such as a crystal nucleating agent, various fillers, and other additives can also be blended therein.

[0115] The present invention also makes it possible to obtain a polyarylene sulfide copolymer composition containing a polyarylene sulfide copolymer (C) having, as a structural unit, an arylene sulfide unit having a number average molecular weight Mn of 1,000 or more and 10,000 or less, in which the arylene sulfide unit and a copolymerization component are linked via an imide group, and a crystal nucleating agent.

[0116] The lower limit of the glass transition point of the polyarylene sulfide copolymer composition is 95°C or higher, preferably 100°C or higher, and more preferably 110°C or higher. If the glass transition point is below 95°C, high rigidity cannot be obtained under high-temperature conditions. The upper limit of the glass transition point is 190°C or lower, preferably 180°C or lower, and more preferably 160°C or lower. If the glass transition point exceeds 190°C, the chemical resistance of the molded article will be insufficient. The glass transition point is defined as the inflection point of the baseline shift detected when the temperature is increased from 0°C to 340°C at a rate of 20°C / min using a differential scanning calorimeter.

[0117] The crystallization temperature of the polyarylene sulfide copolymer composition is 165°C or higher, preferably 170°C or higher, more preferably 180°C or higher, even more preferably 190°C or higher, and even more preferably 200°C or higher. A crystallization temperature below 165°C can result in reduced productivity due to insufficient crystallization when molding the copolymer composition or when further blending the copolymer composition with a filler and / or other additives to produce a resin composition, as described below, or insufficient crystallization of the resulting resin composition, resulting in reduced mechanical properties and chemical resistance. While there is no particular upper limit for the crystallization temperature, a range of 235°C or lower is typically exemplified. The crystallization temperature is defined as the peak crystallization temperature detected when a differential scanning calorimeter is used to heat a sample from 0°C to 340°C at a rate of 20°C / min, then held at 340°C for 1 minute, and then cooled to 100°C at a rate of 20°C / min.

[0118] The polyarylene sulfide copolymer composition preferably has a melting point of 300°C or lower. A melting point of 300°C or lower facilitates melt molding. The melting point is the melting peak temperature detected when the composition is heated using a differential scanning calorimeter from 0°C to 340°C at a rate of 20°C / min, held at 340°C for 1 minute, cooled to 100°C at a rate of 20°C / min, held at 100°C for 1 minute, and then heated again to 340°C at a rate of 20°C / min. The melting point can be adjusted by selecting the molecular weight of the arylene sulfide unit in the polyarylene sulfide copolymer composition.

[0119] [Polyarylene sulfide copolymer (C)] The polyarylene sulfide copolymer (C) contained in the polyarylene sulfide copolymer composition has the same characteristics as the polyarylene sulfide copolymer in terms of the repeating unit of the arylene sulfide unit, the number-average molecular weight of the arylene sulfide unit, the structure contained as a copolymerization component, the linking group between the arylene sulfide unit and the copolymerization component, the glass transition temperature of the polyarylene sulfide copolymer (C), the melting point of the polyarylene sulfide copolymer (C), and the molecular weight of the polyarylene sulfide copolymer (C). The crystallization temperature of the polyarylene sulfide copolymer (C) is not particularly limited, but is preferably 150°C or higher, more preferably 160°C or higher, and even more preferably 165°C or higher. When the crystallization temperature of the polyarylene sulfide copolymer (C) is within the above range, the crystallization temperature of the resulting polyarylene sulfide copolymer composition tends to be high.

[0120] [Nucleating agent] The nucleating agent contains at least one selected from talc, kaolin, an organic phosphorus compound, and polyether ether ketone. Among these, talc and polyether ether ketone are preferred, and polyether ether ketone is more preferred, in terms of the effect of increasing the crystallization temperature. Talc and polyether ether ketone are thought to have excellent dispersibility and compatibility in the polyarylene sulfide copolymer (C), thereby achieving a high crystallization temperature improvement effect. The inclusion of a nucleating agent tends to further increase the crystallization temperature of the polyarylene sulfide copolymer composition, and a sufficient crystallization rate can be obtained when molding the polyarylene sulfide copolymer composition or when further blending a filler and / or other additives to produce a resin composition. This improves productivity during the production of molded articles, and the resulting molded articles tend to exhibit excellent mechanical properties and chemical resistance due to crystallization. The lower limit of the amount of the nucleating agent can be 0.01 parts by weight or more, preferably 0.02 parts by weight or more, more preferably 0.05 parts by weight or more, even more preferably 0.1 parts by weight or more, even more preferably 0.2 parts by weight or more, and even more preferably 0.5 parts by weight or more, relative to 100 parts by weight of the polyarylene sulfide copolymer (C). By setting the lower limit of the amount of the nucleating agent within this range, a higher crystallization temperature improvement effect tends to be obtained. The upper limit of the amount of the nucleating agent can be 5 parts by weight or less, preferably 3 parts by weight or less, more preferably 2 parts by weight or less, and even more preferably 1 part by weight or less. By setting the upper limit of the amount of the nucleating agent within this range, the mechanical properties of the polyarylene sulfide copolymer composition tend to be sufficiently maintained.

[0121] The polyarylene sulfide copolymer of the present invention can also be used as a resin composition blended with various fillers and other additives in addition to a crystal nucleating agent. The blending method for producing the resin composition is not particularly limited, but a representative example includes a method in which the copolymer is fed into a known melt kneader such as a single-screw or twin-screw extruder, a Banbury mixer, a kneader, or a mixing roll, and kneaded at a processing temperature of 5 to 100°C above the melting peak temperature of the polyarylene sulfide copolymer.

[0122] Examples of fillers include inorganic fillers and organic fillers. The type of filler is not limited, but considering the reinforcing effect of the filler in the resin composition, fibrous inorganic fillers such as glass fiber and carbon fiber are preferred. Carbon fiber not only improves mechanical properties but also reduces the weight of molded products. Furthermore, when the filler is carbon fiber, the effect of improving the mechanical properties and chemical resistance of the resin composition is more pronounced, making it more preferred.

[0123] The polyarylene sulfide copolymer composition has excellent heat resistance, chemical resistance, flame retardancy, electrical properties, and mechanical properties, and can be molded into extrusion molded products such as sheets, films, fibers, and pipes by extrusion molding as well as injection molding, injection compression molding, and blow molding.

[0124] In addition, examples of uses of the polyarylene sulfide copolymer composition include electric and electronic parts, audio equipment parts, household and office electrical appliance parts, machine-related parts, optical equipment, precision machinery-related parts, plumbing parts, automobile and vehicle-related parts, aerospace-related parts, and various other uses. [Example]

[0125] The method of the present invention will be explained in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples alone.

[0126] [Analysis of functional group content] The amount of amino groups in the polyarylene sulfide, polyarylene sulfide copolymer, polyarylene sulfide copolymer composition, and polyarylene sulfide copolymer (C), as well as the total amount of two carboxyl groups and acid anhydride groups bonded to two adjacent carbon atoms, were measured by FT-IR (IR-810 infrared spectrophotometer, manufactured by JASCO Corporation) of an amorphous film prepared by quenching from a molten state obtained by heating at 320°C, and the amount of the 1901 cm derivative of the benzene ring of the arylene sulfide unit was measured. -1 The absorption intensity at 3382 cm originating from the amino group -1or the absorption intensity at 1860 cm -1 The absorption intensity was estimated by comparing the

[0127] [Molecular weight measurement] The number average molecular weight Mn and weight average molecular weight Mw were calculated in terms of polystyrene by gel permeation chromatography (GPC), a type of size exclusion chromatography (SEC). The GPC measurement conditions are shown below. Equipment: Senshu Science SSC-7110 Column name: Shodex UT806M x 2 Eluent: 1-chloronaphthalene Detector: Differential refractive index detector Column temperature: 210℃ Pre-thermostat temperature: 250℃ Pump thermostatic bath temperature: 50℃ Detector temperature: 210℃ Flow rate: 1.0mL / min Sample injection volume: 300 μL.

[0128] [Measurement of weight loss rate upon heating] The weight loss rate of the polyarylene sulfide upon heating was measured using a thermogravimetric analyzer under the following conditions. Apparatus: PerkinElmer TGA7 Measurement atmosphere: Nitrogen flow Sample weight: approx. 5 mg Measurement conditions (a) Program temperature 30℃, hold for 1 minute (b) The program temperature was increased from 30°C to 340°C at a rate of 10°C / min. The weight loss rate was calculated from the weight measured under the above conditions at 320°C and the weight measured at 30°C using the following formula. Weight loss rate (%) = ((weight (mg) at 30°C - weight (mg) at 320°C) / weight (mg) at 30°C) × 100.

[0129] [Measurement of glass transition temperature, melting point and crystallization temperature] The glass transition temperature (Tg), melting point (Tm), and crystallization temperature (Tmc) were measured by differential scanning calorimetry (DSC) using approximately 10 mg of amorphous film prepared by quenching from the molten state. The glass transition temperature was determined as the inflection point of the baseline shift detected when the temperature was increased from 0 to 340 °C at a rate of 20 °C / min. The crystallization temperature was determined as the crystallization peak temperature detected when the temperature was increased from 0 to 340 °C at a rate of 20 °C / min, held at 340 °C for 1 minute, and cooled to 100 °C at a rate of 20 °C / min. The melting point was determined as the melting peak temperature detected when the temperature was increased from 0 to 340 °C at a rate of 20 °C / min, held at 340 °C for 1 minute, cooled to 100 °C at a rate of 20 °C / min, held at 100 °C for 1 minute, and then heated again to 340 °C at a rate of 20 °C / min. Equipment: TA Instruments TA-Q200 Carrier gas: Nitrogen Sample purge flow rate: 50 mL / min.

[0130] [Reference example 1] An autoclave equipped with a stirrer and a bottom stop valve was charged with 7.14 kg (61.6 mol) of 48.4% sodium hydrosulfide, 2.87 kg (69.3 mol) of 97% sodium hydroxide, 14.57 kg (147 mol) of N-methyl-2-pyrrolidone (NMP), and 4.19 kg of ion-exchanged water, and gradually heated to 225°C over approximately 3 hours at atmospheric pressure while passing nitrogen through. Heating was stopped and cooling was initiated when 7.88 kg of water and 0.039 kg of NMP had distilled out. At this point, the amount of hydrogen sulfide released was 1.4 mol, so the amount of inorganic sulfidizing agent in the system after this step was 60.2 mol.

[0131] The mixture was then cooled to 200°C, and 9.45 kg (64.3 mol) of p-dichlorobenzene (p-DCB), 1.02 kg (8.23 mol) of 4-aminothiophenol (4-ATP), and 2.78 kg (28.0 mol) of NMP were added. The reaction vessel was then sealed under nitrogen gas, and the temperature was raised to 260°C at a rate of 0.6°C / min with stirring, and the mixture was reacted at 260°C for 120 minutes.

[0132] Immediately after the reaction was completed, the bottom plug valve of the autoclave was opened, and the contents were flushed into an apparatus equipped with a stirrer, which was then dried and solidified for 1.5 hours at 230°C in the apparatus equipped with a stirrer, and a solid containing PPS and salts was recovered.

[0133] The recovered material and ion-exchanged water were placed in an autoclave equipped with a stirrer, washed at 75°C for 15 minutes, and then filtered three times to obtain a cake. The resulting cake and 30 liters of ion-exchanged water were placed in an autoclave equipped with a stirrer, the inside of the autoclave was replaced with nitrogen, and the temperature was raised to 195°C. The autoclave was then cooled, and the contents were filtered to obtain a cake. The resulting cake was dried at 120°C under a nitrogen stream.

[0134] 3 kg of the resulting PPS and 30 kg of N-methyl-2-pyrrolidone (NMP) were placed in a container equipped with a stirrer and stirred for 30 minutes, after which the mixture was filtered to obtain a cake. The resulting cake was washed with 30 L of ion-exchanged water for 15 minutes and filtered three times, and then dried at 120°C for 4 hours under a nitrogen stream to obtain dried PPS. The amino group content was 730 μmol / g, the number-average molecular weight was 1,800, and the weight loss upon heating was 1 wt%.

[0135] [Example 1] The PPS obtained in Reference Example 1 and pyromellitic anhydride were placed in a reactor equipped with a stirring blade and capable of being evacuated and purged with nitrogen so that the ratio of the amount of acid anhydride groups in pyromellitic anhydride to the amount of amino groups in PPS was 0.81, and the reactor was then repeatedly evacuated and purged with nitrogen three times. With the reactor filled with a nitrogen atmosphere, the temperature was adjusted to 300°C and the mixture was heated with stirring for 3 minutes, and then cooled to room temperature to obtain a polyarylene sulfide copolymer.

[0136] From the FT-IR spectrum, it was confirmed that the obtained polyarylene sulfide copolymer contains phenylene sulfide units as structural units and that imide groups have been introduced. In addition, from the FT-IR spectrum, it was confirmed that the 1901 cm 2 derived from the benzene ring of the arylene sulfide unit -1The absorption intensity at 3382 cm originating from the amino group -1 The specific intensity of the absorption at 1860 cm due to the acid anhydride group was 0.64. -1 No absorption was observed at 100°C. DSC measurements revealed that the glass transition temperature was 97°C, the crystallization temperature was 196°C, and the melting point was 266°C. The results are summarized in Table 1.

[0137] [Example 2] The PPS obtained in Reference Example 1 and pyromellitic anhydride were placed in a reactor equipped with a stirring blade and capable of being evacuated and purged with nitrogen so that the ratio of the amount of acid anhydride groups in the pyromellitic anhydride to the amount of amino groups in the PPS was 1.20. The reactor was then repeatedly evacuated and purged with nitrogen three times. The reactor was filled with a nitrogen atmosphere and heated to 300°C with stirring for 3 minutes, after which it was cooled to room temperature to obtain a polyarylene sulfide copolymer. The PPS obtained in Reference Example 1 was then added to the resulting polyarylene sulfide copolymer so that the ratio of the amount of acid anhydride groups in the pyromellitic anhydride to the amount of amino groups in the PPS was 0.95, based on the total amount used in the reaction in Example 2. The resulting mixture was then placed in a reactor equipped with a stirring blade and capable of being evacuated and purged with nitrogen three times. The reactor was filled with a nitrogen atmosphere and heated to 300°C with stirring for 3 minutes, after which it was cooled to room temperature to obtain a polyarylene sulfide copolymer.

[0138] From the FT-IR spectrum, it was confirmed that the obtained polyarylene sulfide copolymer contains phenylene sulfide units as structural units and that imide groups have been introduced. In addition, from the FT-IR spectrum, it was confirmed that the 1901 cm 2 derived from the benzene ring of the arylene sulfide unit -1 The absorption intensity at 3382 cm originating from the amino group -1 The specific intensity of the absorption at 1860 cm due to the acid anhydride group was 0.13. -1 No absorption was observed at 100°C. DSC measurements revealed that the glass transition temperature was 112°C, the crystallization temperature was 172°C, and the melting point was 256°C. The results are summarized in Table 1.

[0139] [Comparative Example 1] An operation was carried out under the same conditions as in Example 1, except that the PPS obtained in Reference Example 1 and pyromellitic anhydride were charged into a reaction vessel equipped with a stirring blade that could be reduced in pressure and substituted with nitrogen, so that the ratio of the amount of acid anhydride groups in pyromellitic anhydride to the amount of amino groups in PPS was 0.98, thereby obtaining a polyarylene sulfide copolymer.

[0140] From the FT-IR spectrum, it was confirmed that the obtained polyarylene sulfide copolymer contains phenylene sulfide units as structural units and that imide groups have been introduced. In addition, from the FT-IR spectrum, it was confirmed that the 1901 cm 2 derived from the benzene ring of the arylene sulfide unit -1 The absorption intensity at 3382 cm originating from the amino group -1 The relative intensity of the absorption at 1860 cm due to the acid anhydride group was 0.10. -1 No absorption was observed at 100°C. DSC measurements revealed that the glass transition temperature was 112°C, the crystallization temperature was 163°C, and the melting point was 256°C. The results are summarized in Table 1.

[0141] [Example 3] An operation was carried out under the same conditions as in Example 1, except that the PPS obtained in Reference Example 1 and pyromellitic anhydride were charged into a reaction vessel equipped with a stirring blade that could be reduced in pressure and substituted with nitrogen, so that the ratio of the amount of acid anhydride groups in pyromellitic anhydride to the amount of amino groups in PPS was 1.20, thereby obtaining a polyarylene sulfide copolymer.

[0142] From the FT-IR spectrum, it was confirmed that the obtained polyarylene sulfide copolymer contains phenylene sulfide units as structural units and that imide groups have been introduced. In addition, from the FT-IR spectrum, it was confirmed that the 1901 cm 2 derived from the benzene ring of the arylene sulfide unit -1 The absorption intensity at 1860cm originating from the acid anhydride group -1 The relative intensity of the absorption at 3382 cm due to the amino group was 1.79. -1No absorption was observed at 100°C. DSC measurements revealed that the glass transition temperature was 113°C, the crystallization temperature was 206°C, and the melting point was 259°C. The results are summarized in Table 1.

[0143] [Example 4] An operation was carried out under the same conditions as in Example 1, except that the PPS obtained in Reference Example 1 and pyromellitic anhydride were charged into a reaction vessel equipped with a stirring blade that could be reduced in pressure and substituted with nitrogen, so that the ratio of the amount of acid anhydride groups in pyromellitic anhydride to the amount of amino groups in PPS was 1.03, thereby obtaining a polyarylene sulfide copolymer.

[0144] From the FT-IR spectrum, it was confirmed that the obtained polyarylene sulfide copolymer contains phenylene sulfide units as structural units and that imide groups have been introduced. In addition, from the FT-IR spectrum, it was confirmed that the 1901 cm 2 derived from the benzene ring of the arylene sulfide unit -1 The absorption intensity at 1860cm originating from the acid anhydride group -1 The relative intensity of the absorption at 3382 cm due to the amino group was 0.50. -1 No absorption was observed at 100°C. DSC measurements revealed that the glass transition temperature was 113°C, the crystallization temperature was 198°C, and the melting point was 256°C. The results are summarized in Table 1.

[0145] [Example 5] An operation was carried out under the same conditions as in Example 1, except that the PPS obtained in Reference Example 1 and pyromellitic anhydride were charged into a reaction vessel equipped with a stirring blade that could be reduced in pressure and substituted with nitrogen, so that the ratio of the amount of acid anhydride groups in pyromellitic anhydride to the amount of amino groups in PPS was 1.02, thereby obtaining a polyarylene sulfide copolymer.

[0146] From the FT-IR spectrum, it was confirmed that the obtained polyarylene sulfide copolymer contains phenylene sulfide units as structural units and that imide groups have been introduced. In addition, from the FT-IR spectrum, it was confirmed that the 1901 cm 2 derived from the benzene ring of the arylene sulfide unit -1 The absorption intensity at 1860cm originating from the acid anhydride group-1 The relative intensity of the absorption at 3382 cm due to the amino group was 0.38. -1 No absorption was observed at 100°C. DSC measurements revealed that the glass transition temperature was 114°C, the crystallization temperature was 197°C, and the melting point was 256°C. The results are summarized in Table 1.

[0147] [Example 6] The PPS obtained in Reference Example 1 and pyromellitic anhydride were placed in a reactor equipped with a stirring blade and capable of being evacuated and purged with nitrogen so that the ratio of the amount of acid anhydride groups in the pyromellitic anhydride to the amount of amino groups in the PPS was 1.20. The reactor was then repeatedly evacuated and purged with nitrogen three times. The reactor was filled with a nitrogen atmosphere and heated to 300°C with stirring for 3 minutes, after which it was cooled to room temperature to obtain a polyarylene sulfide copolymer. The PPS obtained in Reference Example 1 was then added to the resulting polyarylene sulfide copolymer so that the ratio of the amount of acid anhydride groups in the pyromellitic anhydride to the amount of amino groups in the PPS was 1.01, based on the total amount used in the reaction of Example 6. The resulting mixture was then placed in a reactor equipped with a stirring blade and capable of being evacuated and purged with nitrogen three times. The reactor was filled with a nitrogen atmosphere and heated to 300°C with stirring for 3 minutes, after which it was cooled to room temperature to obtain a polyarylene sulfide copolymer.

[0148] From the FT-IR spectrum, it was confirmed that the obtained polyarylene sulfide copolymer contains phenylene sulfide units as structural units and that imide groups have been introduced. In addition, from the FT-IR spectrum, it was confirmed that the 1901 cm 2 derived from the benzene ring of the arylene sulfide unit -1 The absorption intensity at 1860cm originating from the acid anhydride group -1 The relative intensity of the absorption at 3382 cm due to the amino group was 0.26. -1 No absorption was observed at 100°C. DSC measurements revealed that the glass transition temperature was 114°C, the crystallization temperature was 171°C, and the melting point was 254°C. The results are summarized in Table 1.

[0149] Comparative Example 2 An operation was carried out under the same conditions as in Example 1, except that the PPS obtained in Reference Example 1 and pyromellitic anhydride were charged into a reaction vessel equipped with a stirring blade that could be reduced in pressure and substituted with nitrogen, so that the ratio of the amount of acid anhydride groups in pyromellitic anhydride to the amount of amino groups in PPS was 1.002, thereby obtaining a polyarylene sulfide copolymer.

[0150] From the FT-IR spectrum, it was confirmed that the obtained polyarylene sulfide copolymer contains phenylene sulfide units as structural units and that imide groups have been introduced. In addition, from the FT-IR spectrum, it was confirmed that the 1901 cm 2 derived from the benzene ring of the arylene sulfide unit -1 The absorption intensity at 1860cm originating from the acid anhydride group -1 The relative intensity of the absorption at 3382 cm due to the amino group was 0.18. -1 No absorption was observed at 100°C. DSC measurements revealed that the glass transition temperature was 115°C, the crystallization temperature was 161°C, and the melting point was 252°C. The results are summarized in Table 1.

[0151] [Reference example 2] In Reference Example 2, an amino group-containing polyarylene sulfide was obtained by the method disclosed in WO 2019 / 151288.

[0152] An autoclave equipped with a stirrer was charged with 8.27 kg (70.00 mol) of 47.5% sodium hydrosulfide, 2.96 kg (70.97 mol) of 96% sodium hydroxide, 11.4 kg (115.50 mol) of N-methyl-2-pyrrolidone (NMP), 2.58 kg (31.50 mol) of sodium acetate, and 10.5 kg of ion-exchanged water. The mixture was gradually heated to 245°C over approximately 3 hours under atmospheric pressure while passing nitrogen through. After distilling off 14.8 kg of water and 280 g of NMP, the reactor was cooled to 160°C. The amount of water remaining in the system per mole of charged alkali metal sulfide was 1.06 mol, including the water consumed in the hydrolysis of NMP. The amount of hydrogen sulfide released was 0.02 mol per mole of charged alkali metal sulfide.

[0153] Next, 10.24 kg (69.63 mol) of p-dichlorobenzene and 9.01 kg (91.00 mol) of NMP were added, and the reaction vessel was sealed under nitrogen gas. The mixture was heated to 238°C at a rate of 0.6°C / min with stirring. After 95 minutes of reaction at 238°C, the mixture was heated to 270°C at a rate of 0.8°C / min. After 100 minutes of reaction at 270°C, the mixture was cooled to 250°C at a rate of 1.3°C / min while injecting 1.26 kg (70 mol) of water over 15 minutes. The mixture was then cooled to 200°C at a rate of 1.0°C / min and then rapidly cooled to near room temperature.

[0154] The contents were removed and diluted with 26.3 kg of NMP. The solvent and solids were filtered through a sieve (80 mesh). The resulting particles were washed with 31.9 kg of NMP and filtered. These were then washed several times with 56 kg of ion-exchanged water and filtered. After washing with 70 kg of ion-exchanged water and filtering, the resulting hydrated PPS particles were dried with hot air at 80°C and then dried under reduced pressure at 120°C to obtain PPS.

[0155] 80 g of the resulting PPS and 12 g of 4,4'-thiodianiline (TDA) were placed in a glass test tube equipped with a stirring blade and capable of vacuuming and nitrogen flushing. The test tube was then vacuumed and purged with nitrogen three times. The test tube was filled with a nitrogen atmosphere and heated to 340°C for 180 minutes with stirring to obtain PPS. The amino group content was 1,100 μmol / g, the number-average molecular weight was 2,300, and the weight loss upon heating was 7 wt%.

[0156] Comparative Example 3 The PPS obtained in Reference Example 2 and pyromellitic anhydride were placed in a reactor equipped with a stirring blade and capable of being evacuated and purged with nitrogen so that the ratio of the amount of acid anhydride groups in the pyromellitic anhydride to the amount of amino groups in the PPS was 1.02, and the reactor was then repeatedly evacuated and purged with nitrogen three times. With the reactor filled with a nitrogen atmosphere, the temperature was adjusted to 320°C and the mixture was heated with stirring for 20 minutes, and then cooled to room temperature to obtain a polyarylene sulfide copolymer.

[0157] From the FT-IR spectrum, it was confirmed that the obtained polyarylene sulfide copolymer contains phenylene sulfide units as structural units and that imide groups have been introduced. In addition, from the FT-IR spectrum, it was confirmed that the 1901 cm 2 derived from the benzene ring of the arylene sulfide unit -1 The absorption intensity at 1860cm originating from the acid anhydride group -1 The relative intensity of the absorption at 3382 cm due to the amino group was 0.53. -1 As a result of DSC measurement, the glass transition temperature was 122°C, no crystallization peak was observed, and the melting point was 250°C. The results are summarized in Table 1.

[0158] [Table 1]

[0159] In addition, PDA in the table refers to pyromellitic anhydride.

[0160] As shown in Examples 1 to 6, the present invention makes it possible to obtain a polyarylene sulfide copolymer having a crystallization temperature of 165° C. or higher and high crystallinity.

[0161] A comparison of the IR measurement results and the ratio of the amount of acid anhydride groups to the amount of amino groups in Example 1, Example 2, and Comparative Example 1 shows that higher crystallinity can be obtained by having a polyarylene sulfide copolymer with a large number of amino groups and therefore by reducing the ratio of the amount of acid anhydride groups to the amount of amino groups. Furthermore, the results of Example 1 and Example 2 show that the entire amounts of polyarylene sulfide and compound (B) can be mixed and heated from the beginning, or at least a portion of the polyarylene sulfide and at least a portion of compound (B) can be mixed and heated, and the remainder can be mixed and heated.

[0162] A comparison of the IR measurement results and the ratio of the amount of acid anhydride groups to the amount of amino groups in Examples 3 to 6 and Comparative Example 2 shows that higher crystallinity can be obtained by having a polyarylene sulfide copolymer with a large number of acid anhydride groups and therefore by increasing the ratio of the amount of acid anhydride groups to the amount of amino groups. Furthermore, the results of Examples 3 to 5 and Example 6 show that the polyarylene sulfide and compound (B) can be heated by mixing the entire amount from the beginning and heating, or by mixing at least a portion of the polyarylene sulfide and at least a portion of the compound (B) and heating them, and then mixing and heating the remainder.

[0163] Furthermore, as shown in Comparative Example 3, when a conventional method for producing polyarylene sulfide is used, even if the polyarylene sulfide copolymer has a large number of acid anhydride groups and therefore the ratio of the amount of acid anhydride groups to the amount of amino groups is increased, no crystallization temperature is observed, and it is understood that the crystallinity is not excellent. The polyarylene sulfide of Reference Example 2 contains components that are likely to become gas components when heated, and it is thought that these components or a part of them affected the crystallinity.

[0164] [Example 7] The polyarylene sulfide copolymer obtained in Example 2 and 0.1 part by weight of polyether ether ketone (PEEK 450PF, manufactured by Victrex) were charged into a reaction vessel equipped with a stirring blade and capable of reducing pressure and replacing with nitrogen, and the reaction vessel was repeatedly reduced in pressure and replaced with nitrogen three times. With the reaction vessel filled with a nitrogen atmosphere, the temperature was adjusted to 300°C and the mixture was heated with stirring for 3 minutes, and then cooled to room temperature to obtain a polyarylene sulfide copolymer composition.

[0165] As a result of DSC measurement, the glass transition temperature was 112° C., the crystallization temperature was 174° C., and the melting point was 256° C. The results are summarized in Table 2.

[0166] [Example 8] An operation was carried out under the same conditions as in Example 7, except that the polyarylene sulfide copolymer obtained in Example 2 and 0.5 parts by weight of polyether ether ketone (PEEK 450PF, manufactured by Victrex) were charged into a reaction vessel equipped with a stirring blade that could be reduced in pressure and substituted with nitrogen, to obtain a polyarylene sulfide copolymer composition.

[0167] As a result of DSC measurement, the glass transition temperature was 112° C., the crystallization temperature was 177° C., and the melting point was 255° C. The results are summarized in Table 2.

[0168] [Example 9] The same conditions as in Example 8 were used except that the temperature inside the reaction vessel was changed to 340°C, to obtain a polyarylene sulfide copolymer composition.

[0169] As a result of DSC measurement, the glass transition temperature was 112° C., the crystallization temperature was 174° C., and the melting point was 255° C. The results are summarized in Table 2.

[0170] [Example 10] An operation was carried out under the same conditions as in Example 8, except that talc ("Hitron" (average particle size 4.0 μm) manufactured by Takehara Chemical Industry Co., Ltd.) was used as the nucleating agent, to obtain a polyarylene sulfide copolymer composition.

[0171] As a result of DSC measurement, the glass transition temperature was 113° C., the crystallization temperature was 180° C., and the melting point was 255° C. The results are summarized in Table 2.

[0172] [Example 11] An operation was carried out under the same conditions as in Example 9, except that the polyarylene sulfide copolymer obtained in Comparative Example 2 was used as the polyarylene sulfide copolymer, to obtain a polyarylene sulfide copolymer composition.

[0173] As a result of DSC measurement, the glass transition temperature was 116° C., the crystallization temperature was 178° C., and the melting point was 253° C. The results are summarized in Table 2.

[0174] [Example 12] An operation was carried out under the same conditions as in Example 10, except that the polyarylene sulfide copolymer obtained in Comparative Example 2 was used as the polyarylene sulfide copolymer, to obtain a polyarylene sulfide copolymer composition.

[0175] As a result of DSC measurement, the glass transition temperature was 114° C., the crystallization temperature was 166° C., and the melting point was 252° C. The results are summarized in Table 2.

[0176] [Table 2]

[0177] In the table, PEEK refers to polyether ether ketone.

[0178] As shown in Examples 7 to 12, the present invention makes it possible to obtain a polyarylene sulfide copolymer composition having a crystallization temperature of 165° C. or higher and high crystallinity.

[0179] A comparison of Example 2 with Examples 7 to 10 shows that a polyarylene sulfide copolymer exhibiting high crystallinity can achieve higher crystallinity by further containing a crystal nucleating agent. A comparison of Examples 7 and 8 shows that a higher crystallinity can be achieved by increasing the amount of crystal nucleating agent added.

[0180] Comparison of Comparative Example 2 with Examples 11 and 12 shows that the nucleating agent is effective even for polyarylene sulfide copolymers with insufficient crystallinity, and that high crystallinity can be obtained by including the nucleating agent.

Claims

1. A polyarylene sulfide copolymer characterized by having a number average molecular weight Mn of 1,000 or more and 10,000 or less, having, as structural units, arylene sulfide units containing 80 moles or more of p-phenylene sulfide units represented by the following formula (XV), and having a structure in which the arylene sulfide units and a structure represented by the following formula (i) are linked via imide groups, and having a glass transition point of 95°C or more and 190°C or less as measured by differential scanning calorimetry, and having a crystallization temperature of 165°C or more. 【Chemistry 1】 【Chemistry 2】 (R 1 and R 2 are substituents selected from hydrogen, alkyl groups having 1 to 12 carbon atoms, arylene groups having 6 to 24 carbon atoms, and halogen groups, and R 1 and R 2 may be the same or different.)

2. 1901 cm derived from the benzene ring of the arylene sulfide unit －１ The absorption intensity at 3382 cm due to the amino group －１ The specific intensity of absorption at 1860 cm －１ 2. The polyarylene sulfide copolymer according to claim 1, wherein the specific intensity of absorption at 1000 nm is 0.20 or more and 2.2 or less.

3. 3. The polyarylene sulfide copolymer according to claim 1, which has a melting point of 300° C. or less.

4. 4. The method for producing a polyarylene sulfide copolymer according to claim 1, comprising heating an arylene sulfide (A) having a number average molecular weight Mn of 1,000 or more and 10,000 or less, the arylene sulfide (A) having amino groups and containing 80 moles or more of p-phenylene sulfide units represented by formula (XV), and a compound (B) represented by formula (i'): 【Transformation 3】 (X is either one selected from two carboxyl groups bonded to two adjacent carbon atoms, or an acid anhydride group derived from the two carboxyl groups; R 1 and R ２ are substituents selected from hydrogen, alkyl groups having 1 to 12 carbon atoms, arylene groups having 6 to 24 carbon atoms, and halogen groups; R 1 and R ２ may be the same or different. The aromatic ring of each compound may be di- or tri-substituted, and the multiple substituents X substituted on one aromatic ring may be the same or different.

5. The method for producing a polyarylene sulfide copolymer according to claim 4, wherein at least a part of the polyarylene sulfide (A) and at least a part of the compound (B) are mixed and heated, and then the remaining polyarylene sulfide (A) and / or the compound (B) are mixed and heated.

6. The method for producing a polyarylene sulfide copolymer according to claim 4 or 5, wherein the heating is carried out substantially in the absence of a solvent.

7. A polyarylene sulfide copolymer composition comprising: a polyarylene sulfide copolymer (C) having a number average molecular weight Mn of 1,000 or more and 10,000 or less, which has, as structural units, arylene sulfide units containing 80 moles or more of p-phenylene sulfide units represented by the following formula (XV), and which has a structure in which the arylene sulfide units and a structure represented by the following formula (i) are linked via an imide group; and a crystal nucleating agent; and the polyarylene sulfide copolymer composition has a glass transition point of 95°C or more and 190°C or less, as measured by differential scanning calorimetry, and a crystallization temperature of 165°C or more. 【Chemistry 4】 【Transformation 5】 (R 1 and R 2 are substituents selected from hydrogen, alkyl groups having 1 to 12 carbon atoms, arylene groups having 6 to 24 carbon atoms, and halogen groups, and R 1 and R 2 may be the same or different.)

8. The polyarylene sulfide copolymer composition according to claim 7, wherein at least a part of the polyarylene sulfide copolymer (C) is the polyarylene sulfide copolymer according to any one of claims 1 to 3.

9. A polyarylene sulfide copolymer composition comprising the polyarylene sulfide copolymer according to any one of claims 1 to 3.

10. A molded article obtained by molding the polyarylene sulfide copolymer composition according to any one of claims 7 to 9.

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