JP2024019036A - Polyarylene sulfide copolymer fine particles, method for producing the same, and polyarylene sulfide copolymer fine particle dispersion - Google Patents

Abstract

The present invention provides polyarylene sulfide copolymer fine particles having a high glass transition point and high molecular weight, a method for producing the same, and a polyarylene sulfide copolymer fine particle dispersion. [Solution] The product has a glass transition point measured by differential scanning calorimetry of 95°C or more and 190°C or less, a weight average molecular weight Mw of 30,000 or more, and a median diameter D50 of 10 μm or more and 150 μm or less. These are polyarylene sulfide copolymer fine particles. [Selection diagram] None

Description

The present invention relates to polyarylene sulfide copolymer fine particles, a method for producing the same, and a polyarylene sulfide copolymer fine particle dispersion.

Polyarylene sulfide, represented by polyphenylene sulfide (hereinafter sometimes abbreviated as PPS), has properties suitable for engineering plastics, such as excellent heat resistance, barrier properties, moldability, chemical resistance, electrical insulation properties, and heat and humidity resistance. It is used mainly for injection molding and extrusion molding, as well as various electrical and electronic parts, mechanical parts, automobile parts, films, and textiles. Due to its excellent properties, polyarylene sulfide has been used in a wide range of applications in recent years.

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 used under high-temperature conditions due to its excellent heat resistance. There are many things. It is also widely used in applications that take advantage of its excellent chemical resistance.

However, while the above-mentioned PPS, which is a typical example of polyarylene sulfide, can withstand use at high temperatures due to its high melting point, it rapidly deteriorates at temperatures above 80 to 90 degrees Celsius, which is above the glass transition point, compared to lower temperatures. There is a problem in that the rigidity decreases. Various studies have been conducted to improve the glass transition point of polyarylene sulfide. For example, Patent Documents 1 to 3 describe polyarylene sulfide obtained by reacting polyarylene sulfide having a reactive functional group with a rigid molecule. Copolymers are disclosed.

Polyarylene sulfide copolymers, which have excellent chemical resistance and higher heat resistance, are used in injection molding, injection compression molding, blow molding, and extrusion molding. It can be used as a heat-resistant additive in the fields of adhesive materials, paints, and polymer compounds, and as a raw material for three-dimensional modeling using the powder bed fusion bonding method, and is expected to be used in a wider range of applications. Furthermore, when producing a resin composition by blending such a polyarylene sulfide copolymer with fillers and/or other additives, a more uniform resin composition can be obtained by blending with fine particles. There are expectations that can be obtained efficiently.

Various methods for producing thermoplastic resin fine particles have been studied, and for example, Patent Documents 4 to 6 disclose that PPS or polyarylene sulfide fine particles obtained by dissolving PPS or polyarylene sulfide in a solvent and precipitating the same are disclosed in Patent Documents 4 to 6. Patent Document 8 discloses a polyarylene sulfide resin powder obtained by dry-pulverizing polyarylene sulfide, and Patent Document 8 discloses a polyarylene sulfide resin powder obtained by melt-kneading PPS with other thermoplastic polymers. A fine spherical PPS powder obtained by washing with a solvent in which PPS is dissolved is disclosed.

International Publication No. 2019/151288 International Publication No. 2022/045105 International Publication No. 2021/020334 JP2008-231250A Japanese Patent Application Publication No. 2007-154166 International Publication No. 2009/119466 International Publication No. 2019/203256 Japanese Patent Application Publication No. 10-273594

Although the polyarylene sulfide copolymers disclosed in Patent Documents 1 to 3 have a high glass transition point, the polyarylene sulfide copolymers are manufactured by heating in a molten state in the absence of a solvent. However, polyarylene sulfide copolymer fine particles were not obtained by such a manufacturing method. Further, although there is a description of manufacturing a polyarylene sulfide copolymer in the presence of a solvent, there is no description of fine particles or a specific manufacturing method. Patent Document 3 describes a method for producing a fiber-reinforced polyarylene sulfide copolymer composite base material, and describes a method using a powdered polyarylene sulfide copolymer. There was no description of a specific method for obtaining coalescence or a method for producing a composite base material using a powdered polyarylene sulfide copolymer.

The PPS or polyarylene sulfide fine particles disclosed in Patent Documents 4 to 6 are manufactured by dissolving PPS or polyarylene sulfide in a solvent and precipitating it. When applied to arylene sulfide copolymers, a problem was found in which the weight average molecular weight decreased as described below.

Patent Document 7 discloses polyarylene sulfide resin powder for thermoplastic prepreg, and describes various methods for producing resin powder, such as a method of dissolving polyarylene sulfide resin in a solvent and then spray drying it. However, the only description of a specific powder manufacturing method was dry pulverization. Furthermore, similar to the inventions described in Patent Documents 1 to 3, since the resin is in the form of pellets or lumps that are produced by heating in a molten state, there is also the problem that it is difficult to make it into fine particles by dry pulverization.

In Patent Document 8, PPS spherical fine powder is obtained, but since a thermoplastic polymer other than PPS is added, there is a problem that the chemical resistance of the fine powder decreases if the thermoplastic polymer remains, and the process There was a problem that it became complicated.

Therefore, an object of the present invention is to obtain fine particles of polyarylene sulfide copolymer having a high glass transition temperature and high molecular weight.

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 having a glass transition point measured by differential scanning calorimetry of 95° C. or more and 190° C. or less, a weight average molecular weight Mw of 30,000 or more, and a median diameter D50 of 10 μm or more and 150 μm or less. Polymer fine particles.
2. The polyarylene sulfide copolymer fine particles described in 1 above, containing at least one bonding group selected from a sulfonyl group, a sulfinyl group, an ester group, an amide group, an imide group, an ether group, a urea group, a urethane group, and a siloxane group. .
3. 1. The polyarylene sulfide copolymer fine particles described in 1 above, which have a structure in which an arylene sulfide unit and a copolymer component are connected through an imide group.
4. The polyarylene sulfide copolymer fine particles according to any one of 1 to 3 above, which have at least one structure selected from the following formulas (a) to (s) as a structural unit.

(R, R ¹ and R ² are substituents 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; ² may be the same or different.)
5. 5. The polyarylene sulfide copolymer fine particles according to any one of 1 to 4 above, which have an arylene sulfide unit having a number average molecular weight Mn of 1,000 or more and 10,000 or less as a structural unit.
6. A dispersion liquid in which the polyarylene sulfide copolymer fine particles according to any one of items 1 to 5 above are dispersed in water containing a surfactant.
7. According to any one of 1 to 5 above, the method includes the step of dissolving a polyarylene sulfide copolymer having a glass transition point of 95° C. or higher and 190° C. or lower as determined by differential scanning calorimetry in a solvent, precipitating it, and removing the solvent. A method for producing polyarylene sulfide copolymer fine particles.
8. 7. The method for producing polyarylene sulfide copolymer fine particles as described in 7 above, wherein the polyarylene sulfide copolymer is dissolved in a hydrophobic solvent.
9. 7. The method for producing polyarylene sulfide copolymer fine particles as described in 7 above, wherein the polyarylene sulfide copolymer is dissolved in a polar solvent.
10. 7. The method for producing polyarylene sulfide copolymer fine particles as described in 7 above, wherein the polyarylene sulfide copolymer is dissolved in an aprotic polar solvent.
11. 11. The method for producing polyarylene sulfide copolymer fine particles according to any one of 7 to 10 above, wherein the water content of the solvent in which the polyarylene sulfide copolymer is dissolved is 1000 ppm or less.
12. 12. The method for producing polyarylene sulfide copolymer fine particles according to any one of 7 to 11 above, wherein the polyarylene sulfide copolymer is dissolved in a solvent under normal pressure.
13. 13. The method for producing polyarylene sulfide copolymer fine particles as described in any one of 7 to 12 above, wherein the polyarylene sulfide copolymer has a loose bulk density of 0.5 g/mL or more.
14. The polyarylene sulfide copolymer has a number average molecular weight Mn of 1,000 to 10,000, and has two carboxyl groups bonded to two adjacent carbons, or an acid anhydride derived from the two carboxyl groups. at least one selected from the group consisting of amino groups, hydroxyl groups, carboxyl groups, silanol groups, sulfonic acid groups, acetamido groups, sulfonamide groups, cyano groups, isocyanate groups, aldehyde groups, acetyl groups, epoxy groups, and alkoxysilyl groups. The above polyarylene sulfide copolymer obtained by heating polyarylene sulfide (A) having two functional groups and at least one compound (B) selected from the following formulas (a') to (u'). 14. The method for producing polyarylene sulfide copolymer fine particles according to any one of 7 to 13.

(X is two carboxyl groups each bonded to two adjacent carbons, or an acid anhydride group derived from the two carboxyl groups, an amino group, a hydroxyl group, a carboxyl group, a silanol group, a sulfonic acid group, an acetamide group, At least one selected from a sulfonamide group, a cyano group, an isocyanate group, an aldehyde group, an acetyl group, an epoxy group, and an alkoxysilyl group, and R, R ¹ and R ² are hydrogen and have 1 to 12 carbon atoms. is a substituent selected from an alkyl group, an arylene group having 6 to 24 carbon atoms, and a halogen group, and R, R ¹ , and R ² may be the same or different. Also, the aromatic ring of each compound may be a di- or tri-substituted product, and the multiple substituents X substituted on one aromatic ring may be the same or different.)
15. The polyarylene sulfide copolymer has a number average molecular weight Mn of 1,000 to 10,000, and has two carboxyl groups bonded to two adjacent carbons, or an acid anhydride derived from the two carboxyl groups. polyarylene sulfide (A) having at least one functional group selected from a group and an amino group, and the substituent X is derived from two carboxyl groups each bonded to two adjacent carbons or the two carboxyl groups The polyarylene sulfide copolymer according to any one of 7 to 14 above, which is a polyarylene sulfide copolymer obtained by heating the compound (B) which is at least one selected from an acid anhydride group and an amino group. Method for producing coalesced fine particles.
16. Any one of 7 to 15 above, wherein the polyarylene sulfide copolymer is a polyarylene sulfide copolymer obtained by heating polyarylene sulfide (A) and compound (B) under substantially solvent-free conditions. A method for producing polyarylene sulfide copolymer fine particles.

According to the present invention, there are provided polyarylene sulfide copolymer fine particles having a high glass transition point, high weight average molecular weight, and a specific median diameter D50, a method for producing the same, and a dispersion of the polyarylene sulfide copolymer fine particles. I can do it.

Polyarylene sulfide copolymer fine particles and their dispersion can be used in injection molding, injection compression molding, blow molding, extrusion molding, etc. in the same way as polyarylene sulfide copolymers, as well as in the adhesive material field, paint field, polymer It can also be used as an additive to improve heat resistance in the compound field and as a raw material for three-dimensional modeling using the powder bed fusion bonding method. The modeled object has high heat resistance, excellent chemical resistance, and excellent mechanical properties derived from the characteristics of the polyarylene sulfide copolymer, and is homogeneous and sufficient due to the fact that it is modeled using fine particles. It has high density and excellent surface quality. In addition, polyarylene sulfide copolymer fine particles can be used as a resin composition by blending fillers and/or other additives, and by blending with fine particles, a more homogeneous resin composition can be made efficiently. well obtained. In particular, when blending with a fibrous inorganic filler, the polyarylene sulfide copolymer fine particles are blended more homogeneously, thereby producing a composite base material with excellent mechanical properties and a molded product containing the composite base material. I can do it.

Polyarylene sulfide copolymer fine particles, the above three-dimensional objects, and polyarylene sulfide copolymer compositions can be used for electrical/electronic parts, audio equipment parts, household and office appliance parts, machine-related parts, optical equipment, and precision machinery. It is possible to exhibit excellent heat resistance, chemical resistance, flame retardance, electrical properties, and mechanical properties in applications such as related parts, plumbing parts, automobile/vehicle-related parts, and aerospace-related parts. Become.

Embodiments of the present invention will be described in detail below.

[Polyarylene sulfide copolymer fine particles]
The lower limit of the glass transition point of the polyarylene sulfide copolymer fine particles is 95°C or higher, preferably 100°C or higher, and more preferably 110°C or higher. If the glass transition point is less than 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 raised from 0° C. to 340° C. at a rate of 20° C./min using a differential scanning calorimeter.

The crystallization temperature of the polyarylene sulfide copolymer fine particles is preferably 150°C or higher, more preferably 160°C or higher, and even more preferably 170°C or higher. Since the lower limit of the crystallization temperature is within the above range, it is easy to crystallize during molding or when manufacturing a resin composition by blending fillers and/or other additives, and has excellent mechanical properties and chemical resistance. , productivity tends to improve. Although there is no particular restriction on the upper limit of the crystallization temperature, a range of generally 235°C or lower can be exemplified. The crystallization temperature was determined by raising the temperature from 0°C to 340°C at a rate of 20°C/min using a differential scanning calorimeter, holding it at 340°C for 1 minute, and lowering the temperature to 100°C at a rate of 20°C/min. This is the value of the crystallization peak temperature detected during the test.

The polyarylene sulfide copolymer fine particles preferably have a melting point of 300°C or lower, more preferably 270°C or lower, and even more preferably 260°C or lower. When the upper limit of the melting point is within the above range, melt molding processing becomes easy. The melting point was determined using a differential scanning calorimeter by increasing the temperature from 0°C to 340°C at a rate of 20°C/min, holding it at 340°C for 1 minute, and decreasing the temperature to 100°C at a rate of 20°C/min. This is the value of the melting peak temperature detected when the temperature is maintained at 1 minute at 1 minute and the temperature is raised again to 340 0 C at a rate of 20 0 C/min.

The polyarylene sulfide copolymer forming the polyarylene sulfide copolymer fine particles is a copolymer containing 70 mol% or more of repeating units of the formula -(Ar-S)- as arylene sulfide units, preferably 80% by mole or more. It is a copolymer containing mol% or more. Examples of Ar include units represented by formulas (I) to (XI) below, among which units represented by formula (I) are particularly preferred.

(R ³ and R ⁴ are 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) group, and R ³ and R ⁴ may be the same or different.)

As long as this repeating unit is the main structural unit, a small amount of branching units or crosslinking units represented by the following formulas (XII) to (XIV) can be included. The copolymerized amount of these branching units or crosslinking units is preferably in the range of 0 to 1 mol % with respect to 1 mol of -(Ar-S)- units.

(Here, Ar is a unit represented by the above formulas (I) to (XI).)

The arylene sulfide unit may be a random copolymer, a block copolymer, or a mixture thereof containing the above repeating unit.

Typical examples of these include polyphenylene sulfide, polyphenylene sulfide sulfone, polyphenylene sulfide ketone, random copolymers and block copolymers thereof, and mixtures thereof. Particularly preferable polyarylene sulfide includes a p-phenylene sulfide unit represented by the following formula (XV) as the main constituent unit of the polymer.

Examples include polyphenylene sulfide containing 80 mol% or more, especially 90 mol% or more.

The lower limit of the number average molecular weight Mn of the arylene sulfide units of the polyarylene sulfide copolymer forming the polyarylene sulfide copolymer fine particles is preferably 1,000 or more, more preferably 1,500 or more, and still more preferably 2,000 or more. preferable. When the number average molecular weight of the arylene sulfide unit is within the above range, sufficient chemical resistance tends to be obtained. The upper limit of the number average molecular weight of the arylene sulfide units of the polyarylene sulfide copolymer forming the polyarylene sulfide copolymer fine particles is preferably 10,000 or less, more preferably 6,000 or less, and even more preferably 4,000 or less. . When the number average molecular weight of the arylene sulfide unit is within the above range, sufficient heat resistance tends to be obtained. The number average molecular weight of the arylene sulfide unit in the polyarylene sulfide copolymer can be determined by measuring the molecular weight of a residue (corresponding to the arylene sulfide unit) obtained by decomposing the bonding group described below. As a method for decomposing the bonding group, a known method depending on the type of the bonding group can be adopted. For example, when the bonding group is an imide group, a method of decomposing polyimide can be adopted, in which polyarylene sulfide copolymer fine particles are treated in an aqueous sodium hydroxide solution using the method described in JP-A No. 2006-124530. By measuring the molecular weight of the obtained residue or by the method described in JP-A-2001-163973, polyarylene sulfide copolymer fine particles are allowed to coexist with water or alcohol under high temperature and pressure of 110° C. or higher and 1 MPa or higher. By measuring the molecular weight of the residue obtained by the reaction, the molecular weight of the arylene sulfide unit can be determined. The molecular weight can be determined by measuring the molecular weight of the residue after treatment for 5 hours under reflux conditions. In order to keep the number average molecular weight of the arylene sulfide units in the polyarylene sulfide copolymer within the above range, in the production of the polyarylene sulfide copolymer, the number average molecular weight Mn is 1,000 or more and 10,000 or more, as described below. It is preferable to use the following polyarylene sulfide (A). The weight average molecular weight and number average molecular weight can be determined using, for example, SEC (size exclusion chromatography) equipped with a differential refractive index detector.

The polyarylene sulfide copolymer forming the polyarylene sulfide copolymer fine particles contains a structure derived from a copolymer component. The structure derived from the copolymer component contained in the polyarylene sulfide copolymer is exemplified by a structure containing an aromatic ring, preferably the structure shown by the above formulas (a) to (s), and more preferably the structure shown by the above formulas (a) to (s). These are structures represented by formulas (a) to (e), (i) and (j), and among them, the structure represented by formula (i) is particularly preferred. By including these structures, they tend to exhibit sufficient mechanical properties, chemical resistance, and rigidity at high temperatures.

In the polyarylene sulfide copolymer that forms the polyarylene sulfide copolymer fine particles, the arylene sulfide unit consisting of the repeating unit of -(Ar-S)- and the copolymer component are bonded to each other through a structure other than each repeating unit. The terminal groups derived from the repeating units may be directly connected to each other, but sulfonyl groups, sulfinyl groups, ester groups, amide groups, imide groups, ether groups, urea groups, urethane groups, and Preferably, they are linked by at least one bonding group selected from siloxane groups. Among these, it is more preferable to link with an imide group. By linking with imide groups, higher rigidity tends to be exhibited at high temperatures.

The lower limit of the amount of bonding groups connecting the arylene sulfide unit and the copolymerization component is preferably 1 mol% or more, more preferably 2 mol% or more, and 4 mol% or more based on the sulfur atoms in the polyarylene sulfide copolymer. is even more preferable. By setting it as the above range, it tends to be possible to sufficiently suppress a decrease in rigidity under high temperature conditions. The upper limit of the amount of bonded groups 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 amount of bonding groups increases, chemical resistance tends to decrease, but by keeping it within the above range, sufficient mechanical properties and chemical resistance tend to be exhibited. The amount of bonding groups is determined by calculation using the amount of functional groups contained in polyarylene sulfide (A), which will be described later, and the amount of functional groups contained in compound (B), which are used in the production of the polyarylene sulfide copolymer. It is also possible to determine it, and it is also possible to determine it using the FT-IR spectrum or NMR spectrum of the polyarylene sulfide copolymer fine particles.

The lower limit of the molecular weight of the polyarylene sulfide copolymer fine particles is 30,000 or more in weight average molecular weight, preferably 40,000 or more, and more preferably 50,000 or more. If the weight average molecular weight is less than 30,000, the mechanical properties of the polyarylene sulfide copolymer fine particles will be insufficient. The upper limit of the molecular weight of the polyarylene sulfide copolymer fine particles is not particularly limited, but the weight average molecular weight can be exemplified by 200,000 or less, preferably 150,000 or less, and more preferably 100,000 or less. When the upper limit of the weight average molecular weight is within the above range, the polyarylene sulfide copolymer fine particles tend to have excellent moldability. Note that the weight average molecular weight can be determined using, for example, SEC (size exclusion chromatography) using a differential refractive index detector.

The lower limit of the median diameter D50 of the polyarylene sulfide copolymer fine particles is 10 μm or more. When D50 is less than 10 μm, the bulk density becomes small and the ease of handling decreases, or because the particles are so fine that they tend to adhere to a recoater etc. in three-dimensional modeling, for example, the ease of handling decreases. The upper limit of D50 is 150 μm, preferably 100 μm or less, more preferably 70 μm or less, even more preferably 50 μm or less. If D50 exceeds 150 μm, the particle size will exceed the stacking height in three-dimensional modeling and the surface will become rough, and a homogeneous resin composition may not be obtained when a resin composition is manufactured by blending fillers and/or other additives. You may not be able to get things. The median diameter D50 is a particle size at which the cumulative frequency from the small particle size side of the particle size distribution measured by a laser diffraction particle size distribution meter is 50%. Polyarylene sulfide copolymer fine particles having a median diameter D50 of 150 μm or less can be produced by the production method described below. In addition, the median diameter D50 can be adjusted by, for example, the type of solvent in which the polyarylene sulfide copolymer is dissolved, the ratio of the polyarylene sulfide copolymer to the solvent, the cooling rate when precipitating the polyarylene sulfide copolymer, stirring, etc. can do.

The particle size distribution of the polyarylene sulfide copolymer fine particles is expressed as D90/D10, which is the ratio of D90 to D10, and is preferably 10 or less, more preferably 7 or less, further preferably 5 or less, and even more preferably 4 or less. 3 or less is even more preferable. The lower limit of D90/D10 is theoretically 1.0. When the upper limit of D90/D10 is within the above range, in three-dimensional modeling and resin composition production, differences in meltability due to differences in particle size tend to be reduced and homogeneous shaped objects and resin compositions can be obtained. . D90/D10 is the particle size (D90) at which the cumulative frequency from the small particle size side of the particle size distribution measured by the laser diffraction particle size distribution analyzer is 90%, and the cumulative frequency from the small particle size side is 10. % divided by the particle size (D10). Polyarylene sulfide copolymer fine particles having D90/D10 within the above range can be produced by the production method described below. Further, D90/D10 can be adjusted, for example, by adjusting the cooling rate, stirring, etc. when precipitating the polyarylene sulfide copolymer.

The sphericity of the polyarylene sulfide copolymer fine particles is preferably 60 or more, more preferably 70 or more. By having the lower limit of sphericity within the above range, sufficient fluidity can be obtained in three-dimensional modeling and the surface is less likely to become rough, and when manufacturing a resin composition by blending fillers and/or other additives. It tends to be blended homogeneously and a homogeneous resin composition can be obtained. Further, when polyarylene sulfide copolymer fine particles are used as a dispersion, the viscosity of the dispersion does not become too high and tends to be easy to handle. The upper limit of sphericity is theoretically 100, but from the viewpoint of increasing the surface area and making it easier to melt in three-dimensional modeling and resin composition production, it is also preferable that the sphericity is 80 or less, and 70 or less. It is also more preferable that there be. Furthermore, when polyarylene sulfide copolymer fine particles are used as a dispersion liquid, the resistance between the polyarylene sulfide copolymer fine particles and the liquid is sufficient, and the dispersion stability tends to be excellent. Sphericity is calculated by observing 30 particles at random from an optical microscope photograph and using the short axis and long axis according to the following formula.

In addition, in the formula, S: sphericity, a: major axis, b: minor axis, and n: number of measurements is 30. Polyarylene sulfide copolymer fine particles having a sphericity within the above range can be produced by the production method described below.

The lower limit of the loose bulk density of the polyarylene sulfide copolymer fine particles is preferably 0.1 g/mL or more, more preferably 0.2 g/mL or more, even more preferably 0.3 g/mL or more, and 0.4 g/mL or more. Even more preferable. When the lower limit of the loose bulk density is within the above range, handling properties tend to improve and sufficient density of the modeled object can be obtained in three-dimensional modeling. The upper limit of the loosened bulk density of fine particles is usually 0.8 g/mL or less, which improves ease of blending and homogeneous resin composition when blending fillers and/or other additives to produce a resin composition. From the viewpoint of ease of obtaining, 0.6 g/mL or less is preferable. Density refers to the mass per unit volume when powder is filled into a container. The loose bulk density can be measured by the Japanese Industrial Standards (JIS) JIS K 7365 (1999) "How to determine the apparent density of materials that can be poured from a defined funnel" or a method similar thereto. The loose bulk density is also called the coarse packing density, and is the value obtained by dividing the mass lightly packed into a certain volume by the volume. Polyarylene sulfide copolymer fine particles having a loose bulk density within the above range can be produced by the production method described below. Furthermore, the loosened bulk density can be adjusted by adjusting the median diameter D50 and D90/D10.

The upper limit of the volume average circumference of the polyarylene sulfide copolymer fine particles is preferably 450 μm or less, more preferably 300 μm or less, even more preferably 250 μm or less, even more preferably 200 μm or less, and even more preferably 150 μm or less. By having the upper limit of the volume average circumference within the above range, sufficient fluidity can be obtained in three-dimensional modeling, the surface is less likely to become rough, and a resin composition can be manufactured by blending fillers and/or other additives. In this case, it tends to be blended homogeneously and a homogeneous resin composition can be obtained. Further, when polyarylene sulfide copolymer fine particles are used as a dispersion, the viscosity of the dispersion does not become too high and tends to be easy to handle. The lower limit of the volume average peripheral length is preferably 30 μm or more. When the lower limit of the volume average circumference is within the above range, the surface area becomes large and tends to be easily melted in three-dimensional modeling or resin composition production. Furthermore, when polyarylene sulfide copolymer fine particles are used as a dispersion liquid, the resistance between the polyarylene sulfide copolymer fine particles and the liquid is sufficient, and the dispersion stability tends to be excellent. The volume average circumference can be measured using a laser diffraction particle size distribution analyzer (Microtrac MT3300EX II) manufactured by Nikkiso Co., Ltd., which takes images of particles in a dispersion flowing through a glass cell, and individually It can be calculated by analyzing images of particles. There is no particular restriction on the number of measurement counts, but from the viewpoint of accuracy of measurement results, the lower limit is 700 or more, preferably 1,000 or more, and more preferably 2,000 or more. Polyarylene sulfide copolymer fine particles having a volume average circumference within the above range can be produced by the production method described below.

[Method for producing polyarylene sulfide copolymer]
The polyarylene sulfide copolymer of the present invention comprises 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 selected from formulas (a') to (u'). It is preferable to produce by heating compound (B) (hereinafter sometimes abbreviated as compound (B)).

[Polyarylene sulfide (A)]
Polyarylene sulfide (A) is a homopolymer or copolymer whose main constituent unit is a repeating unit of the formula -(Ar-S)-. Here, the term "main structural unit" refers to containing 70 mol% or more of the repeating unit. Examples of Ar include units represented by the above formulas (I) to (XI), among which units represented by formula (I) are particularly preferred.

As long as this repeating unit is the main structural unit, a small amount of branching units or crosslinking units represented by the above formulas (XII) to (XIV) etc. can be included. The copolymerized amount of these branching units or crosslinking units is preferably in the range of 0 to 1 mol % with respect to 1 mol of -(Ar-S)- units.

The polyarylene sulfide (A) may be a random copolymer, a block copolymer, or a mixture thereof containing the above repeating units.

Typical examples of these include polyphenylene sulfide, polyphenylene sulfide sulfone, polyphenylene sulfide ketone, random copolymers and block copolymers thereof, and mixtures thereof. Particularly preferred polyarylene sulfides include polyphenylene sulfides containing 80 mol% or more, especially 90 mol% or more of p-phenylene sulfide units represented by the above formula (XV) as the main constituent units of the polymer.

Polyarylene sulfide (A) has two carboxyl groups each bonded to two adjacent carbons, or an acid anhydride group derived from the two carboxyl groups, an amino group, a hydroxyl group, a carboxyl group, and a silanol group as functional groups. , a sulfonic acid group, an acetamide group, a sulfonamide group, a cyano group, an isocyanate group, an aldehyde group, an acetyl group, an epoxy group, and an alkoxysilyl group. From the viewpoint of reactivity when heating polyarylene sulfide (A) and compound (B) described below, polyarylene sulfide (A) has an amino group as a functional group, and two carbon groups each bonded to two adjacent carbons. It is preferable to contain at least one functional group selected from a carboxyl group and an acid anhydride group derived from the two carboxyl groups. Furthermore, since it is more preferable that the combination of the functional groups of polyarylene sulfide (A) and the functional groups of compound (B) be an amino group and an acid anhydride group from the viewpoint of reactivity, polyarylene sulfide ( More preferably, A) contains an amino group and/or an acid anhydride group. In particular, from the viewpoint of ease of polymerization reaction when producing polyarylene sulfide (A) by the production method described below, it is preferable that the functional group of polyarylene sulfide (A) is an amino group, and accordingly, the compound ( The functional group of B) is preferably an acid anhydride group. The functional group of polyarylene sulfide (A) may be located in the main chain or at the end of the polyarylene sulfide, but it is better to introduce it at the end because it is more likely to react with other polymers or compounds having a functional group. It is preferable because it is easy to control, and it is also preferable from the viewpoint of performing a copolymerization reaction with compound (B) as described later. When introduced at the end, it is preferably at the p position relative to S that binds to Ar. Further, polyarylene sulfide having a functional group bonded to the above-mentioned Ar can also be exemplified as a preferable form. The above functional group has a structure derived from compound (C), and details will be described later.

The lower limit of the amount of functional groups contained in 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. When the functional group is at least the above lower limit, the glass transition point of the polyarylene sulfide copolymer tends to be sufficiently high. Moreover, 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. When the amount of functional groups is below the above upper limit, it tends to be possible to prevent the chemical resistance of the polyarylene sulfide copolymer from decreasing when producing the polyarylene sulfide copolymer described below. In addition, when the functional groups are two carboxyl groups each bonded to two adjacent carbons, the above-mentioned functional group refers to an acid anhydride group generated from two carboxyl groups each bonded to two adjacent carbons. It refers to the amount of The functional groups in polyarylene sulfide can be determined by FT-IR analysis of polyarylene sulfide, for example, the intensity of absorption at 3382 cm ^-1 derived from an amino group relative to the absorption at 1901 m ^-1 derived from a benzene ring, and the intensity of absorption at 1901 cm ^-1 derived from a benzene ring. It can be determined by comparing the intensity of the absorption at 1860 cm ⁻¹ derived from the acid anhydride group with respect to the absorption ^{at 1} .

The number average molecular weight of polyarylene sulfide (A) is 1,000 or more, preferably 2,000 or more. When the number average molecular weight of polyarylene sulfide (A) is less than 1,000, sufficient chemical resistance of the polyarylene sulfide copolymer cannot be obtained. The upper limit of the number average molecular weight of 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 polyarylene sulfide copolymer will not have sufficient heat resistance. The number average molecular weight is a value calculated in terms of polystyrene by gel permeation chromatography (GPC), which is a type of size exclusion chromatography (SEC).

The method for producing polyarylene sulfide (A) of the present invention will be specifically described below. Although not limited to the following method, in the present invention, at least a dihalogenated aromatic compound, an inorganic sulfidating agent, and compound (C) are reacted in the presence of an alkali metal hydroxide in an organic polar solvent. A preferred method for producing polyarylene sulfide is a method in which the compound (C) is present in a reaction vessel in an amount of 0.04 mol or more and 0.5 mol or less per 1 mol of the inorganic sulfidating agent. Compound (C) will be described later. In addition, when selecting two carboxyl groups each bonded to two adjacent carbons or an acid anhydride group derived from the two carboxyl groups as the functional groups contained in polyarylene sulfide (A), an organic polar It is also possible to adopt a known method for producing polyarylene sulfide in which at least a dihalogenated aromatic compound, an inorganic sulfidating agent, and a monohalogenated compound are reacted in the presence of an alkali metal hydroxide in a solvent. This is effective from the viewpoint of the reactivity of the compound, that is, the ease of introducing a functional group into polyarylene sulfide (A). Examples of the monohalogenated compound used here include 3-chlorophthalic acid and 4-chlorophthalic acid.

[Inorganic sulfidating agent]
The inorganic sulfidating agent used in the method for producing polyarylene sulfide (A) may be any agent that can introduce a sulfide bond into a dihalogenated aromatic compound, such as alkali metal sulfides, alkali metal hydrosulfides, and sulfide Examples include hydrogen.

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, with lithium sulfide and/or sodium sulfide being preferred. Sodium sulfide is more preferably used. These alkali metal sulfides can be used as hydrates or aqueous mixtures or in anhydrous form. Note that the 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. Since commonly available and inexpensive alkali metal sulfides are hydrates or aqueous mixtures, it is preferable to use alkali metal sulfides in such a form.

Specific examples of alkali metal bisulfides include lithium bisulfide, sodium bisulfide, potassium bisulfide, rubidium bisulfide, cesium bisulfide, and mixtures of two or more of these. Among them, lithium bisulfide and /Or sodium bisulfide is preferred, and sodium bisulfide is more preferably used.

Furthermore, an alkali metal sulfide prepared in a reaction system from an alkali metal hydrosulfide and an alkali metal hydroxide can also be used. Furthermore, an alkali metal sulfide prepared by contacting an alkali metal hydrosulfide and an alkali metal hydroxide in advance can also be used. These alkali metal hydrosulfides and alkali metal hydroxides can be used as hydrates or aqueous mixtures, or in anhydrous form, and hydrates or aqueous mixtures are preferred from the viewpoint of availability and cost. preferable.

Furthermore, an alkali metal sulfide prepared in a reaction system from an alkali metal hydroxide such as lithium hydroxide or sodium hydroxide and hydrogen sulfide can also be used. Alternatively, an alkali metal sulfide 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 of the following forms: gaseous, liquid, or aqueous.

[Compound (C)]
The compound (C) used in the method for producing polyarylene sulfide (A) has at least one aromatic ring, and on the one aromatic ring, an adjacent two carboxyl groups each bonded to two carbons, or an acid anhydride group derived from the two carboxyl groups, an amino group, a hydroxyl group, a carboxyl group, a silanol group, a sulfonic acid group, an acetamide group, a sulfonamide group, At least one functional group selected from a cyano group, an isocyanate group, an aldehyde group, an acetyl group, an epoxy group, and an alkoxysilyl group, and a hydroxyl group, a salt of a hydroxyl group, and a thiol that react with a dihalogenated aromatic compound in the polymerization reaction step described below. and at least one functional group selected from salts of thiol groups. From the viewpoint of reactivity when heating the polyarylene sulfide (A) and the compound (B) described below, the functional groups introduced into the polyarylene sulfide (A) are amino groups, which are bonded to two adjacent carbons, respectively. The functional group is preferably at least one functional group selected from two carboxyl groups and an acid anhydride group derived from the two carboxyl groups, and more preferably an amino group and/or an acid anhydride group. Specific examples of such compounds (C) include 2-aminophenol, 4-aminophenol, 3-aminophenol, 2-aminothiophenol, 4-aminothiophenol, 3-aminothiophenol, and 3-hydroxyphthal. Examples include acids, 4-hydroxyphthalic acid, 3-mercaptophthalic acid, 4-mercaptophthalic acid, and compounds in which the hydroxyl group or thiol group of these compounds is an alkali metal or alkaline earth metal salt. Among them, 4-aminophenol and 4-aminothiophenol can be exemplified as preferred compounds from the viewpoint of reactivity. In addition, it is also possible to use two or more different types of compounds (C) in combination, as long as they have the above characteristics. When using a compound having a hydroxyl group or a thiol group as compound (C), it is a preferred embodiment to use an equal amount of alkali metal hydroxide at the same time. In addition, when using a compound in which the hydroxyl group or thiol group is in the form of a salt as the compound (C), it is possible to form the salt in advance and then use it in the production of polyarylene sulfide, or it is possible to use it in the reaction in a reaction vessel. It is also possible to form salts.

The lower limit of the amount of compound (C) used can be exemplified by 0.01 mol or more, preferably 0.02 mol or more, more preferably 0.04 mol or more, and 0.05 mol per 1 mol of the charged inorganic sulfidating agent. The above is more preferable, 0.06 mol or more is even more preferable, 0.08 mol or more is even more preferable, and 0.1 mol or more is particularly preferable. It is preferable that the amount used be at least this value because the functional group can be sufficiently introduced into the polyarylene sulfide (A). Further, the upper limit of the amount of compound (C) to be used is 0.5 mol or less, more preferably 0.45 mol or less, and even more preferably 0.4 mol or less, per 1 mol of the charged inorganic sulfidating agent. It is preferable that the amount used be below this value, since it is possible to prevent a decrease in the molecular weight of polyarylene sulfide (A).

The timing of addition of compound (C) 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, which will be described later, or may be added in multiple steps. From the viewpoint of efficiently reacting with the dihalogenated aromatic compound, it is more preferable to add the dihalogenated aromatic compound at the same stage as the addition of the dihalogenated aromatic compound to the reaction vessel.

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

The lower limit of the amount of the dihalogenated aromatic compound to be used is not particularly limited, but it is preferable that the [monomer ratio] expressed by the following formula is 0.8 or more, more preferably 0.9 or more, and 0. More preferably, it is .95 or more. Setting the [monomer ratio] within the above range is preferable because the polymerization reaction system can be stabilized and side reactions can be prevented. Further, although there is no particular restriction on the upper limit of the amount used, it is preferable that the [monomer ratio] be 1.2 or less, more preferably 1.1 or less, and even more preferably 1.05 or less. Setting the [monomer ratio] within the above range is preferable because the amount of halogen remaining in the polyarylene sulfide can be reduced. In addition, in the following formula, [amount of dihalogenated aromatic compound], [amount of inorganic sulfidating agent], and [amount of compound (C) material] indicate the amount of each compound used when producing polyarylene sulfide. .
[Monomer ratio] = [Amount of dihalogenated aromatic compound] / ([Amount of inorganic sulfidating agent] + [Amount of compound (C) material])

[Organic polar solvent]
As the organic polar solvent used in the method for producing polyarylene sulfide of the present invention, an organic amide solvent can be preferably exemplified. 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, 1, Aprotic organic solvents such as 3-dimethyl-2-imidazolidinone, N,N-dimethylacetamide, N,N-dimethylformamide, hexamethylphosphoric acid triamide, etc., and mixtures thereof, have high reaction stability. Preferably used for Among these, N-methyl-2-pyrrolidone and 1,3-dimethyl-2-imidazolidinone are preferred, and N-methyl-2-pyrrolidone is more preferably used.

The amount of the 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 1 mol of the charged inorganic sulfidating agent. It is preferable that the amount used be at least this value because polyarylene sulfide can be synthesized with good yield. Further, the amount of the 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 1 mol of the charged inorganic sulfidating agent. It is preferable that the amount used be at most this value because gas generated when the resulting polyarylene sulfide is heated can be reduced.

[Polymerization aid]
One of the preferred embodiments is to use a polymerization aid in order to obtain polyarylene sulfide with a relatively high degree of polymerization in a shorter time. Here, the term "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 oxides. Examples include similar 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, and the organic carboxylates are preferably alkali metal carboxylates, and the alkali metal chlorides are lithium chloride.

The alkali metal carboxylate has 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; n is an integer from 1 to 3). Alkali metal carboxylates can also be used as hydrates, anhydrides or aqueous solutions. Specific examples of alkali metal carboxylates include lithium acetate, sodium acetate, potassium acetate, sodium propionate, lithium valerate, sodium benzoate, and mixtures thereof.

An alkali metal carboxylate is produced by adding approximately equal chemical equivalents of an organic acid and one or more compounds selected from the group consisting of alkali metal hydroxides, alkali metal carbonates, and alkali metal bicarbonates and reacting them. It may be synthesized by Among the alkali metal carboxylates mentioned above, lithium salts have high solubility in the reaction system and have a large auxiliary effect, but are expensive. On the other hand, since potassium, rubidium, and cesium salts are thought to have insufficient solubility in the reaction system, sodium acetate, which is inexpensive and has appropriate solubility in the polymerization system, is most preferably used.

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 1 mol of the charged inorganic sulfidating agent, and in the sense of obtaining a higher degree of polymerization, The range is preferably from 0.1 mol to 0.6 mol, and more preferably from 0.2 mol to 0.5 mol.

In addition, when water is used as a polymerization aid, the amount added is usually in the range of 0.3 to 15 mol per 1 mol of the inorganic sulfidating agent, and 0.6 mol to obtain a higher degree of polymerization. The range is preferably from 1 mol to 10 mol, and more preferably from 1 mol to 5 mol.

It is of course possible to use two or more of these polymerization aids in combination. For example, when an alkali metal carboxylate and water are used together, it is possible to increase the molecular weight with a smaller amount of the alkali metal carboxylate and water.

There is no particular specification regarding the timing of addition of these polymerization aids, and they may be added at any time during the pre-step, at the start of polymerization, or during the polymerization reaction step, which will be described later, or may be added in multiple portions. When using an alkali metal carboxylate as a polymerization aid, it is more preferable to add it simultaneously with other additives at the start of the previous step or at the start of polymerization, from the viewpoint of ease of addition. Furthermore, when water is used as a polymerization aid, it is effective to add it during the polymerization reaction step after charging the dihalogenated aromatic compound.

[Polymerization stabilizer]
A polymerization stabilizer can also be used to stabilize the polymerization reaction system and prevent side reactions. The polymerization stabilizer contributes to stabilizing the polymerization reaction system and suppresses undesirable side reactions. One indicator of side reactions is the production of thiophenol. The production of thiophenol can be suppressed by adding a polymerization stabilizer. 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 above-mentioned alkali metal carboxylates also act as polymerization stabilizers, and are therefore included as polymerization stabilizers. Furthermore, when using an alkali metal hydrosulfide as an inorganic sulfidating agent, it is particularly preferable to use an alkali metal hydroxide at the same time. Hydroxides can also serve as polymerization stabilizers.

These polymerization stabilizers can be used alone or in combination of two or more. The polymerization stabilizer is 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 inorganic sulfidating agent charged. Preferably, they are used in molar proportions. If this proportion is too small, the stabilizing effect will be insufficient, and if it is too large, it will be economically disadvantageous, and the polymer yield will tend to decrease.

The timing of adding the polymerization stabilizer is not particularly specified, and it may be added at any time during the pre-process, at the start of polymerization, or during the polymerization reaction step, which will be described later, or may be added in multiple steps. It is more preferable to add it simultaneously at the start of the previous step or at the start of polymerization because it is easy.

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

[pre-process]
In the method for producing polyarylene sulfide (A), the inorganic sulfidating agent is usually used in the form of a hydrate, but before adding the dihalogenated aromatic compound, an organic polar solvent and an inorganic sulfidating agent are added. It is preferable to raise the temperature of the mixture and remove excess water from the system.

In addition, as mentioned above, inorganic sulfidating agents that are prepared from alkali metal hydrosulfides and alkali metal hydroxides in situ in the reaction system or in a tank different from the polymerization tank can also be used. Can be used. Although there are no particular limitations on this method, it is preferable to add an alkali metal hydrosulfide and an alkali metal hydroxide to an organic polar solvent under an inert gas atmosphere at a temperature ranging from room temperature to 150°C, preferably from room temperature to 100°C. In addition, there is a method in which the temperature is raised to at least 150°C or higher, preferably 180°C to 260°C, under normal pressure or reduced pressure, and water is distilled off. A polymerization aid may be added at this stage, or the compound (C) may be added in advance. Further, in order to promote distillation of water, toluene or the like may be added to carry out the reaction.

The amount of water in the system at the end of the previous step, that is, before the polymerization reaction step, is preferably 0.3 mol to 10.0 mol per mol of the sulfidating agent charged. Here, the amount of water within the system is the amount obtained by subtracting the amount of water removed from the polymerization system from the amount of water charged into the polymerization system. Further, the water to be charged may be in any form such as water, an aqueous solution, or crystal water.

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

When starting the polymerization reaction step, the organic polar solvent, sulfidating agent, and dihalogenated aromatic compound are mixed at a temperature range of room temperature to 240°C, preferably 100°C to 230°C, preferably under an inert gas atmosphere. do. Compound (C) and a polymerization aid may be added at this stage. These raw materials may be added in any order or at the same time.

The mixture is heated to a temperature typically in the range of 200°C to less than 290°C. Although there is no particular restriction on the heating rate, 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 preferable.

Generally, the temperature is finally raised to a temperature of 250° C. to less than 290° C., and the reaction is carried out at that temperature for usually 0.25 hours to 50 hours, preferably 0.5 hours to 20 hours.

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 below 270° C. to 290° C. is effective in obtaining a higher degree of polymerization. At this time, the reaction time at 200° C. to 260° C. is usually selected in the range of 0.25 hours to 20 hours, preferably in the range of 0.25 hours to 10 hours.

In addition, in order to adjust the molecular weight of the polymer, it is possible to add compound (C) during the polymerization, but from the viewpoint of efficient reaction of compound (C), at least a part of compound (C) is added. More preferably, it is added at the same stage as the dihalogenated aromatic compound.

[Collection process]
In the method for producing polyarylene sulfide (A), after completion of polymerization, solid matter is recovered from the polymerization reaction product containing the polymer, solvent, and the like. As for the recovery method, any known method may be employed.

For example, a method may be used in which after the polymerization reaction is completed, the particulate polymer is recovered by slow cooling. There is no particular limit to the slow cooling rate at this time, but it is usually about 0.1°C/min to 3°C/min. It is not necessary to perform slow cooling at the same speed throughout the slow cooling process; slow cooling is performed at a rate of 0.1°C/min to 1°C/min until the polymer particles crystallize and precipitate, and then at a speed of 1°C/min or more. method etc. may be adopted.

Also, one of the preferable methods is to perform the above-mentioned recovery under quenching conditions. Among these recovery methods, a preferred method is the flash method. In the flash method, the polymerization reaction product is flashed from a high temperature and high pressure state (usually 250°C or higher, 8kg/cm2 ^or higher) into an atmosphere of normal pressure or reduced pressure, and the polymer is recovered in powder form at the same time as the solvent is recovered. It's a method. The term "flash" as used herein means that the polymerization reaction product is ejected from a nozzle. Specific examples of the flashing atmosphere include nitrogen or water vapor at normal pressure, and the temperature is usually selected from a range of 150°C to 250°C.

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

The case of acid treatment is as follows. The acid used in the acid treatment is not particularly limited as long as it does not have the effect of decomposing polyarylene sulfide (A), and examples include acetic acid, hydrochloric acid, sulfuric acid, phosphoric acid, silicic acid, carbonic acid, and propylic acid. Among them, acetic acid and hydrochloric acid are more preferably used. On the other hand, those that decompose and deteriorate polyarylene sulfide (A), such as nitric acid, are not preferred. A method for acid treatment includes, for example, a method of immersing polyarylene sulfide (A) in an acid or an aqueous solution of an acid, and it is also possible to stir or heat the polyarylene sulfide (A) if necessary. When using an acid solution, the solution may be a solution using an organic solvent or an aqueous solution, but from the viewpoint of the miscibility of the acid and the tendency for the solubility of salts and basic components contained in polyarylene sulfide to be relatively high, An aqueous solution is preferable, and the water used is preferably distilled water or deionized water so as not to impair the desired effect of chemical modification of polyarylene sulfide. For example, when using acetic acid, a sufficient effect can be obtained by immersing polyarylene sulfide (A) powder in an acetic acid aqueous solution of pH 4 heated to 80° C. to 200° C. and stirring for 30 minutes. The pH after treatment may be 4 or more, for example, about pH 4 to 8. In order to remove residual acids or salts from 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 preferable chemical modification effect of polyarylene sulfide (A). Acid treatment is preferred because it tends to yield a polyarylene sulfide copolymer with a higher molecular weight when polyarylene sulfide (A) is used to obtain a polyarylene sulfide copolymer.

When performing hot water treatment, the procedure is 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, particularly preferably 170°C or higher. If the temperature is lower than 100° C., the effect of the preferred chemical modification of polyarylene sulfide is undesirable. In order to achieve the desired effect of chemical modification of polyarylene sulfide (A) by hot water treatment, the water used is preferably distilled water or deionized water. There are no particular restrictions on the operation of hot water treatment. This can be carried out by adding a predetermined amount of polyarylene sulfide (A) to a predetermined amount of water, heating and stirring the mixture in a pressure vessel, or continuously subjecting it to hot water treatment. As for the ratio of polyarylene sulfide (A) to water, the more water the better, but usually the bath ratio is 200g or less of polyarylene sulfide (A) per 1 liter of water (based on the weight of dry polyarylene sulfide (A)). washing liquid weight) is selected. Further, in order to avoid undesirable decomposition of the terminal reactive functional group, it is desirable that the treatment atmosphere be an inert atmosphere. Furthermore, in order to remove remaining components, it is preferable to wash the polyarylene sulfide (A) after this hot water treatment several times with warm water.

When washing with an organic solvent, the procedure is as follows. The organic solvent used for washing polyarylene sulfide (A) is not particularly limited as long as it does not have the effect of decomposing polyarylene sulfide. For example, 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; halogen solvents such as chloroform, methylene chloride, trichloroethylene, ethylene dichloride, and perchlorethylene; methanol, ethanol, propanol, butanol, pentanol, ethylene glycol, and propylene. Alcohol solvents such as glycol and aromatic hydrocarbon solvents such as benzene, toluene, and xylene are examples of organic solvents used for washing the polyarylene sulfide (A). Among these organic solvents, N-methyl-2-pyrrolidone, acetone, dimethylformamide and chloroform are preferably used. Furthermore, from the viewpoint of removing impurities having an arylene sulfide structure, N-methyl-2-pyrrolidone, dimethylformamide, and chloroform, which are nitrogen-containing polar solvents that tend to provide relatively high solubility, are particularly preferred. These organic solvents may be used alone or in combination of two or more, or may be used in combination with water. As a method for washing with an organic solvent, for example, there is a method in which polyarylene sulfide (A) is immersed in an organic solvent, and it is also possible to stir or heat as appropriate, if necessary. There is no particular restriction on the washing temperature when washing polyarylene sulfide (A) with an organic solvent, and any temperature from room temperature to about 300°C can be selected. Although the higher the cleaning temperature, the higher the cleaning efficiency tends to be, usually a cleaning temperature of room temperature to 150° C. can be sufficiently effective. It is also possible to wash under pressure in a pressure vessel at a temperature above the boiling point of the organic solvent. Furthermore, there is no particular restriction on the cleaning time. Although it depends on the cleaning conditions, in the case of batch cleaning, sufficient effects can usually be obtained by cleaning for 5 minutes or more. It is also possible to wash continuously. The organic solvent reduces the amount of gas generated when polyarylene sulfide (A) is heated, and also makes it easier to form a high molecular weight product when polyarylene sulfide (A) is used to obtain the polyarylene sulfide copolymer described below. This is preferable because it tends to be obtained.

[Thermal oxidation crosslinking treatment]
Polyarylene sulfide (A) can also be used after the molecular weight is increased by thermal oxidative crosslinking treatment by heating in an oxygen atmosphere or heating with addition of a crosslinking agent such as peroxide after completion of polymerization. However, the number average molecular weight of polyarylene sulfide (A) is preferably 10,000 or less.

[Compound (B)]
Compound (B) is at least one selected from the above formulas (a') to (u'), and X is derived from two carboxyl groups bonded to two adjacent carbons or those two carboxyl groups. From acid anhydride groups, amino groups, hydroxyl groups, carboxyl groups, silanol groups, sulfonic acid groups, acetamido groups, sulfonamide groups, cyano groups, isocyanate groups, aldehyde groups, acetyl groups, epoxy groups, and alkoxysilyl groups. At least one is selected. R, R ¹ and R ² are substituents 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; may be the same or different. Hydrogen, methyl group, ethyl group, or propyl group is preferred from the viewpoint of easy availability. Further, the aromatic ring of each compound may be a di-substituted or tri-substituted compound, and the plurality of substituents X substituted on one aromatic ring may be the same or different. From the viewpoint of reactivity when heating the aforementioned polyarylene sulfide (A) and compound (B), compound (B) has an amino group as a functional group and two carboxyl groups each bonded to two adjacent carbons. , and an acid anhydride group derived from the two carboxyl groups. Furthermore, from the viewpoint of reactivity, it is more preferable that the combination of the functional groups of polyarylene sulfide (A) and the functional groups of compound (B) be an amino group and an acid anhydride group. more preferably contains an amino group and/or an acid anhydride group. In particular, from the viewpoint of ease of polymerization reaction when producing polyarylene sulfide (A) by the above-mentioned production method, it is preferable that the functional group of polyarylene sulfide (A) is an amino group, and accordingly, the compound ( The functional group of B) is preferably an acid anhydride group.

Specific examples of 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, pyromellitic anhydride, 3,3',4,4'-thiodiphthalic anhydride, 3,3',4,4' -Sulfonyl diphthalic anhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 3,3',4,4'-sulfinyl diphthalic anhydride, 3,3',4, 4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-tetracarboxyldiphenylmethane dianhydride, 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride, naphthalene-1 , 4,5,8-tetracarboxylic dianhydride, glycerin bisanhydrotrimellitate monoacetate, ethylene glycol bisanhydrotrimellitate, 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' -Sulfinyl dibenzoic acid, 4,4'-dicarboxylbiphenyl, p-phenylenediamine, 4,4'-diaminodiphenylsulfide, 4,4'-diaminodiphenylsulfone, 4,4'-diaminobenzophenone, 4,4' - Diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 2,7-diaminofluorene, o-toluidine, 1,5-diaminonaphthalene, p-benzenediol, 4,4'-dihydroxydiphenyl sulfide, 4,4'-dihydroxy Diphenylsulfone, 4,4'-dihydroxybenzophenone, 4,4'-dihydroxydiphenylmethane, 4,4'-dihydroxydiphenyl ether, 2,7-dihydroxyfluorene, 4,4'-dihydroxybiphenyl, 1,5-dihydroxynaphthalene, From the viewpoint of reactivity, 3,3',4,4'-thiodiphthalic anhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 3,3',4,4' -Sulfinyl diphthalic anhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride, 4,4'- Thiodibenzoic acid, 4,4'-dicarboxylbenzophenone, 4,4'-sulfinyl dibenzoic acid, 4,4'-dicarboxylbiphenyl, pyromellitic acid, pyromellitic anhydride, 4,4'-diaminodiphenylsulfone , 4,4'-diaminobenzophenone, and 2,7-diaminofluorene are preferably used.

[Heating conditions for polyarylene sulfide (A) and compound (B)]
The polyarylene sulfide copolymer can be produced by heating polyarylene sulfide (A) and compound (B) having a number average molecular weight Mn of 1,000 or more and 10,000 or less.

The ratio of the amount of functional groups derived from the compound (B)/the amount of functional groups derived from the polyarylene sulfide (A) is preferably 0.75 or more and 1.25 or less. Within this range, the resulting polyarylene sulfide copolymer tends to have a high molecular weight and exhibit sufficient mechanical properties and chemical resistance.

Polyarylene sulfide (A) and compound (B) may be heated by mixing the entire amount from the beginning, or by heating at least a portion of polyarylene sulfide (A) and at least a portion of compound (B). After mixing and heating, the remaining polyarylene sulfide (A) and/or compound (B) may be mixed and heated. In the latter case, after mixing and heating at least a portion of polyarylene sulfide (A) and at least a portion of compound (B), the remaining polyarylene sulfide (A) and/or compound (B) are subsequently mixed. Alternatively, after mixing and heating at least a portion of polyarylene sulfide (A) and at least a portion of compound (B), the product may be taken out and then the remaining polyarylene sulfide ( A) and/or compound (B) may be mixed and heated. 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 easy control and adjustment of the thermal properties of polyarylene sulfide copolymers such as glass transition point, crystallization temperature, melting point, molecular weight, terminal species and their amount depending on the application, polyarylene sulfide copolymers are After mixing and heating at least a portion of the arylene sulfide (A) and at least a portion of the compound (B), mixing and heating the remaining polyarylene sulfide (A) and/or the compound (B). is preferred.

An example of the lower limit of the heating temperature is 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 to such a range, the reaction between polyarylene sulfide (A) and compound (B) can be easily promoted, and the temperature at which polyarylene sulfide (A) melts or higher can be easily promoted. This tends to allow the reaction to be completed in a shorter time. The temperature at which polyarylene sulfide (A) melts varies depending on the composition and molecular weight of polyarylene sulfide (A), as well as the environment during heating, so it cannot be uniquely indicated. ) can be determined by analyzing it with a differential scanning calorimeter. An example of the upper limit of the heating temperature is 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 the polyarylene sulfide (A) can be suppressed, and the resulting polyarylene sulfide copolymer can be It tends to suppress the deterioration of characteristics.

The heating time cannot be specified uniquely because it changes depending on the composition and molecular weight of polyarylene sulfide (A) and the environment during heating, but it is set so that the above-mentioned undesirable side reactions occur as little as possible. It is preferable. The lower limit of the heating time is, 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 to such a range, the reaction between polyarylene sulfide (A) and compound (B) can proceed more fully. The upper limit of the heating time is, for example, within 100 hours, preferably within 20 hours, more preferably within 10 hours, and even more preferably within 1 hour. By setting the upper limit of the heating time within this range, it is highly economical and tends to avoid the aforementioned undesirable side reactions.

Heating can be carried out in the absence of a solvent or in the presence of a solvent. When carrying out in the presence of a solvent, there are no particular limitations on the solvent as long as it does not substantially cause undesirable side reactions such as decomposition and 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 reaction substantially without solvent. Further, when molding the obtained polyarylene sulfide copolymer, it is preferable to carry out the molding under substantially solvent-free conditions, also from the viewpoint of preventing contamination of the molded product by generated gas. Here, the term "substantially solvent-free conditions" means that the amount of solvent in the system for heating polyarylene sulfide (A) and compound (B) is 10% by weight or less, preferably 3% by weight or less.

Heating in the method for producing the polyarylene sulfide copolymer of the present invention may be carried out not only by a method using a normal polymerization reaction apparatus, but also in a mold for producing a molded article, by an extruder or by melting. This can be carried out without any particular restriction as long as it is carried out using a device equipped with a heating mechanism, such as using a kneader, and known methods such as a batch method or a continuous method can be employed.

The atmosphere during heating is preferably a non-oxidizing atmosphere, and it is also preferable to conduct the heating under reduced pressure conditions. In addition, when carrying out the reaction under reduced pressure conditions, it is preferable that the atmosphere in the reaction system is once made into a non-oxidizing atmosphere and then changed to reduced pressure conditions. This tends to suppress undesirable side reactions such as crosslinking reactions and decomposition reactions between the polyarylene sulfide (A) and between the polyarylene sulfide copolymers produced. Note that a non-oxidizing atmosphere is 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 does not substantially contain oxygen, that is, an inert gas atmosphere such as nitrogen, helium, or argon. Of these, a nitrogen atmosphere is particularly preferred from the viewpoint of economy and ease of handling. Further, the term "reduced pressure condition" means that the pressure inside the reaction system is lower than atmospheric pressure, and the upper limit of the pressure is preferably 50 kPa or less, more preferably 20 kPa or less, and even more preferably 10 kPa or less. By setting the upper limit of the pressure within such a range, undesirable side reactions such as crosslinking reactions tend to be suppressed. An example of the 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 loading the reaction apparatus due to unnecessarily reduced pressure.

[Method for producing polyarylene sulfide copolymer fine particles]
Polyarylene sulfide copolymer fine particles can be produced by dissolving a polyarylene sulfide copolymer in a solvent, causing precipitation, and removing the solvent.

There is no particular restriction on the form of the raw material polyarylene sulfide copolymer, and examples include powder, pellets, fibers, films, molded products, and granules. Dry pulverization, wet pulverization, and frozen pulverization using jet mills, bead mills, hammer mills, ball mills, cutter mills, stone mills, etc. are generally known as methods for atomizing resin. When using pellets or molded products as raw materials, there are problems such as insufficient micronization, making it impossible to obtain fine particles with the desired particle size, and the need for long pulverization, which reduces economic efficiency and productivity. occurs. However, with this method, even when pellets or molded products are used as raw materials, it is possible to easily form them into fine particles. Note that the difference in form between pellets and powder or granules can be expressed by bulk density, and in the present invention, the form of pellets is indicated by a loose bulk density value of 0.5 g/mL or more. In the method for producing polyarylene sulfide copolymer fine particles of the present invention, it is preferable to use a polyarylene sulfide copolymer having a loose bulk density of 0.5 g/mL or more.

The lower limit of the glass transition point of the polyarylene sulfide copolymer used to produce the polyarylene sulfide copolymer fine particles of the present invention is 95°C or higher, preferably 100°C or higher, and more preferably 110°C or higher. If the glass transition point is less than 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, chemical resistance will be insufficient. The glass transition point may change when measured as a polyarylene sulfide copolymer and when measured as a polyarylene sulfide copolymer fine particle depending on the conditions for producing the polyarylene sulfide copolymer fine particle.

The lower limit of the molecular weight of the polyarylene sulfide copolymer used for producing the polyarylene sulfide copolymer fine particles of the present invention is preferably 30,000 or more in terms of weight average molecular weight, more preferably 40,000 or more, and 50,000 or more. The above is more preferable. When the weight average molecular weight is 30,000 or more, sufficient mechanical properties of the polyarylene sulfide copolymer fine particles tend to be obtained. The upper limit of the molecular weight of the polyarylene sulfide copolymer fine particles is not particularly limited, but the weight average molecular weight can be exemplified by 200,000 or less, preferably 150,000 or less, and more preferably 100,000 or less. When the upper limit of the weight average molecular weight is within the above range, the polyarylene sulfide copolymer fine particles tend to have excellent moldability. The weight average molecular weight may vary depending on the conditions for producing the polyarylene sulfide copolymer fine particles when measured as a polyarylene sulfide copolymer and when measured as a polyarylene sulfide copolymer fine particle. The degree can be evaluated by the Mw retention rate obtained by dividing the weight average molecular weight of the polyarylene sulfide copolymer fine particles by the molecular weight of the polyarylene sulfide copolymer used for production. The Mw retention rate is preferably 50% or more, more preferably 60% or more, and even more preferably 80% or more. Setting the Mw retention rate within the above range is preferable because the mechanical properties of the polyarylene sulfide copolymer fine particles can be maintained high. There is no particular limit to the upper limit of the Mw retention rate, but it is usually 100% or less. As described below, the Mw retention rate changes depending on the stability of the polyarylene sulfide copolymer when it is dissolved in a solvent during the dissolution process, so it is adjusted depending on the type of solvent used and the water content. be able to.

[Dissolution process]
Examples of the solvent for dissolving the polyarylene sulfide copolymer include N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-cyclohexyl-2-pyrrolidone, N-methyl-ε-caprolactam, N,N -dimethylformamide, N,N-dimethylacetamide, 1,3-dimethyl-2-imidazolidinone, hexamethylphosphoric triamide, 3-methoxy-N,N-dimethylpropanamide, 1,3-dimethyl-2-imidazo Nitrogen-containing polar solvents such as lysinone and 2-hydroxy-N,N-dimethylpropanamide, sulfoxide/sulfone solvents such as dimethylsulfoxide, dimethylsulfone, and diphenylsulfone, and ketones such as acetone, methyl ethyl ketone, diethyl ketone, acetophenone, and benzophenone. Ether solvents such as dimethyl ether, diethyl ether, dipropyl ether, tetrahydrofuran, and diphenyl ether; alcohols such as methanol, ethanol, propanol, butanol, pentanol, isopropanol, ethylene glycol, propylene glycol, phenol, cresol, and polyethylene glycol; Phenol solvent, chloroform, bromoform, dichloromethane, 1,2-dichloroethane, 1,1,1-trichloroethane, 1,1,2,2-tetrachloroethane, chlorobenzene, o-dichlorobenzene, p-dichlorobenzene, 2,6 Examples include halogen solvents such as dichlorotoluene, 1-chloronaphthalene and hexafluoroisopropanol, aromatic hydrocarbon solvents such as benzene, toluene and xylene, and water.

Among these, from the viewpoint of stability of the polyarylene sulfide copolymer when the polyarylene sulfide copolymer is dissolved, it is recommended to use a hydrophobic solvent as a solvent type that is unlikely to cause water miscibility, moisture absorption, or water absorption. preferable. The term "hydrophobic solvent" refers to a solvent having a dielectric constant of 6.0 or less. Examples of preferred hydrophobic solvents include aromatic hydrocarbon solvents, chloroform, diethyl ether, 1-chloronaphthalene, benzophenone, diphenylsulfone, diphenyl ether, and the like.

From the viewpoint of solubility of the polyarylene sulfide copolymer, it is also possible to use a polar solvent as the solvent type. A polar solvent refers to a solvent having a relative dielectric constant of more than 6.0. Examples of polar solvents include N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-cyclohexyl-2-pyrrolidone, N-methyl-ε-caprolactam, N,N- as an aprotic polar solvent. Dimethylformamide, N,N-dimethylacetamide, 1,3-dimethyl-2-imidazolidinone, hexamethylphosphoric acid triamide, 3-methoxy-N,N-dimethylpropanamide, 1,3-dimethyl-2-imidazolidinone Examples include non, dichloromethane, tetrahydrofuran, ethyl acetate, acetone, acetonitrile, dimethyl sulfoxide, and dimethyl sulfone. Further, examples of the protic polar solvent include 2-hydroxy-N,N-dimethylpropanamide and alcohol solvents. The polyarylene sulfide copolymer has relatively high stability when dissolved, and from the viewpoint that it is easy to obtain high molecular weight polyarylene sulfide copolymer fine particles, aprotic polar solvents are particularly suitable. preferable.

In addition, regardless of whether a hydrophobic solvent or a polar solvent is used, from the viewpoint of stability of the polyarylene sulfide copolymer when the polyarylene sulfide copolymer is dissolved, it is important that the water content of the solvent is low. preferable. The upper limit of the water content of the solvent is preferably 1000 ppm or less, more preferably 500 ppm or less, and even more preferably 100 ppm or less. The lower limit of the water content of the solvent is theoretically zero. The water content of a solvent can be determined using the Karl Fischer method, and can also be determined from an inspection report.

From the viewpoint of the above water content, the ratio of polyarylene sulfide copolymer to solvent is not particularly limited as long as the polyarylene sulfide copolymer is dissolved, but the lower limit of the ratio is It is preferable that the amount of the copolymer is 0.1 part by weight or more from the viewpoint of economy and productivity. In addition, from the viewpoint of relatively reducing the water content with respect to the amount of polyarylene sulfide copolymer, it is preferable that the lower limit of the ratio is 1 part by weight or more of polyarylene sulfide copolymer per 100 parts by weight of solvent. The amount is preferably 5 parts by weight or more, even more preferably 10 parts by weight or more, and even more preferably 20 parts by weight or more. From the viewpoint of ensuring solubility, the upper limit of the ratio can be exemplified as a preferable range of 100 parts by weight or less of the polyarylene sulfide copolymer per 100 parts by weight of the solvent, more preferably 50 parts by weight or less, and 20 parts by weight or less. More preferred.

In order to dissolve the polyarylene sulfide copolymer, it is preferable to heat the polyarylene sulfide copolymer and the solvent. The required heating temperature varies depending on the molecular weight, structure, concentration, solvent type, etc. of the polyarylene sulfide copolymer, but is usually preferably 180°C or higher, more preferably 200°C or higher, even more preferably 220°C or higher, and 240°C or higher. is even more preferable. The upper limit is preferably 400°C or lower, more preferably 320°C or lower, from the viewpoint of suppressing decomposition of the polyarylene sulfide copolymer. There is no particular restriction on the heating rate.

The heating time varies depending on the solubility based on the molecular weight, structure, concentration, solvent type, heating temperature, etc. of the polyarylene sulfide copolymer, but it is usually 5 minutes or more to fully dissolve the polyarylene sulfide copolymer. is preferable, 10 minutes or more is more preferable, and even more preferably 15 minutes or more. The upper limit of the heating time is usually preferably within 10 hours, more preferably within 5 hours, even more preferably within 2 hours, from the viewpoint of suppressing decomposition of the polyarylene sulfide copolymer and from the viewpoints of economy and productivity. Within 1 hour is even more preferable.

The atmosphere during heating is preferably a non-oxidizing atmosphere from the viewpoint of preventing deterioration of the polyarylene sulfide copolymer. A non-oxidizing atmosphere is an atmosphere in which the oxygen concentration in the gas phase is 5% by volume or less, preferably 2% by volume or less, more preferably substantially no oxygen, that is, an inert gas atmosphere such as nitrogen, helium, or argon. Of these, a nitrogen atmosphere is particularly preferred from the viewpoint of economy and ease of handling.

For the purpose of increasing the solubility of the polyarylene sulfide copolymer in the solvent, it is also preferable to heat the solvent under pressure so that the solvent can be heated to a temperature equal to or higher than its boiling point. The pressure at that time varies depending on the solubility of the polyarylene sulfide copolymer, the type of solvent, the heating temperature, the volume of the container, etc., and may be 1 MPa or more. An example of the upper limit of the pressure is 100 MPa or less from the viewpoint of ease of implementation, preferably 10 MPa or less, and more preferably 5 MPa or less.

Furthermore, for the purpose of reducing the water content of the solvent, it is also preferable to heat under normal pressure, which does not prevent volatilization of water. The atmosphere at that time is preferably the above-mentioned non-oxidizing atmosphere, and heating is preferably performed under a nitrogen stream.

Although stirring is not essential when dissolving the polyarylene sulfide copolymer, stirring is preferably performed from the viewpoint of shortening the time required for dissolving the polyarylene sulfide copolymer.

[Precipitation process]
After the dissolution step, polyarylene sulfide copolymer fine particles are precipitated from the polyarylene sulfide copolymer solution. There are no particular limitations on the method of precipitation, but examples include a method of cooling by controlling heating and controlling the rate of temperature drop, a method of stopping heating and cooling, and a method of rapidly cooling by bringing the container into contact with a refrigerant. In addition, the polyarylene sulfide copolymer solution under heat and pressure is transferred by ejecting it into another container whose temperature is below the boiling point of the solvent used for dissolution and below the pressure during heating, and the cooling effect due to the pressure difference is achieved. Rapid cooling is also possible by utilizing the cooling effect of latent heat. Alternatively, the polyarylene sulfide copolymer solution may be heated above its boiling point at normal pressure and then ejected into an atmosphere at normal pressure or reduced pressure to instantaneously vaporize and distill off the solvent to precipitate it. Although stirring during cooling is not essential when precipitating by cooling, stirring is preferably performed in order to control the particle size and particle size distribution of the polyarylene sulfide copolymer fine particles. The cooling rate when cooling the container is preferably 0.1°C/min or more, more preferably 1°C/min or more, and 5°C/min or more from the viewpoint of easily obtaining polyarylene sulfide copolymer fine particles with a smaller D50. More preferably, the time is more than 1 minute. Although the upper limit of the cooling rate depends on the container size, an example of a normal range is 20° C./min or less.

[Solvent removal process]
The solvent is removed from the dispersion that has been cooled to precipitate polyarylene sulfide copolymer particles, and the polyarylene sulfide copolymer particles are recovered. As a method for removing the solvent and recovering the polyarylene sulfide copolymer fine particles, conventionally known methods can be employed, such as filtration, centrifugation, centrifugal filtration, heat drying, spray drying, decantation, etc. .

In particular, when using a solvent that becomes solid at room temperature, it is preferable to perform hot filtration between the temperature at which the polyarylene sulfide copolymer fine particles precipitate and the temperature at which the solvent solidifies.

In addition, the recovered polyarylene sulfide copolymer fine particles were subjected to hot water treatment and washing with an organic solvent as described in the post-treatment step in the method for producing polyarylene sulfide (A) in order to remove the solvent used for dissolution. It is possible to apply

[Polyarylene sulfide copolymer fine particle dispersion]
The obtained polyarylene sulfide copolymer fine particles can be used as fine particles or as a dispersion in a solvent. The solvent used in the above-mentioned dissolution process can also be used as a dispersion medium for the polyarylene sulfide copolymer fine particle dispersion, but from the environmental and safety aspects and the versatility of the dispersion, water is the most suitable dispersion medium. preferable.

When used as a dispersion in water, it is preferable to add a surfactant to improve dispersibility in water.

Examples of the surfactant include cationic surfactants, anionic surfactants, amphoteric surfactants, and nonionic surfactants. Examples of anionic surfactants include sodium fatty acid, potassium fatty acid, sodium alkylbenzene sulfonate, sodium alkyl sulfate, sodium alkyl sulfonate, sodium alkyl ether sulfate, monoalkyl phosphate, and sodium polyoxyethylene alkyl ether phosphate. , sodium fatty acid ester sulfonate, sodium fatty acid ester sulfate, sodium fatty acid alkylose amide sulfate, sodium fatty acid amide sulfonate, and the like. Examples of the cationic surfactant include trialkylmethylammonium chloride, alkyltrimethylammonium chloride, dialkyldimethylammonium chloride, alkyldimethylbenzylammonium chloride, and alkylpyridinium chloride. Examples of the zwitterionic surfactant include alkylaminocarboxylate, carboxybetaine, alkylbetaine, sulfobetaine, phosphobetaine, and the like. Examples of nonionic surfactants include sucrose fatty acid ester, polyoxyethylene fatty acid ester, polyoxyethylene lauric fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene glycol monofatty acid ester, polyoxyethylene alkylphenyl ether, and polyoxyethylene sorbitan fatty acid ester. Examples include oxyalkyl ether, fatty acid alkanolamide, fatty acid monoethanolamide, fatty acid diethanolamide, fatty acid triethanolamide, polyoxyethylene fatty acid amide, isopropanolamide, alkylamine oxide, and polyoxyethyleneamine. In addition, the alkyl mentioned here can be exemplified by a linear saturated hydrocarbon group having 2 to 30 carbon atoms, a linear unsaturated hydrocarbon group, a branched saturated hydrocarbon group, or a branched unsaturated hydrocarbon group. . Among these, anionic surfactants, zwitterionic surfactants, and nonionic surfactants are preferred, and anionic surfactants and nonionic surfactants are particularly preferred, particularly polyoxyethylene fatty acid esters, Preferred examples include sodium fatty acid, potassium fatty acid, sodium alkylbenzene sulfonate, sodium alkyl sulfate, sodium alkyl sulfonate, sodium alkyl ether sulfate, sodium fatty acid ester sulfonate, and sodium fatty acid ester sulfate.

The lower limit of the amount of surfactant added is, for example, 0.01 part by weight or more, preferably 0.5 part by weight or more, and more preferably 1 part by weight or more, based on 100 parts by weight of the dispersion medium. The upper limit of the amount added is, for example, 100 parts by weight or less, preferably 20 parts by weight or less, and more preferably 10 parts by weight or less, per 100 parts by weight of the dispersion medium. The amount of polyarylene sulfide copolymer fine particles dispersed in a dispersion medium containing a surfactant is 0.1 parts by weight or more and 50 parts by weight or less of polyarylene sulfide copolymer fine particles per 100 parts by weight of a dispersion medium containing a surfactant. The range of can be exemplified. The polyarylene sulfide copolymer fine particles can be uniformly dispersed in the dispersion medium by adjusting the amount of the surfactant added and the dispersion amount of the polyarylene sulfide copolymer fine particles as described above. In order to more efficiently and uniformly disperse the polyarylene sulfide copolymer fine particles, the dispersion liquid may be heated, irradiated with ultrasonic waves, irradiated with a laser, irradiated with microwaves, or the like.

The dispersion thus obtained is a useful polyarylene sulfide copolymer fine particle dispersion that can be used as an additive for improving heat resistance in the fields of adhesive materials, paints, and polymer compounds. Furthermore, as will be described later, efficient and homogeneous dispersion is possible when blending with inorganic fillers and organic fillers.

[Composition containing polyarylene sulfide copolymer fine particles]
The polyarylene sulfide copolymer fine particles can also be used by blending other optional components such as a crystal nucleating agent, various fillers and/or additives, and these components can be blended to form a resin composition. When producing a resin composition, a more homogeneous resin composition can be efficiently obtained by blending with fine particles.

Examples of crystal nucleating agents include talc, kaolin, organic phosphorus compounds, and polyetheretherketone. Examples of the filler include inorganic fillers and organic fillers. Although the type of filler is not specified, in consideration of the reinforcing effect of the filler as a resin composition, fibrous inorganic fillers such as glass fiber and carbon fiber are preferable. Carbon fiber not only has the effect of improving mechanical properties but also has the effect of reducing the weight of molded products. Further, when the filler is carbon fiber, it is more preferable because the effect of improving the mechanical properties and chemical resistance of the resin composition is greater. When using a fibrous inorganic filler as a filler, it is possible to employ a powder method or a drawing method. The powder method involves dispersing the polyarylene sulfide copolymer into the gaps between the fibers of the reinforcing fiber bundle, then melting the polyarylene sulfide copolymer and applying pressure to impregnate the reinforcing fiber bundle with the polyarylene sulfide copolymer. However, by using polyarylene sulfide copolymer fine particles, it becomes possible to efficiently and more uniformly disperse the polyarylene sulfide copolymer in the gaps between the fibers of the reinforcing fiber bundle. At the time of dispersion, it is possible to directly disperse the polyarylene sulfide copolymer fine particles, or it is also possible to use a dispersion liquid. The drawing method is a method of impregnating the reinforcing fiber bundle with the polyarylene sulfide copolymer by immersing the reinforcing fiber bundle in molten polyarylene sulfide copolymer and applying pressure. By using , it becomes possible to uniformly melt the polyarylene sulfide copolymer in a shorter time, leading to improved productivity and homogeneity.

[Applications of polyarylene sulfide copolymer fine particles]
Polyarylene sulfide copolymer fine particles with excellent chemical resistance, high heat resistance, and a specific median diameter D50 can be used in injection molding, injection compression molding, blow molding, and extrusion molding in the same way as polyarylene sulfide copolymers. In addition, it can be used as a heat-resistant additive in the fields of adhesive materials, paints, and polymer compounds, and as a raw material for three-dimensional modeling using the powder bed fusion bonding method. Three-dimensional objects have excellent chemical resistance, high heat resistance, and excellent mechanical properties derived from the properties of polyarylene sulfide copolymers, and are homogeneous and sufficient due to the fact that they are formed using fine particles. It has high density and excellent surface quality. Further, by blending fillers and/or other additives with the polyarylene sulfide copolymer fine particles, a more homogeneous resin composition can be efficiently obtained. In particular, when blended with a fibrous inorganic filler, the polyarylene sulfide copolymer fine particles are blended more homogeneously, making it possible to obtain a composite base material with excellent mechanical properties and a molded product containing the composite base material. can.

The polyarylene sulfide copolymer fine particles, the three-dimensional structures mentioned above, and the polyarylene sulfide copolymer composition have excellent heat resistance, chemical resistance, flame retardance, electrical properties, and mechanical properties, and are used for electrical - Examples of various uses include electronic parts, audio equipment parts, household and office electrical product parts, machine-related parts, optical equipment, precision machinery-related parts, plumbing parts, automobile and vehicle-related parts, aerospace-related parts, and more.

Hereinafter, the method of the present invention will be explained in more detail with reference to Examples and Comparative Examples, but the present invention is not limited only to these Examples.

[Analysis of functional group content]
The amount of amino groups that polyarylene sulfide (A) has is determined by FT-IR (IR-810 type red manufactured by JASCO Corporation), which was prepared by rapidly cooling polyarylene sulfide from a molten state by heating at 320°C. It was estimated by comparing the absorption intensity at 3382 cm ^-1 derived from the amino group with the absorption intensity at 1901 cm ^-1 derived from the benzene ring of the arylene sulfide unit.

[Molecular weight measurement]
The weight average molecular weight Mw was calculated in terms of polystyrene by gel permeation chromatography (GPC), which is 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°C
Pre constant temperature bath temperature: 250℃
Pump constant temperature bath temperature: 50℃
Detector temperature: 210℃
Flow rate: 1.0mL/min
Sample injection volume: 300 μL.

[Measurement of glass transition point, melting point and crystallization temperature]
The glass transition point (Tg), melting point (Tm), and crystallization temperature (Tmc) were measured using a differential scanning calorimeter (DSC) using about 10 mg of an amorphous film prepared by rapidly cooling from a molten state. The glass transition point was defined as the inflection point of the baseline shift detected when the temperature was raised from 0°C to 340°C at a rate of 20°C/min. The crystallization temperature is the crystallization detected when the temperature is raised from 0°C to 340°C at a rate of 20°C/min, held at 340°C for 1 minute, and then lowered to 100°C at a rate of 20°C/min. The value was taken as the peak temperature. The melting point was determined by increasing the temperature from 0°C to 340°C at a rate of 20°C/min, holding it at 340°C for 1 minute, decreasing the temperature to 100°C at a rate of 20°C/min, and holding it at 100°C for 1 minute. The melting peak temperature detected when the temperature was raised again to 340°C at a rate of 20°C/min was taken as the value.
Equipment: TA Instrument TA-Q200
Carrier gas: Nitrogen Sample purge flow rate: 50 mL/min.

[Particle size and particle size distribution in methanol dispersion]
The median diameter D50 and D90/D10 in the present invention are values measured using a methanol dispersion. A dispersion of about 4 mg of polyarylene sulfide copolymer particles or polyarylene sulfide particles dispersed in about 10 mL of methanol can be measured according to each sample using a Shimadzu powder distribution measuring device (SALD-2100). It was diluted with methanol to a certain concentration and the particle size distribution was measured. D50 is the particle size at which the cumulative frequency from the small particle size side of the particle size distribution is 50%, and D90/D10 is the particle size at which the cumulative frequency from the small particle size side of the particle size distribution is 90% (D90 ) divided by the particle size (D10) at which the cumulative frequency from the small particle size side is 10%.

[Particle size and particle size distribution in aqueous dispersion, volume average perimeter]
Particle size distribution measurements using aqueous dispersions were also carried out. Add approximately 100 mg of polyarylene sulfide copolymer fine particles or polyarylene sulfide fine particles to approximately 5 mL of deionized water in advance and disperse them in a laser diffraction particle size distribution analyzer (Microtrac MT3300EX II) manufactured by Nikkiso Co., Ltd. A dispersion liquid prepared by dropping Triton Particle size distribution was measured. In addition, images of particles in the dispersion flowing through the glass cell were taken, and the volume-average circumference was calculated by analyzing the images of individual particles.

[Sphericity]
The sphericity of polyarylene sulfide copolymer particles or polyarylene sulfide particles was determined by randomly observing 30 particles from photographs taken with a Keyence Digital Microscope (VHX-7000), and determining their major and minor axes. It was calculated according to the following formula. The major axis is the diameter at which the distance between the parallel lines is maximum when the image of the particle is sandwiched between two parallel lines, and the minor axis is the diameter when the particle image is sandwiched between two parallel lines in the direction perpendicular to the major axis diameter. This is the diameter at which the distance between parallel lines is the minimum.

In addition, in the formula, S: sphericity, a: major axis, b: minor axis, and n: number of measurements is 30.

[Loose bulk density]
Polyarylene sulfide copolymer, polyarylene sulfide copolymer fine particles, or polyarylene sulfide fine particles are dropped into a 10 mL or 50 mL glass graduated cylinder using a funnel, the volume is read, and the polyarylene sulfide copolymer, poly The value obtained by dividing the weight of the arylene sulfide copolymer fine particles or polyarylene sulfide fine particles by the volume was defined as the loose bulk density.

[Organic solvent]
The following reagents were used as organic solvents for dissolving the polyarylene sulfide copolymer or polyarylene sulfide.
1-Chloronaphthalene: Manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. For GPC Moisture standard value ≦0.1%
NMP: Manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., for electronic industry, moisture standard value ≦100ppm
Benzophenone: Manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. Wako special grade Moisture standard value ≦0.5%

[Reference example 1]
In an autoclave with a stirrer and a bottom stopper valve, 7.14 kg (61.6 mol) of 48.4% sodium bisulfide, 2.87 kg (69.3 mol) of 97% sodium hydroxide, and N-methyl-2-pyrrolidone. (NMP) 14.57 kg (147 mol) and ion-exchanged water 4.19 kg were charged, and heated gradually to 225°C over about 3 hours while passing nitrogen under normal pressure, distilling 7.88 kg of water and 0.039 kg of NMP. At that point, heating was completed and cooling was started. At this point, the amount of hydrogen sulfide scattered was 1.4 moles, so the amount of inorganic sulfidating agent in the system after this step was 60.2 moles.

Thereafter, it was cooled to 200°C, and p-dichlorobenzene (p-DCB) 9.45 kg (64.3 mol), 4-aminothiophenol (4-ATP) 1.02 kg (8.23 mol), NMP 2.78 kg After adding (28.0 mol), the reaction vessel was sealed under nitrogen gas, and the temperature was raised to 260°C at a rate of 0.6°C/min while stirring, and the reaction was carried out at 260°C for 120 minutes.

Immediately after the completion of the reaction, open the bottom valve of the autoclave, flush the contents into a device with a stirrer, and dry in the device with a stirrer at 230°C for 1.5 hours to recover solids containing PPS and salts. did.

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

3 kg of the obtained PPS and 30 kg of N-methyl-2-pyrrolidone (NMP) were placed in a container equipped with a stirrer, stirred for 30 minutes, and filtered through a filter to obtain a cake. The obtained cake was washed with 30 liters 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 dry PPS. The amount of amino groups was 730 μmol/g, and the number average molecular weight was 1,800.

[Reference example 2]
The PPS obtained in Reference Example 1 and pyromellitic anhydride were heated using a stirrer with a stirring blade so that the ratio of the amount of acid anhydride groups in pyromellitic anhydride/the amount of amino groups in PPS was 1.002. After charging the mixture into a reaction vessel that can be depressurized and replaced with nitrogen, the pressure inside the reaction vessel was reduced and the nitrogen replacement was repeated three times. While the inside of the reaction vessel was filled with nitrogen atmosphere, the temperature was adjusted to 300°C and heated for 3 minutes while stirring.Then, the temperature was further adjusted to 340°C and heated for 3 minutes while stirring, then cooled to room temperature and the PPS copolymer was added. Obtained union.

It was confirmed from the FT-IR spectrum that the obtained PPS copolymer contained a phenylene sulfide unit as a structural unit and that an imide group was introduced. As a result of DSC measurement, the glass transition point was 118°C, the crystallization temperature was 160°C, and the melting point was 253°C. As a result of GPC measurement, Mw was 69,200. The PPS copolymer was in the form of pellets and had a loose bulk density of 0.82 g/mL. The results are summarized in Table 1.

[Reference example 3]
The initial charges were 9.5 kg (81.9 mol) of 48.4% sodium hydrosulfide, 3.84 kg (93.1 mol) of 97% sodium hydroxide, 13.4 kg (135 mol) of NMP, and 9.9 kg (81.9 mol) of ion-exchanged water. 82 kg and heated to 225°C to distill water and NMP, p-DCB 12.6 kg (85.9 mol), 4-ATP 1.07 kg (8.55 mol), NMP 19.8 kg (200 mol) Dried PPS was obtained in the same manner as in Reference Example 1 except that the reaction was carried out by adding . The amount of amino groups was 510 μmol/g, and the number average molecular weight was 3,200.

[Reference example 4]
PPS obtained in Reference Example 3 and pyromellitic anhydride were dry blended so that the ratio of the amount of acid anhydride groups in pyromellitic anhydride/the amount of amino groups in PPS was 1.200, Using a TEX30α twin-screw extruder (L/D ~ 45, 3 kneading parts) manufactured by Japan Steel Works, Ltd. equipped with a vacuum vent, the PPS copolymer was melt-kneaded at a cylinder temperature of 300°C and a screw rotation speed of 200 rpm. I got it.

It was confirmed from the FT-IR spectrum that the obtained PPS copolymer contained a phenylene sulfide unit as a structural unit and that an imide group was introduced. As a result of DSC measurement, the glass transition point was 114°C, the crystallization temperature was 171°C, and the melting point was 263°C. As a result of GPC measurement, Mw was 46,700. The PPS copolymer was in the form of pellets and had a loose bulk density of 0.83 g/mL. The results are summarized in Table 1.

[Example 1]
0.3 g of the PPS copolymer obtained in Reference Example 2 and 5.4 g (4.5 mL) of 1-chloronaphthalene were placed in a 20 mL pressure-resistant container, and the container was purged with nitrogen and then sealed. After heating at 250° C. for 20 minutes while stirring at 240 rpm, the container was allowed to cool. After cooling to around room temperature over about 30 minutes while maintaining stirring, the mixed solution was taken out from the pressure container, 20 mL of methanol was added, stirred, and then filtered. The solvent was removed by stirring and filtration in methanol and then stirring and filtration in water, followed by vacuum drying at 100°C to obtain polyarylene sulfide copolymer fine particles. The glass transition point was 117°C, the crystallization temperature was 177°C, and the melting point was 252°C. The Mw was 59,600, and the Mw retention rate of the PPS copolymer fine particles with respect to the Mw of the PPS copolymer of Reference Example 2 was 86%. D50 in methanol dispersion is 31.6 μm, D90/D10 is 5.1, D50 in aqueous dispersion is 30.1 μm, D90/D10 is 3.8, volume average perimeter is 144 μm (measured count number 1217). The sphericity was 72%. The results are summarized in Table 1.

[Example 2]
Polyarylene sulfide copolymer fine particles were obtained under the same conditions as in Example 1 except that 1-chloronaphthalene to which 1 wt% of water was added was used. The glass transition point was 116°C, the crystallization temperature was 183°C, and the melting point was 253°C. The Mw was 47,300, and the Mw retention rate of the PPS copolymer fine particles with respect to the Mw of the PPS copolymer of Reference Example 2 was 68%. D50 in the methanol dispersion was 14.6 μm, and D90/D10 was 5.1. The results are summarized in Table 1.

[Example 3]
50 g of the PPS copolymer obtained in Reference Example 2 and 750 g of NMP were placed in a 1 L pressure-resistant container, and after the inside of the container was purged with nitrogen, the container was sealed. The temperature was raised to 250°C at 2°C/min while stirring at 240 rpm, and after heating at 250°C for 15 minutes, the mixture was cooled at 6°C/min while stirring. After cooling to around room temperature, the mixed solution was taken out from the pressure container and filtered. After adding 750 g of water and stirring, the mixture was filtered, the solvent was removed, and the mixture was vacuum dried at 130° C. to obtain polyarylene sulfide copolymer fine particles. The glass transition point was 115°C, the crystallization temperature was 195°C, and the melting point was 257°C. The Mw was 39,200, and the Mw retention rate of the PPS copolymer fine particles with respect to the Mw of the PPS copolymer of Reference Example 2 was 57%. D50 in methanol dispersion is 53.6 μm, D90/D10 is 4.3, D50 in aqueous dispersion is 52.8 μm, D90/D10 is 2.9, volume average circumference is 215 μm (measured count number). 736). The loose bulk density was 0.40 g/mL. The sphericity was 70%. The results are summarized in Table 1.

[Example 4]
5 g of the PPS copolymer obtained in Reference Example 4 and 50 g of benzophenone were placed in a 100 mL glass container, and heated to 250°C by stirring at 200 rpm while flowing a nitrogen stream into the container at a rate of 100 mL/min. After confirming that the entire amount of polymer had dissolved, the container was allowed to cool. While stirring, the mixture was cooled to 100° C. over about 15 minutes, and the mixed solution was taken out from the container and filtered while hot. Thereafter, the solvent was removed by stirring and filtration in acetone, followed by vacuum drying at room temperature to obtain polyarylene sulfide copolymer fine particles. The glass transition point was 113°C, the crystallization temperature was 196°C, and the melting point was 260°C. The Mw was 46,100, and the Mw retention rate of the PPS copolymer fine particles with respect to the Mw of the PPS copolymer of Reference Example 3 was 99%. D50 in the methanol dispersion was 48 μm, and D90/D10 was 7.6. The results are summarized in Table 1.

[Comparative example 1]
1.5 g of the PPS copolymer obtained in Reference Example 2 was freeze-pulverized in liquid nitrogen for 23 minutes. D50 in the methanol dispersion was 198 μm, and D90/D10 was 12.7. The sphericity was 64%.

[Comparative example 2]
In a 20 mL pressure-resistant container, 0.3 g of the PPS copolymer obtained in Reference Example 2 and 4.5 g of NMP to which 1000 ppm of water had been added were placed, and the inside of the container was replaced with nitrogen and then sealed. After heating at 250° C. for 20 minutes while stirring at 240 rpm, the container was allowed to cool. After cooling to around room temperature over about 30 minutes while maintaining stirring, the mixed solution was taken out from the pressure container, 20 mL of water was added, stirred, and then filtered. After repeating stirring in water and filtration to remove the solvent, vacuum drying was performed at 100°C to obtain polyarylene sulfide copolymer fine particles. The glass transition point was 110°C, the crystallization temperature was 214°C, and the melting point was 261°C. The Mw was 25,300, and the Mw retention rate of the PPS copolymer fine particles with respect to the Mw of the PPS copolymer of Reference Example 2 was 37%. D50 in the methanol dispersion was 15.9 μm, and D90/D10 was 5.5. The sphericity was 76%. The results are summarized in Table 1.

[Reference example 5]
In a 70-liter autoclave equipped with a stirrer, 8.27 kg (70.00 mol) of 47.5% sodium hydrogen sulfide, 2.96 kg (70.97 mol) of 96% sodium hydroxide, and N-methyl-2-pyrrolidone (NMP) were added. ) 11.43 kg (115.50 mol), 2.58 kg (31.50 mol) of sodium acetate, and 10.5 kg of ion-exchanged water, and gradually heated to 245°C over about 3 hours while passing nitrogen under normal pressure. After distilling off 14.78 kg of water and 0.28 kg of NMP, the reaction vessel was cooled to 160°C. The amount of water remaining in the system per mole of alkali metal sulfide charged was 1.06 moles, including the water consumed for hydrolysis of NMP. Further, the amount of hydrogen sulfide scattered was 0.02 mol per mol of the alkali metal sulfide charged.

Next, 10.24 kg (69.63 mol) of p-dichlorobenzene and 9.01 kg (91.00 mol) of NMP were added, the reaction vessel was sealed under nitrogen gas, and the mixture was stirred at a rate of 0.6°C/min. The temperature was raised to 238°C. After reacting at 238°C for 95 minutes, the temperature was raised to 270°C at a rate of 0.8°C/min. After carrying out the reaction at 270°C for 100 minutes, it was cooled to 250°C at a rate of 1.3°C/min while 1.26 kg (70 mol) of water was introduced under pressure over 15 minutes. Thereafter, it was cooled to 200° C. at a rate of 1.0° C./min, and then rapidly cooled to near room temperature.

The contents were taken out and diluted with 26.30 kg of NMP, and then the solvent and solid matter were filtered off using a sieve (80 mesh), and the resulting particles were washed and filtered with 31.90 kg of NMP. This was washed several times with 56.00 kg of ion-exchanged water and filtered, and then washed with 70.00 kg of 0.05% by weight acetic acid aqueous solution and filtered. After washing with 70.00 kg of ion-exchanged water and filtering, the obtained water-containing PPS particles were dried with hot air at 80°C and then dried under reduced pressure at 120°C. The glass transition point was 94°C, the crystallization temperature was 219°C, and the melting point was 278°C. Mw was 75,100.

[Reference example 6]
PPS fine particles were obtained under the same conditions as in Example 3, except that the PPS obtained in Reference Example 5 was used instead of the PPS copolymer obtained in Reference Example 2. The glass transition point was 94°C, the crystallization temperature was 220°C, and the melting point was 278°C. The Mw was 73,300, and the Mw retention rate of the PPS fine particles with respect to the Mw of PPS of Reference Example 3 was 98%. D50 in methanol dispersion is 55.2 μm, D90/D10 is 2.0, D50 in aqueous dispersion is 57.4 μm, D90/D10 is 2.6, volume average perimeter is 255 μm (measured count number 791). The loose bulk density was 0.08 g/mL. The sphericity was 73%. The results are summarized in Table 1.

As shown in Examples 1 to 4, the present invention uses a polyarylene sulfide having a glass transition point of 95°C or higher, a weight average molecular weight Mw of 30,000 or more, and a D50 particle size of 10 μm or more and 150 μm or less. Copolymer fine particles can be obtained.

As shown in Comparative Example 1, when the pellet-shaped PPS copolymer was freeze-pulverized, both the D50 particle size and D90/D10 were larger than the PPS copolymer fine particles obtained in Examples 1 to 4, and the true The sphericity was also small, and micronization was insufficient.

As shown in Reference Example 5 and Reference Example 6, when PPS is dissolved in NMP and precipitated, Mw does not decrease, but as shown in Example 3 and Comparative Example 2, when PPS copolymer is dissolved in NMP and precipitated, Mw does not decrease. In the case of precipitation, Mw decreased. Furthermore, as shown in Examples 1 and 2, the Mw also decreased when the PPS copolymer was dissolved in 1-chloronaphthalene and precipitated. As described above, it has been difficult to directly apply the conventionally known method of dissolving PPS in a solvent and precipitating it to PPS copolymers.

A comparison of Example 3 and Comparative Example 2 and a comparison of Examples 1 and 2 shows that the water content in NMP affects the reduction in Mw, and that the reduction in Mw can be suppressed by using a solvent with a low water content. . In addition, from a comparison of Examples 1 and 2 in which 1-chloronaphthalene was used as a solvent, Example 4 in which benzophenone was used as a solvent, and Example 3 and Comparative Example 2 in which NMP was used as a solvent, it was found that polar solvents were It can be seen that PPS copolymer fine particles having a relatively higher Mw can be obtained when a hydrophobic solvent is used than when using a hydrophobic solvent.

From a comparison of Example 1, Example 3, and Reference Example 6, it was found that the PPS copolymer fine particles obtained by dissolving and precipitating a PPS copolymer were better than the PPS fine particles obtained by dissolving and precipitating PPS. However, it can be seen that fine particles with a small volume average circumference can be obtained. From the comparison between Example 3 and Reference Example 6, it is found that the PPS copolymer fine particles obtained by dissolving and precipitating a PPS copolymer have a higher bulk density than the PPS fine particles obtained by dissolving and precipitating PPS. It can be seen that fine particles with a large size can be obtained. It is speculated that this is due to differences in solubility or crystallinity.

Claims (16)

A polyarylene sulfide having a glass transition point measured by differential scanning calorimetry of 95° C. or more and 190° C. or less, a weight average molecular weight Mw of 30,000 or more, and a median diameter D50 of 10 μm or more and 150 μm or less. Polymer fine particles. The polyarylene sulfide copolymer according to claim 1, containing at least one bonding group selected from a sulfonyl group, a sulfinyl group, an ester group, an amide group, an imide group, an ether group, a urea group, a urethane group, and a siloxane group. Fine particles. The polyarylene sulfide copolymer fine particles according to claim 1, having a structure in which the arylene sulfide unit and the copolymerization component are connected through an imide group. The polyarylene sulfide copolymer fine particles according to claim 1, having as a structural unit at least one structure selected from the following formulas (a) to (s).

(R, R ¹ and R ² are substituents 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; ² may be the same or different.) The polyarylene sulfide copolymer fine particles according to claim 1, which have an arylene sulfide unit having a number average molecular weight Mn of 1,000 or more and 10,000 or less as a structural unit. A dispersion liquid in which the polyarylene sulfide copolymer fine particles according to any one of claims 1 to 5 are dispersed in water containing a surfactant. The polyarylene sulfide according to claim 1, comprising the steps of dissolving a polyarylene sulfide copolymer having a glass transition point of 95° C. or higher and 190° C. or lower as determined by differential scanning calorimetry in a solvent, precipitating the polyarylene sulfide copolymer, and removing the solvent. Method for producing copolymer fine particles. The method for producing polyarylene sulfide copolymer fine particles according to claim 7, wherein the polyarylene sulfide copolymer is dissolved in a hydrophobic solvent. The method for producing polyarylene sulfide copolymer fine particles according to claim 7, wherein the polyarylene sulfide copolymer is dissolved in a polar solvent. The method for producing polyarylene sulfide copolymer fine particles according to claim 7, wherein the polyarylene sulfide copolymer is dissolved in an aprotic polar solvent. 8. The method for producing polyarylene sulfide copolymer fine particles according to claim 7, wherein the water content of the solvent in which the polyarylene sulfide copolymer is dissolved is 1000 ppm or less. 8. The method for producing polyarylene sulfide copolymer fine particles according to claim 7, wherein the polyarylene sulfide copolymer is dissolved in a solvent under normal pressure. The method for producing polyarylene sulfide copolymer fine particles according to any one of claims 7 to 12, wherein the polyarylene sulfide copolymer has a loose bulk density of 0.5 g/mL or more. The polyarylene sulfide copolymer has a number average molecular weight Mn of 1,000 to 10,000, and has two carboxyl groups bonded to two adjacent carbons, or an acid anhydride derived from the two carboxyl groups. at least one selected from the group consisting of amino groups, hydroxyl groups, carboxyl groups, silanol groups, sulfonic acid groups, acetamido groups, sulfonamide groups, cyano groups, isocyanate groups, aldehyde groups, acetyl groups, epoxy groups, and alkoxysilyl groups. Claimed to be a polyarylene sulfide copolymer obtained by heating polyarylene sulfide (A) having two functional groups and at least one compound (B) selected from the following formulas (a') to (u'). Item 13. The method for producing polyarylene sulfide copolymer fine particles according to any one of Items 7 to 12.

(X is two carboxyl groups each bonded to two adjacent carbons, or an acid anhydride group derived from the two carboxyl groups, an amino group, a hydroxyl group, a carboxyl group, a silanol group, a sulfonic acid group, an acetamide group, At least one selected from a sulfonamide group, a cyano group, an isocyanate group, an aldehyde group, an acetyl group, an epoxy group, and an alkoxysilyl group, and R, R ¹ and R ² are hydrogen and have 1 to 12 carbon atoms. is a substituent selected from an alkyl group, an arylene group having 6 to 24 carbon atoms, and a halogen group, and R, R ¹ , and R ² may be the same or different. Also, the aromatic ring of each compound may be a di- or tri-substituted product, and the multiple substituents X substituted on one aromatic ring may be the same or different.) The polyarylene sulfide copolymer has a number average molecular weight Mn of 1,000 to 10,000, and has two carboxyl groups bonded to two adjacent carbons, or an acid anhydride derived from the two carboxyl groups. polyarylene sulfide (A) having at least one functional group selected from a group and an amino group, and the substituent X is derived from two carboxyl groups each bonded to two adjacent carbons or the two carboxyl groups The polyarylene sulfide copolymer according to any one of claims 7 to 12, which is a polyarylene sulfide copolymer obtained by heating the compound (B) which is at least one selected from an acid anhydride group and an amino group. Method for producing polymer fine particles. Any one of claims 7 to 12, wherein the polyarylene sulfide copolymer is a polyarylene sulfide copolymer obtained by heating polyarylene sulfide (A) and compound (B) under substantially solvent-free conditions. The method for producing the polyarylene sulfide copolymer fine particles described above.