Polyarylene sulfide copolymer and method for producing the same, and fiber-reinforced polyarylene sulfide copolymer composite base material

Abstract

To provide a polyarylene sulfide copolymer which is excellent in rigidity at high temperature and stability of viscosity in heating, and has a small amount of gas to be generated.SOLUTION: A polyarylene sulfide copolymer has a glass transition temperature of 95°C or higher and 190°C or lower, contains an antioxidant, and has a viscosity change rate Δη represented by the following expression (1) of more than 1 time and 10 times or less, and a weight reduction rate ΔW represented by the following expression (2) of 0.5% or less. Expression (1): Δη=η2 / η1. In the expression (1), η1 is melting complex viscosity measured at 340°C and angular frequency of 6.28 rad / s and shear stress of 1,000 Pa under non-oxidation atmosphere at normal temperature, before heating treatment, and η2 is melting complex viscosity measured after heating treatment at 340°C for 20 minutes under non-oxidation atmosphere at normal temperature. Expression (2): ΔW=(W1-W2) / W1×100. In the expression (2), W1 is a sample weight at the time of arrival at 100°C when the temperature is raised from 30°C to 320°C at a temperature raising rate of 10°C / min under non-oxidation atmosphere at normal temperature, and W2 is a sample weight after keeping the temperature for 60 minutes after arriving at 320°C.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a polyarylene sulfide copolymer, a method for producing the same, and a fiber-reinforced polyarylene sulfide copolymer composite substrate.

Background Art

[0002] Polyarylene sulfide (hereinafter sometimes abbreviated as PAS), typified by polyphenylene sulfide (hereinafter sometimes abbreviated as PPS), has properties suitable as an engineering plastic such as excellent heat resistance, barrier properties, moldability, chemical resistance, electrical insulation properties, and heat and humidity resistance. It is used in various electrical and electronic parts, mechanical parts, automotive parts, films, fibers, etc., mainly for injection molding and extrusion molding applications. Due to its excellent properties, the applications of polyarylene sulfide have been expanding in recent years.

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

[0004] The above-described PPS, which is a representative example of polyarylene sulfide, can withstand use at high temperatures due to its high melting point, but has a problem that its rigidity rapidly decreases at a temperature of 80 to 90 °C or higher, which is the glass transition point, compared to lower temperatures. Various studies have been conducted to improve the glass transition point of polyarylene sulfide.

[0005] For example, Patent Documents 1 to 3 disclose a polyarylene sulfide copolymer obtained by reacting a polyarylene sulfide having a reactive functional group with a rigid molecule.

[0006] In addition, Patent Document 4 discloses a fiber-reinforced polyarylene sulfide copolymer composite substrate in which a polyarylene sulfide copolymer obtained by reacting a polyarylene sulfide having a reactive functional group with a rigid molecule is impregnated into a reinforcing fiber substrate.

[0007] Patent Document 5 discloses a crystalline polyimide containing a cumulative phenylene sulfide unit having an improved glass transition temperature by bonding a 2- to 9-mer phenylene sulfide and an arylene group with an imide bond.

[0008] Patent Document 6 discloses a copolymer composed of a polyarylene sulfide block and a polyetherimide block or a polydiorganosiloxane block.

[0009] While studies have been conducted to improve the glass transition temperature of polyarylene sulfide, thermoplastic resins typified by polyarylene sulfide have a problem that the melt viscosity tends to change during melt residence. For example, in polyarylene sulfide-based resins, there is a problem that the melt viscosity tends to significantly increase during melt residence in the presence of oxygen, the melt molding processability deteriorates due to a decrease in fluidity, and the crystallinity and mechanical properties deteriorate due to side reactions including oxidative crosslinking. In response to such problems, studies have been conducted to contain a stabilizer to improve the thermal stability.

[0010] For example, Patent Document 7 discloses a polyarylene sulfide resin composition having improved thermal stability by containing a transition metal compound or a transition metal compound and an amine compound.

[0011] Patent Document 8 discloses a polyarylene sulfide resin composition having a small viscosity change during melt residence and improved thermal stability by containing an organic nickel compound.

[0012] Patent Document 9 discloses a thermoplastic resin composition having improved thermal stability by containing nanodiamond particles, which suppresses deterioration and thickening during heat processing.

Prior Art Documents

Patent Documents

[0013]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Patent Document 6

Patent Document 7

Patent Document 8

Patent Document 9

Summary of the Invention

Problems to be Solved by the Invention

[0014] However, although the polyarylene sulfide copolymer disclosed in Patent Documents 1 to 3 has a high glass transition point, the melt viscosity increases during melt residence, so a polyarylene sulfide copolymer with a small viscosity increase rate has been desired.

[0015] In addition, although the fiber-reinforced polyarylene sulfide copolymer composite substrate disclosed in Patent Document 4 has a high glass transition temperature, the polyarylene sulfide copolymer to be impregnated has an increased melt viscosity during melt residence. Therefore, a polyarylene sulfide copolymer with a small viscosity increase rate during melt residence has been desired. Patent Document 4 discloses that the molecular weight of the polyarylene sulfide copolymer impregnated in the fiber-reinforced polyarylene sulfide copolymer composite substrate is substantially the same as the molecular weight of the polyarylene sulfide copolymer before being used as a substrate. However, since the viscosity increases under the melt residence conditions at a high temperature in the atmosphere, a small viscosity increase rate is required, and more excellent thermal stability has been desired.

[0016] Patent Documents 1 and 4 disclose that an antioxidant can be blended for the purpose of modification. However, simply blending an antioxidant has a different problem that the amount of gas generated during melting increases.

[0017] Although the crystalline polyimide disclosed in Patent Document 5 has an improved glass transition temperature, due to the small molecular weight of the phenylene sulfide unit, it tends to contain a large amount of low molecular weight volatile components and has a relatively high melt viscosity. Although there is no description regarding the viscosity change during melt residence, since it contains a chemical structure similar to the polyarylene sulfide copolymer disclosed in Patent Documents 1 to 4, it has the same problem of viscosity increase and has the problem that the viscosity further increases from the relatively high melt viscosity.

[0018] Regarding the copolymer disclosed in Patent Document 6, although the glass transition temperature is improved, since it has a polyetherimide block or a polydiorganosiloxane block as a block structure, the melt viscosity tends to be relatively high. Although there is no description regarding the viscosity change during melt residence, since it contains a chemical structure similar to the polyarylene sulfide copolymer disclosed in Patent Documents 1 to 4, it has the same problem of viscosity increase and has the problem that the relatively high melt viscosity further increases. Furthermore, since the copolymer is produced in the presence of an organic solvent, it also has the problem that the amount of gas generated tends to increase.

[0019] The polyarylene sulfide resin composition disclosed in Patent Document 7 uses a transition metal compound or a transition metal compound and an amine compound. Although these compounds have the effect of improving thermal stability, there has been a problem that the mechanical properties deteriorate due to the inclusion of transition metal particles in the resin composition. Further, the increase in the melt viscosity during heating is still large, and a method for further improving thermal stability has been demanded. Furthermore, it has been shown that by reacting an amine compound with a carboxyl group to modify the carboxyl group and coordinating a transition metal compound to an electron-donating group of polyarylene sulfide, the generation of peroxide radicals can be suppressed and a polyarylene sulfide resin composition excellent in thermal stability can be obtained. However, the effect is shown for general polyarylene sulfide and not for polyarylene sulfide copolymer. The polyarylene sulfide copolymer of the present invention contains a structure different from that of general polyarylene sulfide, and it is presumed that a crosslinked structure and an increase in molecular weight due to side reactions with a mechanism different from that of general polyarylene sulfide have occurred.

[0020] In the polyarylene sulfide resin composition disclosed in Patent Document 8, since an organic nickel compound is used, there has been a problem that the mechanical properties deteriorate due to the inclusion of nickel metal particles in the resin composition. Further, the effect of obtaining a polyarylene sulfide having a small viscosity change during melt residence and a small amount of gas generation during heating, which is disclosed in Patent Document 8, is shown for general polyarylene sulfide and not for polyarylene sulfide copolymer. The polyarylene sulfide copolymer of the present invention contains a structure different from that of general polyarylene sulfide, and it is presumed that a crosslinked structure and an increase in molecular weight due to side reactions with a mechanism different from that of general polyarylene sulfide have occurred.

[0021] Even in the thermoplastic resin composition disclosed in Patent Document 9, since nanodiamond particles, which are inorganic compounds, are used, there has been a problem that the mechanical properties deteriorate due to the inclusion of the nanodiamond particles in the resin composition. Further, the effect that a resin composition capable of realizing high heat resistance while suppressing deterioration and thickening during heat processing is obtained as disclosed in Patent Document 9 shows an effect on general polyarylene sulfide and does not show an effect on a polyarylene sulfide copolymer. The polyarylene sulfide copolymer of the present invention contains a structure different from that of general polyarylene sulfide, and it is presumed that a crosslinked structure and a molecular weight increase due to side reactions of a mechanism different from that of general polyarylene sulfide have occurred.

[0022] An object of the present invention is to obtain a polyarylene sulfide copolymer excellent in rigidity at high temperature, excellent in viscosity stability during heating, and having a small amount of generated gas.

Means for Solving the Problems

[0023] The present invention has been made to solve at least a part of the above-described problems, and can be realized by providing the following content. 1. A polyarylene sulfide copolymer having a glass transition point of 95°C or higher and 190°C or lower, containing an antioxidant, having a viscosity change rate Δη represented by the following formula (1) exceeding 1 time and being 10 times or less, and a weight loss rate ΔW represented by the following formula (2) of 0.5% or less. Δη = η2 / η1 ··· (1) (Here, Δη is the viscosity change rate (times), η1 is the melt complex viscosity measured at 340°C, angular frequency 6.28 rad / s, shear stress 1,000 Pa, and normal pressure in a non-oxidizing atmosphere before heat treatment, and η2 is the melt complex viscosity measured at 340°C, angular frequency 6.28 rad / s, shear stress 1,000 Pa, and normal pressure in the atmosphere after heat treatment at 340°C for 20 minutes in the atmosphere at normal pressure.) ΔW = (W1 - W2) / W1 × 100 ··· (2) (Here, ΔW is the weight loss rate (%), W1 is the sample weight at the time of reaching 100°C when the temperature is raised from 30°C to 320°C at a rate of 10°C / min in a non-oxidizing atmosphere at normal pressure, and W2 is the sample weight after isothermal holding at 320°C for 60 minutes.) 2. The polyarylene sulfide copolymer according to 1 above, wherein the melt complex viscosity η3 measured at 340°C, an angular frequency of 6.28 rad / s, and a shear stress of 1,000 Pa after heat treatment at 340°C for 60 minutes in the atmosphere at normal pressure is 10,000 Pa·s or less. 3. The polyarylene sulfide copolymer according to 1 or 2 above, wherein the polyarylene sulfide copolymer has an arylene sulfide unit with a number average molecular weight Mn of 1,000 or more and 10,000 or less. 4. The polyarylene sulfide copolymer according to any one of 1 to 3 above, wherein the polyarylene sulfide copolymer has at least one structure selected from the following formulas (a) to (s) as a structural unit.

[0024]

Chemical formula

[0025] (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, and R, R 1 , and R 2 may be the same or different.) 5. The polyarylene sulfide copolymer according to any one of 1 to 4 above, having a melting point of 300°C or less. 6. The polyarylene sulfide copolymer according to any one of 1 to 5 above, having a weight average molecular weight Mw of 10,000 or more and 200,000 or less. 7. The polyarylene sulfide copolymer according to any one of 1 to 6 above, having a dispersity represented by weight average molecular weight Mw / number average molecular weight Mn of 7.0 or less. 8. A fiber-reinforced polyarylene sulfide copolymer composite substrate obtained by impregnating a continuous reinforcing fiber or a reinforcing fiber substrate in which discontinuous reinforcing fibers are dispersed with the polyarylene sulfide copolymer according to any one of 1 to 7 above. 9. A method for producing a polyarylene sulfide copolymer, comprising at least performing step 1, in which a polyarylene sulfide (A) (hereinafter sometimes abbreviated as polyarylene sulfide (A)) containing an amino group in the range of 400 μmol / g or more and 5,000 μmol / g or less and having a weight loss rate of 5 wt% or less when heated at a temperature rising rate of 10 °C / min from 30 °C to 320 °C, and at least one compound (B) (hereinafter sometimes abbreviated as compound (B)) selected from the following formulas (a') to (u') are heated in the presence of an antioxidant. Step 1: A step of melt-extruding polyarylene sulfide (A), compound (B), and an antioxidant using an extruder having a main hopper, and having a first kneading zone, a vent zone, and a second kneading zone configured in this order downstream from the main hopper, wherein the vent zone is provided at a position within 0.5L from the upstream end of the screw. (Here, L is the length of the screw of the extruder.)

[0026]

Chemical formula

[0027] (X is two carboxyl groups each bonded to two adjacent carbons or an acid anhydride group derived from the two carboxyl groups, and 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, and R, R 1 , and R 2 may be the same or different. Also, the aromatic ring of each compound may be a disubstituted or trisubstituted body, and the plurality of substituents X substituted on one aromatic ring may be the same or different.) 10. The method for producing a polyarylene sulfide copolymer according to item 9 above, wherein the vent zone in step 1 is an atmospheric vent zone. 11. The method for producing a polyarylene sulfide copolymer according to item 9 or 10 above, wherein the heating temperature in step 1 is 320 °C or lower. 12. The method for producing a polyarylene sulfide copolymer according to any one of items 9 to 11 above, wherein after step 1, step 2 is performed in which the melt extrudate obtained in step 1 is further melt extruded using an extruder having a vacuum vent. 13. The method for producing a polyarylene sulfide copolymer according to item 12 above, wherein the heating temperature in step 2 exceeds the heating temperature in step 1 and is 370 °C or lower.

Advantages of the Invention

[0028] The present invention can provide a polyarylene sulfide copolymer that is excellent in rigidity at high temperatures, excellent in viscosity stability during heating, and has a small amount of generated gas, and a method for producing the same. Such a polyarylene sulfide copolymer is excellent in heat resistance and melt molding processability, and it is difficult for equipment contamination and voids in molded products to occur during molding, and molded products having excellent mechanical properties can be stably obtained with high productivity.

Embodiments for Carrying Out the Invention

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

[0030] [Polyarylene Sulfide Copolymer] The lower limit of the glass transition point of the polyarylene sulfide copolymer of the present invention is 95 °C or higher. 100 °C or higher is preferable, and 110 °C or higher is more preferable. If the glass transition point is less than 95 °C, high rigidity cannot be obtained under high temperature conditions. Further, the upper limit of the glass transition point is 190 °C or lower. 180 °C or lower is preferable, and 160 °C or lower is more preferable. If the glass transition point exceeds 190 °C, the chemical resistance of the molded product is 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.

[0031] The polyarylene sulfide copolymer of the present invention contains an antioxidant. Examples of the antioxidant include phenolic antioxidants as typical primary antioxidants, phosphorus-based antioxidants and sulfur-based antioxidants as typical secondary antioxidants. Generally, the primary antioxidant rapidly reacts with the radicals of the polymer generated by heat during melt processing to stabilize it, and the secondary antioxidant stabilizes by non-radically decomposing peroxides. The phenolic antioxidant also plays a role in maintaining long-term thermal stability. The phosphorus-based antioxidant enhances the processing stability during melting. Combining a phenolic antioxidant with a phosphorus-based antioxidant or a sulfur-based antioxidant may prevent thermal oxidative degradation or improve long-term thermal stability. The antioxidant may be used alone or in combination of a plurality of antioxidants for the antioxidant effect by a plurality of mechanisms. When used in high-temperature melt processing, a phenolic antioxidant or a phosphorus-based antioxidant with high heat resistance is preferable, and a combination of a phenolic antioxidant and a phosphorus-based antioxidant is more preferable.

[0032] The lower limit of the content of the antioxidant is preferably 0.01 part by weight or more, more preferably 0.05 part by weight or more, still more preferably 0.1 part by weight or more, even more preferably 0.3 part by weight or more, and still even more preferably 0.5 part by weight or more with respect to 100 parts by weight of the polyarylene sulfide copolymer. Further, the polyarylene sulfide copolymer has a copolymer component, different from general polyarylene sulfide. Although details will be described later, for example, it may contain the structures represented by the above formulas (a) to (s) and may contain an amino group derived from polyarylene sulfide (A), a carboxyl group or an acid anhydride group derived from compound (B). Therefore, it is presumed that the polyarylene sulfide copolymer of the present invention forms a crosslinked structure or has a higher molecular weight due to side reactions with different mechanisms compared to general polyarylene sulfide. Therefore, a larger content of the antioxidant in the present invention is more effective compared to the content in general polyarylene sulfide, and 0.3 part by weight or more is effective, 0.4 part by weight or more is more effective, and 0.5 part by weight or more is particularly effective with respect to 100 parts by weight of the polyarylene sulfide copolymer.

[0033] From the viewpoint of suppressing the amount of generated gas caused by the antioxidant and suppressing the deterioration of mechanical properties caused by containing the antioxidant, the upper limit of the content of the antioxidant is preferably 10 parts by weight or less, more preferably 5 parts by weight or less, and still more preferably 3 parts by weight or less with respect to 100 parts by weight of the polyarylene sulfide copolymer.

[0034] Examples of the phenolic antioxidant may be those having a phenolic hydroxy group and having an antioxidant effect. For example, as commercially available products, Irganox1010, Irganox1035, Irganox1076, Irganox1098, Irganox1135, Irganox1141, Irganox1330, Irganox1425WL, Irganox1520L, Irganox245, Irganox259, Irganox3114, Irganox565 manufactured by BASF, and AdekaStab (registered trademark) AO-20, AO-30, AO-40, AO-50, AO-60, AO-80, AO-330 manufactured by ADEKA can be exemplified. In the production of the polyarylene sulfide copolymer, the melt molding process of the polyarylene sulfide copolymer, etc., it can be heated in an environment at a higher temperature than ordinary polyarylene sulfide. Therefore, in addition to the relatively excellent effects of the phenolic antioxidant on the processing stability and long-term thermal stability with respect to the polyarylene sulfide copolymer, heat resistance and volatility resistance are particularly important. From this viewpoint, Irganox1010, Irganox1098, Irganox245, Irganox259, AO-60, AO-80, AO-330 are preferred, and AO-80 is more preferred.

[0035] Examples of phosphorus-based antioxidants include those having a phosphorus atom and having an antioxidant effect. For example, as commercially available products, Irgafos 168 manufactured by BASF, Adeka Stab PEP-8, PEP-36, HP-10, 2112, 1178, 1500, C, 135A, 3010, TPP, etc. manufactured by ADEKA can be exemplified. Similarly for phosphorus-based antioxidants, in addition to having a relatively excellent effect on the processing stability of polyarylene sulfide, particularly heat resistance and volatility resistance are important. From this perspective, Irgafos 168, PEP-8, PEP-36, HP-10, 2112 are preferred, and PEP-36 is more preferred.

[0036] Examples of sulfur-based antioxidants include those having a sulfur atom and having an antioxidant effect. For example, as commercially available products, Irganox PS 800 FL, Irganox PS 802 FL manufactured by BASF, Adeka Stab AO-412S, AO-503, AO-26, etc. manufactured by ADEKA can be exemplified. Similarly for sulfur-based antioxidants, from the perspective of excellent volatility resistance of sulfur-based antioxidants, AO-412S is preferred.

[0037] The antioxidant is preferably incorporated into the polyarylene sulfide copolymer by heating in the presence of the antioxidant at least when heating the polyarylene sulfide (A) and the compound (B) described below to obtain the polyarylene sulfide copolymer. It is also possible to further add an antioxidant to the polyarylene sulfide copolymer obtained by heating the polyarylene sulfide (A), the compound (B), and the antioxidant, for example, by melt kneading or solvent dispersion.

[0038] The polyarylene sulfide copolymer has a viscosity change rate Δη represented by the following formula (1) that exceeds 1 time and is 10 times or less. Δη = η2 / η1 ··· (1) (Here, Δη is the viscosity change rate (times), η1 is the complex melt viscosity measured at 340°C, angular frequency 6.28 rad / s, shear stress 1,000 Pa, and normal pressure in a non-oxidizing atmosphere before heat treatment, and η2 is the complex melt viscosity measured at 340°C, angular frequency 6.28 rad / s, shear stress 1,000 Pa, and normal pressure in the atmosphere after heat treatment at 340°C for 20 minutes under normal pressure.)

[0039] The upper limit of Δη is 10 times or less, preferably 9 times or less, more preferably 7 times or less, still more preferably 5 times or less, even more preferably 3 times or less, and even more preferably 2 times or less. When Δη exceeds 10 times, the melt molding processability deteriorates, and a decrease in properties presumably due to the oxidative crosslinking reaction and a decrease in quality stability occur. From the viewpoint of melt molding processability and the quality stability of the polyarylene sulfide copolymer after melt molding, it is desirable that the complex melt viscosity does not change before and after heat treatment. Therefore, the lower limit of Δη is desirably 1 time, but in the polyarylene sulfide copolymer of the present invention, even a general polyarylene sulfide may have a viscosity change, and different viscosity change mechanisms may occur because it contains a structure different from that of a general polyarylene sulfide, so it exceeds 1 time.

[0040] There is no particular limitation on the method of heat treatment for obtaining Δη, but examples include a method of adding a sample to a test tube, setting the inside of the system to the atmosphere at normal pressure, and heating using an electric furnace or a metal bath whose temperature is adjusted to 340°C, and a method of heating inside a viscometer at 340°C and normal pressure in the atmosphere. The atmosphere during heat treatment is the atmosphere at normal pressure, which is close to the atmosphere during actual melt molding of the polyarylene sulfide copolymer, and the temperature of 340°C during heat treatment is close to the temperature frequently used during actual melt molding of the polyarylene sulfide copolymer. Therefore, it can be said that a polyarylene sulfide copolymer with a small Δη is a high-quality polyarylene sulfide copolymer with excellent melt molding processability in which the viscosity change during actual use is suppressed and the decrease in properties presumably due to the oxidative crosslinking reaction is suppressed.

[0041] Before heat treatment of the polyarylene sulfide copolymer, the lower limit of the complex melt viscosity η1 measured at 340 °C, an angular frequency of 6.28 rad / s, a shear stress of 1,000 Pa, and under a non-oxidizing atmosphere at normal pressure is preferably 0.1 Pa·s or more, more preferably 1 Pa·s or more, still more preferably 30 Pa·s or more, even more preferably 50 Pa·s or more, and yet even more preferably 70 Pa·s or more. When the lower limit of the complex melt viscosity η1 is within this range, the mechanical properties of the polyarylene sulfide copolymer tend to be excellent. The upper limit of the complex melt viscosity η1 can be exemplified as 100,000 Pa·s or less, preferably 50,000 Pa·s or less, more preferably 10,000 Pa·s or less, still more preferably 2,000 Pa·s or less, even more preferably 1,000 Pa·s or less, and yet even more preferably 500 Pa·s or less. When the upper limit of the complex melt viscosity η1 is within this range, the viscosity of the polyarylene sulfide copolymer is relatively low, and it tends to have excellent melt molding processability.

[0042] After the polyarylene sulfide copolymer is heat-treated at 340 °C for 20 minutes under normal pressure in the atmosphere, the upper limit of the complex melt viscosity η2 measured at 340 °C, an angular frequency of 6.28 rad / s, a shear stress of 1,000 Pa, and under the atmosphere at normal pressure only needs to satisfy that the viscosity change rate Δη represented by the above formula (1) is 10 times or less. From the viewpoint of excellent melt molding processability and excellent quality stability, it is preferably 10,000 Pa·s or less, more preferably 8,000 Pa·s or less, still more preferably 6,000 Pa·s or less, even more preferably 4,000 Pa·s or less, and yet even more preferably 2,000 Pa·s or less.

[0043] After heat-treating the polyarylene sulfide copolymer in the atmosphere at normal pressure at 340°C for 60 minutes, the complex viscosity η3 measured at 340°C, an angular frequency of 6.28 rad / s, and a shear stress of 1,000 Pa is preferably 10,000 Pa·s or less, more preferably 8,000 Pa·s or less, still more preferably 6,000 Pa·s or less, even more preferably 4,000 Pa·s or less, and still even more preferably 2,000 Pa·s or less. When the upper limit of the complex viscosity η3 after heat treatment is within this range, the melt molding processability is excellent and the quality stability tends to be excellent.

[0044] The polyarylene sulfide copolymer has a weight loss rate ΔW represented by the following formula (2) of 0.5% or less, preferably 0.4% or less, and more preferably 0.3% or less. ΔW=(W1-W2) / W1×100···(2) (Here, ΔW is the weight loss rate (%), W1 is the sample weight at the time of reaching 100°C when the temperature is raised from 30°C to 320°C at a rate of 10°C / min in a non-oxidizing atmosphere at normal pressure, and W2 is the sample weight after isothermal holding for 60 minutes after reaching 320°C.)

[0045] When ΔW exceeds 0.5%, the amount of gas generated during melt molding is large, dirt on the equipment and voids in the molded product are likely to occur, and productivity and mechanical properties are inferior. The lower limit of ΔW is desirably 0%, but in the polyarylene sulfide copolymer of the present invention, for example, 0.01% or more can be exemplified.

[0046] The heating conditions and heating temperature for obtaining the weight loss rate are in the temperature range frequently used when melt molding the polyarylene sulfide copolymer. Therefore, it can be said that a polyarylene sulfide copolymer with a small weight loss rate is a high-quality polyarylene sulfide copolymer that has a small amount of gas generation during actual use, less contamination of equipment, is less likely to generate voids in the molded product, and tends to have excellent productivity and mechanical properties.

[0047] The weight reduction rate can be determined by general thermogravimetric analysis. In this analysis, the atmosphere is usually a nitrogen atmosphere at normal pressure. The nitrogen atmosphere means an atmosphere in which nitrogen is present such that the oxygen concentration in the gas phase in contact with the sample is 5% by volume or less. Also, normal pressure means atmospheric pressure, that is, a pressure condition in the vicinity of 101.3 kPa in absolute pressure.

[0048] Further, it is preferable that the polyarylene sulfide copolymer also has a small amount of gas generation when heated under conditions where oxygen is present, such as under atmospheric conditions. The side reactions of the polyarylene sulfide copolymer by a mechanism different from that of the general polyarylene sulfide described above are difficult to qualitatively and quantitatively analyze and are not clear at present, but cross-linking reactions and decomposition reactions related to the structure contained in the polyarylene sulfide copolymer are considered. Also, cross-linking reactions and decomposition reactions related to the structure contained in the polyarylene sulfide copolymer and oxygen are considered. When heated under conditions where oxygen is present, such as under atmospheric conditions, generation of carbon dioxide and sulfur dioxide may be observed, and it is presumed that this is generated due to cross-linking reactions and decomposition reactions related to the structure contained in the polyarylene sulfide copolymer and oxygen. The polyarylene sulfide copolymer of the present invention preferably has a small amount of generation of these carbon dioxide and sulfur dioxide.

[0049] The amount of gas generation in the presence of oxygen simulating atmospheric conditions can be quantified by thermodesorption gas analysis (TPD-MS) when the temperature is raised from room temperature to 340 °C at a rate of 50 °C / min and then held at 340 °C for 60 minutes in an atmosphere of a dry gas in which 20% (volume ratio) of oxygen is mixed with an inert gas. Examples of the inert gas include nitrogen, helium, argon, etc., and by using these inert gases, the amount of gas generation as described below can be quantified. Also, as the MS apparatus, a quadrupole type or a magnetic field type mass spectrometer capable of acquiring mass number information from a mass number of about 2 to 500 at an arbitrary acquisition interval can be used for evaluation.

[0050] In the above heat generation gas analysis, the amount of carbon dioxide generated from the polyarylene sulfide copolymer is preferably 0.8% by weight or less, more preferably 0.7% by weight or less, still more preferably 0.6% by weight or less, even more preferably 0.5% by weight or less, and even still more preferably 0.4% by weight or less. Further, the amount of sulfur dioxide generated is preferably 0.6% by weight or less, more preferably 0.5% by weight or less, still more preferably 0.4% by weight or less, and even more preferably 0.3% by weight or less. Furthermore, when the polyarylene sulfide copolymer is heated under conditions where oxygen is present, such as under atmospheric conditions, generation of water may be observed. At present, it is impossible to determine whether the water is derived from the reaction of unreacted amino groups, carboxyl groups or acid anhydride groups, or from side reactions, but the amount of water generated is preferably 0.6% by weight or less, more preferably 0.5% by weight or less, and still more preferably 0.4% by weight or less. These gas generation amounts serve as indicators of the stability during melt residence. When within this range, the melt molding processability is excellent and the quality stability tends to be excellent.

[0051] The polyarylene sulfide copolymer preferably has a melting point of 300°C or lower, more preferably 290°C or lower, still more preferably 280°C or lower, and even more preferably 270°C or lower. When the melting point is within this range, the melt molding process tends to be facilitated. The melting point is determined as the value of the melting peak temperature detected when the temperature is raised from 0°C to 340°C at a rate of 20°C / min using a differential scanning calorimeter, held at 340°C for 1 minute, cooled to 100°C at a rate of 20°C / min, held at 100°C for 1 minute, and then the temperature is raised again to 340°C at a rate of 20°C / min. The melting point can be adjusted by selecting the molecular weight of the arylene sulfide units in the polyarylene sulfide copolymer or by selecting the structure of the copolymerization components.

[0052] The crystallization temperature of the polyarylene sulfide copolymer is preferably 165°C or higher, more preferably 170°C or higher, still more preferably 180°C or higher, and even more preferably 190°C or higher. When the crystallization temperature is within this range, the crystallization rate is sufficient during melt molding of the polyarylene sulfide copolymer or during production of a resin composition by blending a filler and / or other additives, resulting in excellent productivity. Also, the crystallization of the obtained molded article or resin composition is sufficient, and it tends to have excellent mechanical properties and chemical resistance. There is no particular upper limit to the crystallization temperature, but generally, a range of 235°C or lower can be exemplified. The crystallization temperature is defined as the value of the crystallization peak temperature detected when the temperature is raised from 0°C to 340°C at a rate of 20°C / min using a differential scanning calorimeter, held at 340°C for 1 minute, and then cooled to 100°C at a rate of 20°C / min. The crystallization temperature can be adjusted by selecting the molecular weight of the arylene sulfide unit in the polyarylene sulfide copolymer or by selecting the structure of the copolymer component. Further, by heating the polyarylene sulfide (A) and the compound (B) in the presence of an antioxidant and under mild heating conditions, the cross-linked structure due to an undesirable side reaction such as an oxidative cross-linked structure tends to be less, and a polyarylene sulfide copolymer having a relatively high crystallization temperature can be obtained.

[0053] The heat of fusion of the polyarylene sulfide copolymer is preferably 15 J / g or more, more preferably 20 J / g or more, and even more preferably 25 J / g or more. When the lower limit of the heat of fusion is within this range, the crystallinity of the polyarylene sulfide copolymer is high, and the mechanical properties and chemical resistance tend to be excellent. There is no particular limitation on the upper limit of the heat of fusion, but generally, a range of 70 J / g or less can be exemplified. The heat of fusion can be calculated from the melting peak detected when the temperature is raised from 0°C to 340°C at a rate of 20°C / min using a differential scanning calorimeter, then held at 340°C for 1 minute, cooled to 100°C at a rate of 20°C / min, held at 100°C for 1 minute, and then the temperature is raised to 340°C again at a rate of 20°C / min. The heat of fusion can be adjusted by selecting the molecular weight of the arylene sulfide unit in the polyarylene sulfide copolymer or by selecting the structure of the copolymer component. Further, by heating the polyarylene sulfide (A) and the compound (B) in the presence of an antioxidant and under mild heating conditions, the cross-linked structure due to an undesirable side reaction such as an oxidative cross-linked structure tends to be less, and a polyarylene sulfide copolymer having a relatively high heat of fusion can be obtained.

[0054] The lower limit of the weight average molecular weight of the polyarylene sulfide copolymer is preferably 10,000 or more, more preferably 20,000 or more, even more preferably 30,000 or more, and still more preferably 40,000 or more. When the lower limit of the weight average molecular weight is within this range, the mechanical properties of the polyarylene sulfide copolymer tend to be excellent. The upper limit of the weight average molecular weight can be exemplified as 200,000 or less, preferably 150,000 or less, more preferably 100,000 or less, and even more preferably 70,000 or less. When the upper limit of the weight average molecular weight is within this range, the viscosity of the polyarylene sulfide copolymer is relatively low, and the melt molding processability tends to be excellent.

[0055] The upper limit of the dispersity represented by the weight-average molecular weight / number-average molecular weight of the polyarylene sulfide copolymer is preferably 7.0 or less, more preferably 6.0 or less, and even more preferably 5.0 or less. When the upper limit of the dispersity is within this range, the amount of low-molecular-weight components contained in the polyarylene sulfide copolymer and the cross-linked structures due to unfavorable side reactions such as oxidation cross-linked structures tend to be small. The mechanical properties and chemical resistance of the polyarylene sulfide copolymer are excellent, and the amount of gas generated during melt molding processing also tends to be small. The lower limit of the dispersity is theoretically 1.0, which means that the polyarylene sulfide copolymer has a single molecular weight at this time, but usually it is 2.0 or more. The weight-average molecular weight and number-average molecular weight can be calculated in terms of polystyrene by gel permeation chromatography (GPC), which is a kind of size exclusion chromatography (SEC) equipped with a differential refractive index detector, for example. The dispersity can be adjusted by the conditions for heating the polyarylene sulfide (A) and the compound (B). By heating the polyarylene sulfide (A) and the compound (B) in the presence of an antioxidant and by using mild heating conditions, unfavorable side reactions typified by cross-linking reactions and decomposition reactions can be suppressed, and a polyarylene sulfide copolymer with a relatively small dispersity can be obtained.

[0056] The loss tangent tanδ represented by the following formula (3) of the polyarylene sulfide copolymer, measured at 340 °C, an angular frequency of 6.28 rad / s, a shear stress of 1,000 Pa, and under a non-oxidizing atmosphere at normal pressure, usually exceeds 1, preferably 3 or more, more preferably 5 or more, even more preferably 10 or more, still more preferably 15 or more, and even more preferably 20 or more. When tanδ is within this range, the viscosity is greater, showing liquid-like behavior, and the melt molding processability tends to be excellent. tanδ = loss elastic modulus / storage elastic modulus ··· (3)

[0057] The tanδ can be adjusted by selecting the molecular weight of the arylene sulfide unit in the polyarylene sulfide copolymer or by selecting the structure of the copolymer component. Further, by heating the polyarylene sulfide (A) and the compound (B) in the presence of an antioxidant and under mild heating conditions, the crosslinked structure due to an undesirable side reaction such as an oxidative crosslinked structure tends to be less, and a polyarylene sulfide copolymer having a relatively high tanδ can be obtained.

[0058] The polyarylene sulfide copolymer is heat-treated at 340°C in the atmosphere at normal pressure, and the time until the loss tangent tanδ represented by the above formula (3), measured at 340°C, angular frequency 6.28 rad / s, and shear stress 1,000 Pa, becomes 1 or less is preferably 5 minutes or more, more preferably 10 minutes or more, further preferably 15 minutes or more, still more preferably 20 minutes or more, and even more preferably 30 minutes or more. The time until tanδ becomes 1 or less is an index indicating the stability during melt residence time, and within this range, it tends to have excellent melt molding processability and excellent quality stability.

[0059] The polyarylene sulfide copolymer of the present invention is a polyarylene sulfide copolymer having excellent viscosity stability during heating, a small amount of generated gas, excellent melt molding processability, less likely to cause equipment contamination during molding and voids in the molded product, and is characterized by excellent mechanical properties.

[0060] As basic mechanical properties, which are also important in various applications of the polyarylene sulfide copolymer of the present invention described later, tensile strength and tensile elongation at break can be mentioned.

[0061] The tensile strength and the tensile elongation at break can be evaluated by the values measured under the conditions of a tensile speed of 1 mm / min, an ambient temperature of 23°C, and a relative humidity of 50% in accordance with ISO 527-1, -2 (2012) using a G-20 kNx universal testing machine on ISO 527-2-5A type test pieces obtained by injection molding a polyarylene sulfide copolymer. The lower limit of the tensile strength of the polyarylene sulfide copolymer is preferably 40 MPa or more, more preferably 50 MPa or more, further preferably 60 MPa or more, even more preferably 70 MPa or more, and still more preferably 80 MPa or more. There is no particular limitation on the upper limit of the tensile strength, but a range of usually 120 MPa or less can be exemplified. The lower limit of the tensile elongation at break of the polyarylene sulfide copolymer is preferably 4% or more, more preferably 5% or more, further preferably 6% or more, even more preferably 8% or more, and still more preferably 10% or more. There is no particular limitation on the upper limit of the tensile elongation at break, but a range of usually 40% or less can be exemplified. When the tensile strength and the tensile elongation at break are within this range, the polyarylene sulfide copolymer, the resin composition using the polyarylene sulfide copolymer, and the fiber-reinforced polyarylene sulfide copolymer composite base material can be suitably used for applications such as electric and electronic parts, mechanical related parts, automobile and vehicle related parts, and aviation and space related parts.

[0062] The polyarylene sulfide copolymer is a copolymer containing 70 mol% or more of a repeating unit of the formula -(Ar-S)- as an arylene sulfide unit, preferably a copolymer containing 80 mol% or more. Examples of Ar include units represented by the following formulas (I) to (XI), etc., and among them, the unit represented by formula (I) is particularly preferred.

[0063] [Chemical formula]

[0064] (R 3 , R 4 is a substituent selected from hydrogen, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 24 carbon atoms, a halogen group, and a reactive functional group, and R3 and R 4 may be the same or different.) As long as this repeating unit is the main constituent unit, a small amount of branched units or crosslinked units represented by the following formulas (XII) to (XIV) can be included. The copolymerization amount of these branched units or crosslinked units is preferably in the range of 0 to 1 mol% with respect to 1 mol of the unit of -(Ar-S)-.

[0065]

Chemical formula

[0066] (Here, Ar is the unit represented by the previous formulas (I) to (XI).)

[0067] The arylene sulfide unit may be any of a random copolymer, a block copolymer, and a mixture thereof containing the above repeating unit.

[0068] Typical examples of these include polyphenylene sulfide, polyphenylene sulfide sulfone, polyphenylene sulfide ketone, random copolymers thereof, block copolymers thereof, and mixtures thereof. Particularly preferred polyarylene sulfides include polyphenylene sulfide containing 80 mol% or more, particularly 90 mol% or more, of p-phenylene sulfide units represented by the following formula (XV) as the main constituent unit of the polymer

[0069]

Chemical formula

[0070] and the like.

[0071] The lower limit of the number average molecular weight of the arylene sulfide unit is preferably 1,000 or more, more preferably 1,500 or more, and still more preferably 2,000 or more. When the lower limit of the number average molecular weight of the arylene sulfide unit is within this range, the chemical resistance of the polyarylene sulfide copolymer tends to be high. The upper limit of the number average molecular weight of the arylene sulfide unit is preferably 10,000 or less, more preferably 6,000 or less, and still more preferably 4,000 or less. When the upper limit of the number average molecular weight of the arylene sulfide unit is within this range, the polyarylene sulfide copolymer tends to have excellent heat resistance. The number average molecular weight of the arylene sulfide unit in the polyarylene sulfide copolymer can be determined, for example, by measuring the molecular weight of the residue after treating the polyarylene sulfide copolymer in a 10% aqueous sodium hydroxide solution under reflux conditions for 5 hours. In order to make the number average molecular weight of the arylene sulfide unit in the polyarylene sulfide copolymer within the above range, in the production of the polyarylene sulfide copolymer, it is preferable to use the polyarylene sulfide (A) described later, having a number average molecular weight Mn of 1,000 or more and 10,000 or less. The number average molecular weight can be calculated in terms of polystyrene by gel permeation chromatography (GPC), which is a kind of size exclusion chromatography (SEC) equipped with a differential refractive index detector, for example.

[0072] Examples of the structure contained in the polyarylene sulfide copolymer as a copolymer component include structures containing an aromatic ring, preferably the structures represented by the above formulas (a) to (s), more preferably the structures represented by the above formulas (a) to (e), (i) and (j), and among them, the structure represented by the above formula (i) is particularly preferable. By including these structures, the resulting polyarylene sulfide copolymer tends to have excellent crystallinity.

[0073] In the polyarylene sulfide copolymer, the arylene sulfide unit composed of repeating units of -(Ar-S)- and the copolymer component are preferably linked by an imide group. By being linked by an imide group, high rigidity tends to be exhibited at high temperatures. The lower limit of the amount of imide groups is preferably 1 mol% or more, more preferably 2 mol% or more, and even more preferably 4 mol% or more with respect to sulfur atoms in the polyarylene sulfide copolymer. By setting the range as described above, a decrease in rigidity under high-temperature conditions can be sufficiently suppressed. The upper limit of the amount of imide groups is preferably 60 mol% or less, more preferably 40 mol% or less, even more preferably 30 mol% or less, and still more preferably 20 mol% or less. When the amount of imide groups increases, the chemical resistance of the resulting polyarylene sulfide copolymer tends to decrease, but by setting the range as described above, a polyarylene sulfide copolymer that exhibits sufficient chemical resistance and mechanical properties can be obtained. The amount of imide groups can be determined by calculation using the amount of functional groups contained in the polyarylene sulfide (A) used in the production of the polyarylene sulfide copolymer and the amount of functional groups contained in the compound (B), or can also be determined using the FT-IR spectrum or NMR spectrum of the polyarylene sulfide copolymer. The compound (B) will be described later.

[0074] [Method for producing polyarylene sulfide copolymer] The polyarylene sulfide copolymer of the present invention contains an amino group in the range of 400 μmol / g or more and 5,000 μmol / g or less, and has a weight loss rate of 5 wt% or less when heated at a heating rate of 10 °C / min from 30 °C to 320 °C. The polyarylene sulfide (A) and at least one compound (B) selected from the aforementioned formulas (a') to (u') are preferably produced by a method of heating at least in step 1 described later in the presence of the aforementioned antioxidant. Details will be described below.

[0075] [Polyarylene sulfide (A)] The polyarylene sulfide (A) is a homopolymer or copolymer having a repeating unit of the formula -(Ar-S)- as a main constituent unit. Here, having a main constituent unit means containing 70 mol% or more of the repeating unit. Examples of Ar include units represented by the above formulas (I) to (XI), etc., and among them, the unit represented by formula (I) is particularly preferred.

[0076] As long as this repeating unit is the main constituent unit, it can contain a small amount of branched units or cross-linked units represented by the above formulas (XII) to (XIV), etc. The copolymerization amount of these branched units or cross-linked units is preferably in the range of 0 to 1 mol% with respect to 1 mol of the unit of -(Ar-S)-.

[0077] The polyarylene sulfide (A) may be any of a random copolymer, a block copolymer, and a mixture thereof containing the above repeating unit.

[0078] Typical examples of these include polyphenylene sulfide, polyphenylene sulfide sulfone, polyphenylene sulfide ketone, their random copolymers, block copolymers, and mixtures thereof. Particularly preferred polyarylene sulfide includes polyphenylene sulfide containing 80 mol% or more, particularly 90 mol% or more of p-phenylene sulfide units represented by the above formula (XV) as the main constituent unit of the polymer.

[0079] The polyarylene sulfide (A) contains an amino group as a functional group. The position of the amino group may be in the main chain or at the end of the polyarylene sulfide, but introduction at the end is preferred because it is easier to control the reaction with other polymers or compounds having functional groups, and it is also preferred from the viewpoint of performing the copolymerization reaction with the compound (B) as described later. In the case of end introduction, it is preferably in the p-position with respect to S bonded to Ar. Also, a polyarylene sulfide having an amino group bonded to the above Ar can be exemplified as a preferred form. The above amino group is a structure derived from the compound (C), and details will be described later.

[0080] The lower limit of the amount of amino groups contained in the polyarylene sulfide (A) is preferably 400 μmol / g or more, more preferably 500 μmol / g or more, and even more preferably 600 μmol / g or more. When the lower limit of the amount of amino groups is within this range, the glass transition point of the polyarylene sulfide copolymer tends to be sufficiently high. Also, the upper limit of the amount of amino 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 upper limit of the amount of amino groups is within this range, a decrease in the chemical resistance of the polyarylene sulfide copolymer can be suppressed. The amino groups in the polyarylene sulfide (A) can be quantified by, for example, comparing the intensity of the absorption at 3382 cm -1 derived from the amino groups with the absorption at 1901 cm -1 derived from the benzene ring when analyzing the polyarylene sulfide (A) by FT-IR.

[0081] The number average molecular weight of the polyarylene sulfide (A) is preferably 1,000 or more, more preferably 2,000 or more. When the lower limit of the number average molecular weight is within this range, the chemical resistance of the polyarylene sulfide copolymer becomes high. The upper limit of the number average molecular weight is preferably 10,000 or less, more preferably 6,000 or less, and even more preferably 4,000 or less. When the upper limit of the number average molecular weight is within this range, the heat resistance of the polyarylene sulfide copolymer becomes high. The number average molecular weight can be calculated in terms of polystyrene by, for example, gel permeation chromatography (GPC), which is a type of size exclusion chromatography (SEC) equipped with a differential refractive index detector.

[0082] The polyarylene sulfide (A) preferably has a weight loss rate of 5 wt% or less, more preferably 4 wt% or less, and even more preferably 3 wt% or less when heated at a heating rate of 10 °C / min from 30 °C to 320 °C. The smaller the weight loss rate, the more preferable it is. As the lower limit, for example, 0.01 wt% or more can be exemplified. As a method for producing the polyarylene sulfide (A), when using the examples described later, even if a large amount of amino groups are introduced into the polyarylene sulfide (A), components that tend to become gas components during heating are less likely to remain.

[0083] The above weight loss rate can be determined by general thermogravimetric analysis. In this analysis, the atmosphere usually used is a nitrogen atmosphere at normal pressure. The nitrogen atmosphere and normal pressure are as described above. The weight loss rate of the polyarylene sulfide (A) is determined by performing thermogravimetric analysis while heating from room temperature to an arbitrary temperature of 320 °C or higher at a heating rate of 10 °C / min. This temperature range is a frequently used temperature region when actually using polyarylene sulfides typified by polyphenylene sulfide, or when melting, molding, or performing reactions. The weight loss rate in such an actual use temperature region serves as an index for the gas generation amount from the polyarylene sulfide (A) during actual use and the degree of contamination of equipment during molding processing and reactions. Therefore, it can be said that the polyarylene sulfide (A) with a low weight loss rate in such a temperature range is an excellent polyarylene sulfide (A) with high quality.

[0084] Also, as a method for producing the polyarylene sulfide (A), when using the examples described later, it is preferable because the crystallinity of the polyarylene sulfide copolymer obtained using the polyarylene sulfide (A) also tends to be excellent. This is also considered to be due to the fact that when the polyarylene sulfide (A) is produced by the production method described later, components that tend to become gas components during heating are less likely to remain.

[0085] The manufacturing method of the polyarylene sulfide (A) of the present invention will be specifically described below. Although not limited to the following method, in the present invention, it is a method for producing polyarylene sulfide by reacting at least a dihalogenated aromatic compound, an inorganic sulfidizing agent, and a compound (C) in an organic polar solvent in the presence of an alkali metal hydroxide. A method in which the compound (C) is present in the range of 0.04 mol or more and 0.5 mol or less with respect to 1 mol of the inorganic sulfidizing agent in the reaction vessel is preferable. Here, the compound (C) has at least one aromatic ring, and is a compound having an amino group and at least one functional group selected from a hydroxyl group, a salt of a hydroxyl group, a thiol group, and a salt of a thiol group on the one aromatic ring. When such a manufacturing method is selected, a functional group-containing polyarylene sulfide (A) with few impurities can be obtained, and the characteristic of a small gas generation amount can be obtained.

[0086] [Inorganic sulfidizing agent] The inorganic sulfidizing 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. Examples include alkali metal sulfides, alkali metal hydrosulfides, and hydrogen sulfide.

[0087] Specific examples of the alkali metal sulfide include, for example, lithium sulfide, sodium sulfide, potassium sulfide, rubidium sulfide, cesium sulfide, and mixtures of two or more of these. Among them, lithium sulfide and / or sodium sulfide are preferable, and sodium sulfide is more preferably used. These alkali metal sulfides can be used as hydrates or aqueous mixtures, or in the form of anhydrides. Note that the aqueous mixture refers to an aqueous solution, or a mixture of an aqueous solution and a solid component, or a mixture of water and a solid component. Since generally available inexpensive alkali metal sulfides are hydrates or aqueous mixtures, it is preferable to use alkali metal sulfides in such forms.

[0088] Specific examples of the alkali metal hydrosulfide include, for example, lithium hydrosulfide, sodium hydrosulfide, potassium hydrosulfide, rubidium hydrosulfide, cesium hydrosulfide, and mixtures of two or more of these. Among them, lithium hydrosulfide and / or sodium hydrosulfide are preferred, and sodium hydrosulfide is more preferably used.

[0089] In addition, an alkali metal sulfide prepared in the reaction system from an alkali metal hydrosulfide and an alkali metal hydroxide can also be used. Further, an alkali metal sulfide prepared by previously contacting an alkali metal hydrosulfide and an alkali metal hydroxide can also be used. These alkali metal hydrosulfides and alkali metal hydroxides can be used in the form of hydrates or aqueous mixtures, or in the form of anhydrides, and hydrates or aqueous mixtures are preferred from the viewpoints of availability and cost.

[0090] Furthermore, an alkali metal sulfide prepared in the reaction system from an alkali metal hydroxide such as lithium hydroxide or sodium hydroxide and hydrogen sulfide can also be used. Also, an alkali metal sulfide prepared by previously contacting an alkali metal hydroxide such as lithium hydroxide or sodium hydroxide and hydrogen sulfide can be used. Hydrogen sulfide can be used in any form of gaseous state, liquid state, or aqueous solution state without any problem.

[0091] [Compound (C)] The compound (C) used in the method for producing the polyarylene sulfide (A) has at least one aromatic ring, and has an amino group and at least one functional group selected from a hydroxyl group, a salt of a hydroxyl group, a thiol group, and a salt of a thiol group on the one aromatic ring. The compound (C) may be an aromatic compound having an amino group introduced as a functional group into the polyarylene sulfide and a hydroxyl group, a salt of a hydroxyl group, a thiol group, or a salt of a thiol group that reacts with a dihalogenated aromatic compound in the polymerization reaction step described later. Specific examples thereof include 2-aminophenol, 4-aminophenol, 3-aminophenol, 2-aminothiophenol, 4-aminothiophenol, 3-aminothiophenol, and compounds in which the hydroxyl group or thiol group of these compounds is a salt of an alkali metal or alkaline earth metal. From the viewpoint of reactivity, 4-aminophenol and 4-aminothiophenol can be exemplified as particularly preferred compounds. If it has the above characteristics, it is also possible to use a combination of two or more different compounds (C). When a compound having a hydroxyl group or a thiol group is used as the compound (C), it is a preferred embodiment to simultaneously use an equal amount of an alkali metal hydroxide. Further, when a compound in which the hydroxyl group or thiol group is in the form of a salt is used as the compound (C), it is possible to use it in the production of the polyarylene sulfide (A) after forming a salt in advance, or it is also possible to form a salt by a reaction in a reaction vessel.

[0092] The lower limit of the amount of compound (C) used is 0.04 mol or more, preferably 0.05 mol or more, more preferably 0.06 mol or more, still more preferably 0.08 mol or more, and even more preferably 0.1 mol or more, per 1 mol of the charged inorganic sulfidizing agent. It is preferable that the amount used is at least this value because the amino group can be sufficiently introduced into the polyarylene sulfide. The upper limit of the amount of compound (C) used is 0.5 mol or less, more preferably 0.45 mol or less, and still more preferably 0.4 mol or less, per 1 mol of the charged inorganic sulfidizing agent. It is preferable that the amount used is at most this value because it suppresses the decrease in the molecular weight of the polyarylene sulfide and the chemical resistance of the polyarylene sulfide copolymer tends to increase.

[0093] There is no particular specification regarding the addition timing of compound (C), and it may be added at any point in the pre-step, polymerization start, or polymerization reaction step described later, or it may be added in multiple portions. It is also possible to add compound (C) during the polymerization to adjust the molecular weight of the polymer. However, from the viewpoint of efficiently reacting compound (C) with the dihalogenated aromatic compound, it is more preferable that at least a part of compound (C) is added at the same stage as adding the dihalogenated aromatic compound to the reaction vessel.

[0094] [Dihalogenated aromatic compound] Examples of the dihalogenated aromatic compound used in the method for producing the polyarylene sulfide (A) include dihalogenated benzenes such as p-dichlorobenzene, o-dichlorobenzene, m-dichlorobenzene, p-dibromobenzene, o-dibromobenzene, m-dibromobenzene, 1-bromo-4-chlorobenzene, and 1-bromo-3-chlorobenzene, and dihalogenated aromatic compounds including compounds having substituents other than halogen such as 1-methoxy-2,5-dichlorobenzene, 1-methyl-2,5-dichlorobenzene, 1,4-dimethyl-2,5-dichlorobenzene, 1,3-dimethyl-2,5-dichlorobenzene, 2,5-dichlorobenzoic acid, 3,5-dichlorobenzoic acid, 2,5-dichloroaniline, 3,5-dichloroaniline, and bis(4-chlorophenyl)sulfide. Among them, dihalogenated aromatic compounds mainly composed of p-dihalogenated benzenes represented by p-dichlorobenzene are preferred. Particularly preferably, those containing 80 to 100 mol% of p-dichlorobenzene are more preferred, and those containing 90 to 100 mol% are even more preferred. It is also possible to use a combination of two or more different dihalogenated aromatic compounds.

[0095] The lower limit of the amount of the dihalogenated aromatic compound used is not particularly limited, but it is preferably 0.8 or more, more preferably 0.9 or more, and even more preferably 0.95 or more in terms of the [monomer ratio] represented by the following formula. By setting the [monomer ratio] within the above range, the polymerization reaction system can be stabilized and side reactions can be prevented, which is preferable. The upper limit of the amount used is not particularly limited, but it is preferably 1.2 or less, more preferably 1.1 or less, and even more preferably 1.05 or less in terms of the [monomer ratio]. By setting the [monomer ratio] within the above range, the amount of halogen remaining in the polyarylene sulfide can be reduced, which is preferable. In the following formula, [amount of dihalogenated aromatic compound], [amount of inorganic sulfidizing agent], and [amount of compound (C)] indicate the amounts of each compound used in the production of the polyarylene sulfide. [Monomer ratio] = [Amount of dihalogenated aromatic compound] / ([Amount of inorganic sulfidizing agent] + [Amount of compound (C)])

[0096] [Organic polar solvent] As the organic polar solvent used in the method for producing the polyarylene sulfide (A) 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; aprotic organic solvents represented by 1,3-dimethyl-2-imidazolidinone, N,N-dimethylacetamide, N,N-dimethylformamide, hexamethylphosphoric triamide, and mixtures thereof. These are preferably used because of their high reaction stability. Among these, N-methyl-2-pyrrolidone and 1,3-dimethyl-2-imidazolidinone are preferred, and N-methyl-2-pyrrolidone is more preferably used.

[0097] 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 sulfidizing agent. Using an amount of this value or more is preferable because polyarylene sulfide can be synthesized with a good yield. Also, 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 sulfidizing agent. Using an amount of this value or less is preferable because the generated gas when the obtained polyarylene sulfide (A) is heated can be reduced.

[0098] [Polymerization aid] It is also a preferred embodiment to use a polymerization aid in order to obtain a polyarylene sulfide with a relatively high degree of polymerization in a shorter time. Here, the polymerization aid means a substance having an action of increasing the viscosity of the obtained polyarylene sulfide. Specific examples of such a polymerization aid include, for example, organic carboxylates, water, alkali metal chlorides, organic sulfonates, alkali metal sulfates, alkaline earth metal oxides, alkali metal phosphates, and alkaline earth metal phosphates. These may be used alone or two or more of them may be used simultaneously. Among them, organic carboxylates, water, and alkali metal chlorides are preferred, and among the organic carboxylates, alkali metal carboxylates are preferred, and among the alkali metal chlorides, lithium chloride is preferred.

[0099] The above alkali metal carboxylate is represented by the general formula R(COOM) n (wherein R is an alkyl group, cycloalkyl group, aryl group, alkylaryl group or arylalkyl group having 1 to 20 carbon atoms. M is an alkali metal selected from lithium, sodium, potassium, rubidium and cesium. n is an integer of 1 to 3). The alkali metal carboxylate can also be used as a hydrate, anhydride or aqueous solution. Specific examples of the alkali metal carboxylate include, for example, lithium acetate, sodium acetate, potassium acetate, sodium propionate, lithium valerate, sodium benzoate, and mixtures thereof.

[0100] The alkali metal carboxylate may be synthesized by adding and reacting an organic acid and one or more compounds selected from the group consisting of alkali metal hydroxides, alkali metal carbonates and alkali metal bicarbonates in approximately equi-chemical equivalents. Among the above alkali metal carboxylates, lithium salts have high solubility in the reaction system and a large auxiliary effect but are expensive. On the other hand, potassium, rubidium and cesium salts are considered to have insufficient solubility in the reaction system, so sodium acetate, which is inexpensive and has appropriate solubility in the polymerization system, is most preferably used.

[0101] When these alkali metal carboxylates are used as a polymerization aid, the amount used is generally in the range of 0.01 mol to 2 mol, preferably in the range of 0.1 mol to 0.6 mol, and more preferably in the range of 0.2 mol to 0.5 mol, per 1 mol of the charged inorganic sulfidizing agent, in terms of obtaining a higher degree of polymerization.

[0102] Also, when water is used as a polymerization aid, the added amount is generally in the range of 0.3 mol to 15 mol, preferably in the range of 0.6 mol to 10 mol, and more preferably in the range of 1 mol to 5 mol, per 1 mol of the charged inorganic sulfidizing agent, in terms of obtaining a higher degree of polymerization.

[0103] 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 in combination, it is possible to achieve a higher molecular weight with a smaller amount of the alkali metal carboxylate and water.

[0104] There is no particular specification regarding the timing of adding these polymerization aids. They may be added at any time during the pre-process, polymerization start, or polymerization reaction process 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 pre-process or at the start of polymerization, from the viewpoint of easy addition. Also, when using water as a polymerization aid, it is effective to add it during the polymerization reaction process after charging the dihalogenated aromatic compound.

[0105] [Polymerization stabilizer] In order to stabilize the polymerization reaction system and prevent side reactions, a polymerization stabilizer can also be used. The polymerization stabilizer contributes to the stabilization of the polymerization reaction system and suppresses undesirable side reactions. One criterion for side reactions is the generation of thiophenol. The addition of a polymerization stabilizer can suppress the generation of thiophenol. Specific examples of the polymerization stabilizer include compounds such as alkali metal hydroxides, alkali metal carbonates, alkaline earth metal hydroxides, and alkaline earth metal carbonates. Among them, alkali metal hydroxides such as sodium hydroxide, potassium hydroxide, and lithium hydroxide are preferred. Since the above-mentioned alkali metal carboxylates also act as polymerization stabilizers, they are included as one of the polymerization stabilizers. Also, when using an alkali metal hydrosulfide as an inorganic sulfidizing agent, it was previously mentioned that it is particularly preferable to use an alkali metal hydroxide simultaneously. Here, an alkali metal hydroxide that is in excess with respect to the sulfidizing agent can also be a polymerization stabilizer.

[0106] These polymerization stabilizers can be used individually or in combination of two or more. The polymerization stabilizer is preferably used in a ratio of usually 0.02 mol to 0.2 mol, preferably 0.03 mol to 0.1 mol, more preferably 0.04 mol to 0.09 mol, per 1 mol of the charged inorganic sulfidizing agent. If this ratio is too small, the stabilizing effect is insufficient. On the contrary, if it is too large, it is economically disadvantageous and the polymer yield tends to decrease.

[0107] There is no particular specification regarding the timing of adding the polymerization stabilizer. It may be added at any time during the pre-step, polymerization start, or polymerization reaction step described later, or it may be added in multiple portions. However, it is more preferable to add it simultaneously at the start of the pre-step or the start of polymerization because it is easy to do so.

[0108] Next, regarding the preferred production method of the polyarylene sulfide of the present invention, the pre-step, polymerization reaction step, recovery step, and post-treatment step will be specifically described in order. Of course, the method is not limited to this.

[0109] [Pre-step] In the method for producing polyarylene sulfide (A), usually, an inorganic sulfidizing agent is used in the form of a hydrate. However, before adding the dihalogenated aromatic compound, it is preferable to raise the temperature of a mixture containing an organic polar solvent and the inorganic sulfidizing agent and remove an excessive amount of water out of the system.

[0110] Also, as described above, as the inorganic sulfidizing agent, an inorganic sulfidizing agent prepared in situ in the reaction system or in a tank separate from the polymerization tank from an alkali metal hydrosulfide and an alkali metal hydroxide can also be used. There are no particular limitations on this method, but desirably, in an inert gas atmosphere, in the temperature range of normal temperature to 150 °C, preferably from normal temperature to 100 °C, an alkali metal hydrosulfide and an alkali metal hydroxide are added to an organic polar solvent, and the temperature is raised to at least 150 °C or higher, preferably to 180 °C to 260 °C under normal pressure or reduced pressure to distill off water. A polymerization aid may be added at this stage, or compound (C) may be added. Further, in order to promote the distillation of water, the reaction may be carried out by adding toluene or the like.

[0111] At the end of the previous step, that is, the amount of water in the system before the polymerization reaction step is preferably 0.3 mol to 10.0 mol per mol of the charged sulfidizing agent. Here, the amount of water in the system is the amount obtained by subtracting the amount of water removed out of the polymerization system from the amount of water charged into the polymerization system. Also, the water to be charged may be in any form such as water, an aqueous solution, or crystal water.

[0112] [Polymerization reaction step] As a method for producing polyarylene sulfide (A), a method can be exemplified in which at least an inorganic sulfidizing agent, a dihalogenated aromatic compound, and compound (C) are reacted in an organic polar solvent within a temperature range of 200 °C or higher and less than 290 °C.

[0113] When starting the polymerization reaction, preferably in an inert gas atmosphere, an organic polar solvent, a sulfidizing agent, and a dihalogenated aromatic compound are mixed at a temperature in the range of room temperature to 240 °C, preferably 100 °C to 230 °C. The compound (C) and the polymerization aid may be added at this stage. The charging order of these raw materials may be arbitrary or simultaneous without any problem.

[0114] This mixture is usually heated to a temperature in the range of 200 °C to less than 290 °C. There is no particular limitation on the heating rate, but usually a rate of 0.01 °C / min to 5 °C / min is selected, and a range of 0.1 °C / min to 3 °C / min is more preferable.

[0115] Generally, finally, the temperature is 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.

[0116] A method of reacting at a constant temperature, for example, at 200 °C to 260 °C for a certain period of time and then raising the temperature to 270 °C to less than 290 °C before reaching the final temperature is effective for 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.

[0117] [Recovery step] In the method for producing the polyarylene sulfide (A), after the polymerization is completed, solids can be recovered from the polymerization reaction product containing the polymer, solvent, etc. Any known method may be adopted for the recovery method.

[0118] For example, after the polymerization reaction is completed, a method of gradually cooling to recover particulate polymer may be used. There is no particular limitation on the rate of gradual cooling at this time, but it is usually about 0.1 °C / min to 3 °C / min. It is not necessary to gradually cool at the same rate throughout the entire gradual cooling process, and a method of gradually cooling at a rate of 0.1 °C / min to 1 °C / min until the polymer particles crystallize and precipitate and then gradually cooling at a rate of 1 °C / min or more may be adopted.

[0119] Also, performing the above recovery under quenching conditions is one of the preferred methods. Among these recovery methods, a preferred method is the flash method. The flash method is a method in which the polymerization reaction product is flashed from a state of high temperature and high pressure (usually 250 °C or higher, 8 kg / cm 2 or higher) into an atmosphere of normal pressure or reduced pressure, and at the same time as recovering the solvent, the polymer is recovered in a powder form. The flash here means ejecting the polymerization reaction product from a nozzle. Specifically, the atmosphere for flashing includes nitrogen or steam at normal pressure, and the temperature thereof is usually selected in the range of 150 °C to 250 °C.

[0120] [Post-treatment step] After being produced through the above polymerization reaction step and recovery step, the polyarylene sulfide (A) can be subjected to acid treatment, hot water treatment, and washing with an organic solvent as post-treatment steps. From the viewpoint of impurity removal, it is preferable to perform any one of acid treatment, hot water treatment, and washing with an organic solvent in the post-treatment step, and it is more preferable to use two or more kinds of treatments in combination.

[0121] When performing acid treatment, it is as follows. The acid used for acid treatment is not particularly limited as long as it does not have an effect of decomposing polyarylene sulfide (A), and examples include acetic acid, hydrochloric acid, sulfuric acid, phosphoric acid, silicic acid, carbonic acid, and propionic 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. As a method of acid treatment, for example, there is 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 if necessary. When using a solution of an acid, the solution may be a solution using an organic solvent or an aqueous solution, but an aqueous solution is preferred from the viewpoint that the miscibility of the acid and the solubility of salts and basic components contained in the polyarylene sulfide tend to be relatively high. The water used is preferably distilled water or deionized water so as not to impair the effect of preferable chemical modification of the 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 the acid or salt remaining in the acid-treated polyarylene sulfide (A), it is preferable to wash several times with water or warm water. The water used for washing is preferably distilled water or deionized water so as not to impair the effect of preferable chemical modification of the polyarylene sulfide (A). When performing acid treatment, it is preferable because a higher molecular weight polyarylene sulfide copolymer tends to be obtained when obtaining a polyarylene sulfide copolymer using polyarylene sulfide (A).

[0122] When performing the hot water treatment, it is as follows. When heat-treating the polyarylene sulfide (A), the temperature of the hot water is preferably 100°C or higher, more preferably 120°C or higher, still more preferably 150°C or higher, and particularly preferably 170°C or higher. If it is less than 100°C, the effect of the preferable chemical modification of the polyarylene sulfide is small, which is not preferable. In order to exhibit the effect of the preferable chemical modification of the polyarylene sulfide (A) by the hot water treatment, the water used is preferably distilled water or deionized water. There are no particular restrictions on the operation of the hot water treatment. It can be carried out by a method of charging a predetermined amount of polyarylene sulfide (A) into a predetermined amount of water and heating and stirring in a pressure vessel, or a method of continuously performing the hot water treatment. The ratio of the polyarylene sulfide (A) to water is preferably such that there is more water. Usually, a bath ratio (weight of the cleaning liquid relative to the weight of the dry polyarylene sulfide (A)) of 200 g or less of the polyarylene sulfide (A) per 1 liter of water is selected. Also, in order to avoid the undesirable decomposition of the reactive functional groups at the ends, it is desirable that the treatment atmosphere be under an inert atmosphere. Further, in order to remove the remaining components, the polyarylene sulfide (A) after this hot water treatment operation is preferably washed several times with warm water.

[0123] When washing with an organic solvent, the procedure is as follows. The organic solvent used for washing the polyarylene sulfide (A) is not particularly limited as long as it does not have an effect of decomposing the 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, dichloroethylene, and perchloroethylene; alcohol solvents such as methanol, ethanol, propanol, butanol, pentanol, ethylene glycol, and propylene glycol; and aromatic hydrocarbon solvents such as benzene, toluene, and xylene can be mentioned as the organic solvents used for washing the polyarylene sulfide (A). Among these organic solvents, the use of N-methyl-2-pyrrolidone, acetone, dimethylformamide, and chloroform is preferred. Further, 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 can easily obtain relatively high solubility, are particularly preferred. These organic solvents may be used alone or in a mixture of two or more kinds, or may be used in mixture with water. As a method of washing with an organic solvent, for example, there is a method of immersing the polyarylene sulfide (A) in the organic solvent, and it is also possible to appropriately stir or heat if necessary. There is no particular limitation on the washing temperature when washing the polyarylene sulfide (A) with an organic solvent, and any temperature from room temperature to about 300 °C can be selected. Although the washing efficiency tends to increase as the washing temperature increases, usually a sufficient effect can be obtained at a washing temperature of room temperature to 150 °C. It is also possible to wash under pressure at a temperature above the boiling point of the organic solvent in a pressure vessel. Also, there is no particular limitation on the washing time. Depending on the washing conditions, in the case of batch washing, usually a sufficient effect can be obtained by washing for 5 minutes or more. It is also possible to wash continuously.An organic solvent is preferable because it reduces the amount of generated gas during heating of the polyarylene sulfide (A), and a high-molecular-weight polymer tends to be easily obtained when obtaining the polyarylene sulfide copolymer described below using the polyarylene sulfide (A).

[0124] [Thermal oxidation crosslinking treatment] The polyarylene sulfide (A) can also be used after being made into a high molecular weight by thermal oxidation crosslinking treatment by heating in an atmosphere where oxygen exists after the polymerization is completed or by heating with the addition of a crosslinking agent such as a peroxide. However, the number average molecular weight of the polyarylene sulfide (A) is preferably 10,000 or less.

[0125] [Compound (B)] The compound (B) is at least one compound selected from the above formulas (a') to (u').

[0126] X is either two carboxyl groups each bonded to two adjacent carbons or an acid anhydride group derived from the two carboxyl groups. From the perspective of reactivity when heating the above-described polyarylene sulfide (A) and the compound (B), X is preferably an acid anhydride group derived from two carboxyl groups each bonded to two adjacent carbons. 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, and R, R 1 , and R 2 may be the same or different. Hydrogen, a methyl group, an ethyl group, or a propyl group is preferable from the perspective of easy availability. Also, the aromatic ring of each compound may be a disubstituted or trisubstituted body, and the plurality of substituents X substituted on one aromatic ring may be the same or different.

[0127] Specific examples of the compound (B) include pyromellitic acid, 3,3',4,4'-thiodiphthalic acid, 3,3',4,4'-sulfonyldiphthalic acid, 3,3',4,4'-benzophenonetetracarboxylic acid, 3,3',4,4'-sulfinyldiphthalic acid, 3,3',4,4'-biphenyltetracarboxylic acid, 3,3',4,4'-tetracarboxyldiphenylmethane, 9,9-bis(3,4-dicarboxyphenyl)fluorene, naphthalene-1,4,5,8-tetracarboxylic acid, bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic acid, 3,4,9,10-perylenetetracarboxylic acid, pyromellitic dianhydride, 3,3',4,4'-thiodiphthalic anhydride, 3,3',4,4'-sulfonyldiphthalic anhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 3,3',4,4'-sulfinyldiphthalic anhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-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'-dicarboxybenzophenone, 4,4'-sulfinyldibenzoic acid, 4,4'-dicarboxybiphenyl. From the viewpoint of reactivity, 3,3',4,4'-thiodiphthalic anhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 3,3',4,4'-sulfinyldiphthalic anhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride, 4,4'-thiodibenzoic acid, 4,4'-dicarboxybenzophenone, 4,4'-sulfinyldibenzoic acid, 4,4'-dicarboxybiphenyl, pyromellitic acid, and pyromellitic dianhydride are preferably used.

[0128] [Heating Conditions of Polyarylene Sulfide (A) and Compound (B)] The polyarylene sulfide copolymer is preferably produced by heating polyarylene sulfide (A) and at least one compound (B) in the presence of the above-mentioned antioxidant, at least in Step 1 described below.

[0129] When heating polyarylene sulfide (A) and compound (B), the ratio of the sum of half of the amount of carboxyl groups and the amount of acid anhydride groups in compound (B) to the amount of amino groups in polyarylene sulfide (A) (sum of half of the amount of carboxyl groups and the amount of acid anhydride groups / amount of amino groups) is preferably 0.75 or more and 1.35 or less. By setting this range, the resulting polyarylene sulfide copolymer tends to have a high molecular weight and exhibit sufficient mechanical properties and chemical resistance. The lower limit of the ratio of the sum of half of the amount of carboxyl groups and the amount of acid anhydride groups in compound (B) to the amount of amino groups in polyarylene sulfide (A) is preferably 0.75 or more, more preferably 0.8 or more, further preferably 0.9 or more, even more preferably 1.0 or more, and particularly preferably more than 1.02. Although the reason is not clear at present, when the lower limit of the ratio is within this range, the glass transition point is sufficiently high, and the polyarylene sulfide copolymer tends to be excellent in crystallinity and exhibit a high crystallization temperature, excellent mechanical properties and chemical resistance. The upper limit of the ratio of the sum of half of the amount of carboxyl groups and the amount of acid anhydride groups in compound (B) to the amount of amino groups in polyarylene sulfide (A) is preferably 1.35 or less, more preferably 1.25 or less, further preferably 1.2 or less, even more preferably 1.15 or less, and even further preferably 1.1 or less. When the upper limit of the ratio is within this range, the polyarylene sulfide copolymer tends to have a high molecular weight. Furthermore, although the reason is not clear at present, it is speculated that the amount of reactive carboxyl groups and acid anhydride groups is relatively small, and the viscosity change during the melt heat treatment of the polyarylene sulfide copolymer tends to be small.

[0130] The heating is preferably carried out in the presence of an antioxidant. The types and examples of the antioxidant are as described above.

[0131] The lower limit of the addition amount of the antioxidant when heating is preferably 0.01 part by weight or more, more preferably 0.05 part by weight or more, still more preferably 0.1 part by weight or more, even more preferably 0.3 part by weight or more, and still even more preferably 0.5 part by weight or more with respect to 100 parts by weight of the polyarylene sulfide (A) from the viewpoint of suppressing the crosslinked structure due to side reactions and significant increase in molecular weight during heating and when using the polyarylene sulfide copolymer obtained by heating. Further, the polyarylene sulfide copolymer obtained by heating contains the structures represented by the above formulas (a) to (s) different from general polyarylene sulfides, and may also contain amino groups derived from the polyarylene sulfide (A), carboxyl groups or acid anhydride groups derived from the compound (B). Therefore, it is presumed that a crosslinked structure and an increase in molecular weight due to side reactions with a mechanism different from that of general polyarylene sulfides occur. Therefore, it is more effective to have a higher content of the antioxidant than the content with respect to general polyarylene sulfides. The addition amount of the antioxidant is more effective at 0.3 part by weight or more, still more effective at 0.4 part by weight or more, and particularly effective at 0.5 part by weight or more with respect to 100 parts by weight of the polyarylene sulfide (A). The upper limit of the addition amount of the antioxidant when heating is preferably 10 parts by weight or less, more preferably 5 parts by weight or less, and still more preferably 3 parts by weight or less with respect to 100 parts by weight of the polyarylene sulfide (A) from the viewpoint of suppressing the amount of generated gas caused by the antioxidant and suppressing the deterioration of the mechanical properties of the polyarylene sulfide copolymer caused by containing the antioxidant.

[0132] The heating in the method for producing the polyarylene sulfide copolymer of the present invention can be carried out by using an ordinary polymerization reactor, of course, it can also be carried out in a mold for producing a molded article, or by using an extruder or a melt kneader. As long as it is a device equipped with a heating mechanism, it can be carried out without particular limitation, and known methods such as batch method and continuous method can be adopted. From the viewpoint of excellent productivity, it is preferable to use an extruder or a melt kneader. Here, the extruder is preferably a vent type extruder having one or more shafts. In the case of a multi-shaft extruder having two or more shafts, the meshing or non-meshing of the shafts, and the rotation direction of the shafts can be either the same direction or different directions. However, in the case of a twin-screw extruder, it is preferable that the shafts are meshed and rotated in the same direction from the viewpoints of melting performance and kneading performance.

[0133] When heating polyarylene sulfide (A) and at least one compound (B) in the presence of an antioxidant, it is preferable to perform at least Step 1. Step 1: Using an extruder having a main hopper, and downstream from the main hopper, a first kneading zone, a vent zone, and a second kneading zone are configured in this order, and the vent zone is provided at a position within 0.5L from the upstream end of the screw, melt-extrude polyarylene sulfide (A), compound (B), and an antioxidant.

[0134] The vent zone is a zone provided in the cylinder of the extruder and having vent holes at the openings, and is effective for removing volatile components generated when heating polyarylene sulfide (A) and compound (B).

[0135] The main volatile components in the present invention include water generated during the reaction of the amino group derived from polyarylene sulfide (A) with the carboxyl group or acid anhydride group derived from compound (B). In addition, volatile components contained in polyarylene sulfide (A), unreacted substances or decomposition products of compound (B), unreacted substances or decomposition products of the antioxidant, by-products generated during the reaction of polyarylene sulfide (A) and compound (B), etc. may also be removed.

[0136] By melt-extruding using an extruder having a vent zone, the polyarylene sulfide copolymer tends to have a high molecular weight, the viscosity change during melt heat treatment is small, and the amount of gas generated tends to be small. Qualitative and quantitative analysis of the above volatile components is difficult, and the reason is not clear at present. However, by efficiently removing water, which is the main volatile component, the reaction between the amino group derived from the desirable polyarylene sulfide (A) and the carboxyl group or acid anhydride group derived from the compound (B) proceeds easily, side reactions are easily suppressed, and impurities are also easily removed.

[0137] The vent zone in Step 1 is provided at a position within 0.5L from the upstream end of the screw, preferably at a position within 0.4L, and more preferably at a position within 0.3L. Here, L is the length of the screw of the extruder. Since the atmospheric vent zone is at the above position of the screw, it is considered that volatile components can be efficiently removed in the initial stage of the reaction where the amount of amino groups in the polyarylene sulfide (A), half of the amount of carboxyl groups in the compound (B), and the total amount of acid anhydride groups are large and the amount of volatile components generated is relatively large. However, the polyarylene sulfide copolymer tends to have a high molecular weight, the viscosity change during melt heat treatment is small, and the amount of gas generated tends to be small.

[0138] The vent of the vent zone may be an atmospheric vent or a vacuum vent. However, between the first kneading zone and the second kneading zone, there is a zone where the reaction between the functional groups derived from the polyarylene sulfide (A) and the functional groups derived from the compound (B) may not proceed sufficiently, and there is a concern that the polyarylene sulfide copolymer may be easily vented up when the viscosity is relatively low. Therefore, the vent zone is preferably an atmospheric vent zone. When the viscosity of the polyarylene sulfide copolymer is sufficiently high or the degree of vacuum can be adjusted, a vacuum vent may be used.

[0139] There is no particular limitation on the length of L. However, the L / D of the extruder in the present invention can be exemplified as 30 to 80. Here, D is the diameter of the screw of the extruder. By setting L / D to 30 or more, an extruder configuration for performing Step 1 can be obtained, and the heating time for allowing the reaction between the amino group derived from polyarylene sulfide (A) and the carboxyl group or acid anhydride group derived from compound (B) to proceed can be ensured. By setting L / D to 80 or less, the heating time does not become too long, and side reactions and an excessive increase in the melt complex viscosity can be suppressed.

[0140] The vent zone in Step 1 depends on the L / D of the extruder. In order to provide it at the above-described preferred position, it is preferably located within 40D of the screw length from the upstream end of the screw, more preferably within 30D, even more preferably within 20D, still more preferably within 15D, and particularly preferably within 10D. The lower limit can be exemplified as 5D or more from the upstream end of the screw in order to provide a vent zone.

[0141] Also, although it is preferable to provide at least one vent zone at the above position, in order to enhance the effect of the vent zone, a vent zone may be further provided at a position downstream of the second kneading zone.

[0142] Polyarylene sulfide (A), compound (B), and the antioxidant may be supplied from the main hopper or may be supplied using a side feeder. However, from the viewpoint of suppressing crosslinked structures and an increase in molecular weight due to side reactions in the reaction between the amino group derived from polyarylene sulfide (A) and the carboxyl group or acid anhydride group derived from compound (B), it is preferable to supply the antioxidant from the main hopper, and it is preferable to supply at least a part of polyarylene sulfide (A) and / or at least a part of compound (B), as well as the antioxidant, from the main hopper.

[0143] The lower limit of the heating temperature can be exemplified as 200 °C or higher, preferably 230 °C or higher, and more preferably 250 °C or higher. By setting the lower limit of the heating temperature within such a range, the reaction between the amino group derived from polyarylene sulfide (A) and the carboxyl group or acid anhydride group derived from compound (B) can be easily promoted, and by setting it to a temperature equal to or higher than the temperature at which polyarylene sulfide (A) melts, the reaction tends to be completed in a shorter time. Since the melting temperature of polyarylene sulfide (A) varies depending on the composition and molecular weight of polyarylene sulfide (A) and the environment during heating, it cannot be uniquely indicated. However, it can be grasped, for example, by analyzing polyarylene sulfide (A) with a differential scanning calorimeter. As the upper limit of the heating temperature, 400 °C or lower can be exemplified, preferably 380 °C or lower, more preferably 370 °C or lower, and even more preferably 360 °C or lower. By setting the upper limit of the heating temperature within such a range, undesirable side reactions such as crosslinking reactions and decomposition reactions between polyarylene sulfides (A) or between the resulting polyarylene sulfide copolymers can be suppressed, and the deterioration of the properties of the resulting polyarylene sulfide copolymer can be suppressed.

[0144] Furthermore, in step 1, from the viewpoint of suppressing the volatilization of low molecular weight substances contained in polyarylene sulfide (A), compound (B), and low molecular weight substances contained in the polyarylene sulfide copolymer, which are present in a large amount particularly in the initial stage of the reaction in the heating system, and suppressing side reactions more effectively, the heating temperature in step 1 is particularly preferably 320 °C or lower.

[0145] The heating time varies depending on the composition and molecular weight of the polyarylene sulfide (A) and the environment during heating, and thus cannot be uniquely specified. However, it is preferably set so that the above-described side reactions hardly occur. As the lower limit of the heating time, 0.1 minute or more can be exemplified, preferably 1 minute or more, more preferably 2 minutes or more, and even more preferably 3 minutes or more. By setting the lower limit of the heating time within such a range, the reaction between the amino group derived from the polyarylene sulfide (A) and the carboxyl group or acid anhydride group derived from the compound (B) can proceed more sufficiently. As the upper limit of the heating time, 100 hours or less can be exemplified, preferably 20 hours or less, more preferably 10 hours or less, and even more preferably 1 hour or less. By setting the upper limit of the heating time within such a range, it is excellent in economy and tends to avoid the above-described side reactions.

[0146] Heating can be carried out either in the absence of a solvent or in the presence of a solvent. When carried out in the presence of a solvent, the solvent is not particularly limited as long as it does not substantially cause unfavorable side reactions such as decomposition or crosslinking of the resulting polyarylene sulfide copolymer. The solvent can be used as one kind or a mixture of two or more kinds. On the other hand, from the viewpoint of efficiently obtaining the polyarylene sulfide copolymer, it is preferable to carry out the process under substantially solvent-free conditions. Also, from the viewpoint of preventing contamination and deterioration of properties due to the generated gas when melt-molding and processing the obtained polyarylene sulfide copolymer, it is preferable to carry out the process under substantially solvent-free conditions. Here, the substantially solvent-free condition means that the solvent in the system for heating the polyarylene sulfide (A) and the compound (B) is 10% by weight or less, and preferably 3% by weight or less.

[0147] The atmosphere during heating may be under the atmosphere. From the perspective that it tends to suppress unfavorable side reactions such as cross-linking reactions and decomposition reactions between polyarylene sulfides (A) or between the produced polyarylene sulfide copolymers, etc., a non-oxidizing atmosphere is also preferable. The non-oxidizing atmosphere refers to an atmosphere in which the oxygen concentration in the gas phase is 5% by volume or less, preferably 2% by volume or less, more preferably an atmosphere that substantially does not contain oxygen, that is, an inert gas atmosphere such as nitrogen, helium, argon, etc. Among these, a nitrogen atmosphere is preferable particularly from the aspects of economy and ease of handling.

[0148] When heating polyarylene sulfide (A) and compound (B) in the presence of an antioxidant, after step 1, it is preferable to perform step 2 of further melt-extruding the obtained melt-extruded product with an extruder having a vacuum vent.

[0149] By using a vacuum vent to perform heating under reduced pressure conditions, it tends to suppress unfavorable side reactions such as cross-linking reactions and decomposition reactions between polyarylene sulfides (A) or between the produced polyarylene sulfide copolymers, etc., and is effective for efficiently removing volatile components generated when heating polyarylene sulfide (A) and compound (B). Also, the polyarylene sulfide copolymer tends to have a high molecular weight, the viscosity change during melt heat treatment is small, and the gas generation amount tends to be small. The qualitative and quantitative analysis of the above-mentioned volatile components is difficult, and the reason is not clear at present. However, by efficiently removing water, which is the main volatile component, the reaction between the functional groups derived from polyarylene sulfide (A), which is a desirable reaction, and the functional groups derived from compound (B) tends to proceed, side reactions are easily suppressed, and impurities are also easily removed. This is presumably the reason.

[0150] The term "under reduced pressure conditions" means that the system in which the reaction is carried out is at a pressure lower than atmospheric pressure. As the upper limit of the pressure, 50 kPa or less is preferable, 30 kPa or less is more preferable, 20 kPa or less is even more preferable, and 10 kPa or less is still more preferable. By setting the upper limit of the pressure within such a range, the above-described effects can be obtained. As the lower limit of the pressure, 0.1 kPa or more can be exemplified. By setting the lower limit of the pressure to 0.1 kPa or more, it is possible to avoid the load on the reaction apparatus due to excessive reduction of the pressure.

[0151] There is no particular limitation on the position of the vacuum vent zone of the extruder for carrying out Step 2. However, when it is provided on the upstream side, the reaction between the functional groups derived from the polyarylene sulfide (A) and the functional groups derived from the compound (B) may not proceed sufficiently, and there is a concern that when the viscosity of the polyarylene sulfide copolymer is relatively low, it is likely to vent up. Therefore, it is preferably provided at a position 0.5 L or more downstream from the upstream end of the screw. After removing the volatile components with a downstream vacuum vent, a configuration in which it is discharged is common.

[0152] Step 1 and Step 2 may be carried out by providing a configuration capable of both Step 1 and Step 2 in a single extruder, or Step 2 may be carried out again after only Step 1 is carried out.

[0153] When Step 2 is carried out again after only Step 1 is carried out, it is preferable to advance the reaction between the functional groups derived from the polyarylene sulfide (A) and the functional groups derived from the compound (B) in Step 1 and increase the viscosity of the melt extrudate to such an extent that it is difficult to vent up in Step 2. Therefore, the weight average molecular weight of the melt extrudate obtained in Step 1, which is melt extruded in Step 2, is preferably 10,000 or more, more preferably 20,000 or more, and even more preferably 30,000 or more.

[0154] In Step 2, the amounts of low molecular weight substances contained in polyarylene sulfide (A) which may be present in relatively large amounts in Step 1, which is the initial stage of the reaction, compound (B), and low molecular weight substances contained in these reactants are reduced. Therefore, the heating temperature in Step 2 can be higher than that in Step 1. From the viewpoint of promoting the reaction between the functional groups derived from polyarylene sulfide (A) and the functional groups derived from compound (B) and removing volatile components more efficiently, the heating temperature in Step 2 preferably exceeds the heating temperature in Step 1. Although it depends on the heating temperature in Step 1, 320°C or higher is more preferable, 330°C or higher is further preferable, 340°C or higher is even more preferable, and 350°C or higher is even further preferable. The upper limit of the heating temperature in Step 2 is particularly preferably 370°C or lower from the viewpoint of suppressing undesirable side reactions typified by the crosslinking reaction and decomposition reaction of the polyarylene sulfide copolymer and suppressing the deterioration of the properties of the obtained polyarylene sulfide copolymer.

[0155] The time for heating in Step 2 cannot be uniquely specified because it varies depending on the abundance and molecular weight of the reactants of polyarylene sulfide (A) and compound (B) in Step 2, the abundance of the functional groups derived from polyarylene sulfide (A) and the functional groups derived from compound (B), the abundance of polyarylene sulfide (A) and compound (B), and the environment during heating. However, it is preferably set so that the above-described side reactions do not occur as much as possible. As the lower limit of the heating time, 0.1 minute or more can be exemplified, 1 minute or more is preferable, 2 minutes or more is more preferable, and 3 minutes or more is further preferable. By setting the lower limit of the heating time within such a range, the reaction between the functional groups derived from polyarylene sulfide (A) and the functional groups derived from compound (B) can proceed more sufficiently. As the upper limit of the heating time, 100 hours or less can be exemplified, 20 hours or less is preferable, 10 hours or less is more preferable, and 1 hour or less is further preferable. By setting the upper limit of the heating time within such a range, it is excellent in economy and tends to avoid the above-described side reactions.

[0156] Heating can be carried out either in the absence of a solvent or in the presence of a solvent. When carried out in the presence of a solvent, the solvent is not particularly limited as long as it does not substantially cause unfavorable side reactions such as decomposition or crosslinking of the resulting polyarylene sulfide copolymer. The solvent can be used as one kind or a mixture of two or more kinds. On the other hand, from the viewpoint of efficiently obtaining the polyarylene sulfide copolymer, it is preferably carried out under substantially solvent-free conditions. Also, from the viewpoint of preventing contamination and property degradation caused by generated gases during melt molding processing of the obtained polyarylene sulfide copolymer, it is preferably carried out under substantially solvent-free conditions. Here, substantially solvent-free conditions mean that the solvent in the heating system is 10% by weight or less, preferably 3% by weight or less.

[0157] The atmosphere during heating may be under the atmosphere. From the viewpoint of having a tendency to suppress unfavorable side reactions such as crosslinking reactions and decomposition reactions between polyarylene sulfides or between the resulting polyarylene sulfide copolymers, a non-oxidizing atmosphere is also preferable. Note that a non-oxidizing atmosphere means 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 an atmosphere substantially free of oxygen, that is, an inert gas atmosphere such as nitrogen, helium, or argon. Among these, a nitrogen atmosphere is particularly preferable from the viewpoints of economy and ease of handling.

[0158] The polyarylene sulfide copolymer of the present invention can be used as a polyarylene sulfide copolymer resin composition by blending a filler and other additives. The method of blending in the production of the resin composition is not particularly limited, but examples include supplying it to a known melt kneader such as a single-screw or twin-screw extruder, Banbury mixer, kneader, and mixing roll, and kneading at a processing temperature of the melting peak temperature of the polyarylene sulfide copolymer +5 to 100°C.

[0159] Examples of the filler include inorganic fillers and organic fillers.

[0160] Examples of the inorganic filler include fibrous inorganic fillers such as glass fiber, glass milled fiber, carbon fiber, potassium titanate whisker, zinc oxide whisker, calcium carbonate whisker, wollastonite whisker, aluminum borate whisker, alumina fiber, silicon carbide fiber, ceramic fiber, asbestos fiber, metal fiber, and basalt fiber; non-fibrous inorganic fillers such as talc, wollastonite, zeolite, sericite, mica, kaolin, clay, mica, ferrite, pyrophyllite, bentonite, aluminum silicate, silicon oxide, magnesium oxide, alumina, zirconium oxide, titanium oxide, iron oxide, magnesium oxide, calcium carbonate, magnesium carbonate, dolomite, calcium sulfate, barium sulfate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, glass beads, glass flakes, glass powder, ceramic beads, boron nitride, silicon nitride, silicon carbide, aluminum silicate, calcium silicate, silica, graphite, carbon black, and graphite.

[0161] Examples of the organic filler include fibrous organic fillers such as polyethylene fiber, polypropylene fiber, polyester fiber, polyamide fiber, polyaramid fiber, fluororesin fiber, thermosetting resin fiber, epoxy resin fiber, polyvinylidene chloride-based fiber, polyvinylidene fluoride-based fiber, and cellulose fiber; non-fibrous organic fillers such as ebonite powder, cork powder, and wood powder.

[0162] These inorganic fillers and organic fillers may be hollow. It is also possible to use two or more of these fillers in combination. Further, these fillers may be pretreated with a coupling agent such as an isocyanate-based compound, an organic silane-based compound, an organic titanate-based compound, an organic borane-based compound, and an epoxy compound before use.

[0163] The type of the filler is not specified, but considering the reinforcing effect of the filler as a resin composition, fibrous inorganic fillers such as glass fiber and carbon fiber are preferred. Carbon fiber has not only the effect of improving mechanical properties but also the effect of reducing the weight of the molded product. Further, when the filler is carbon fiber, the effect of improving the mechanical properties and chemical resistance of the resin composition is more significantly exhibited, which is more preferable. Among PAN-based, pitch-based, and rayon-based carbon fibers, PAN-based carbon fiber is preferred from the viewpoint of the balance between the strength and elastic modulus of the molded product.

[0164] In particular, a fiber-reinforced polyarylene sulfide copolymer composite substrate obtained by impregnating a continuous reinforcing fiber or a reinforcing fiber substrate in which discontinuous reinforcing fibers are dispersed with the polyarylene sulfide copolymer of the present invention has chemical resistance of polyarylene sulfide, high rigidity at high temperature, high processability when molding a molded product from the composite substrate, and high quality stability during processing.

[0165] For the polyarylene sulfide copolymer, for the purpose of modification, plasticizers such as olefin-based copolymers, alkoxysilane compounds, isocyanate-based compounds, organic titanate-based compounds, organic borane-based compounds, polyalkylene oxide oligomer-based compounds, thioether-based compounds, ester-based compounds, and organic phosphorus-based compounds, crystal nucleating agents such as talc, kaolin, organic phosphorus compounds, and polyether ether ketone, mold release agents such as montanic acid waxes, lithium stearate, and aluminum stearate, metal soaps, ethylene diamine·stearic acid·sebacic acid polycondensates, silicone-based compounds, colorant inhibitors such as hypophosphite, and additives such as lubricants, ultraviolet light absorbers, flame retardants, colorants, and foaming agents can also be blended.

[0166] [Fiber-Reinforced Polyarylene Sulfide Copolymer Composite Substrate] The fiber-reinforced polyarylene sulfide copolymer composite base material of the embodiment of the present invention is obtained by impregnating reinforcing fibers with a polyarylene sulfide copolymer. The reinforcing fibers may be continuous reinforcing fibers or a reinforcing fiber base material in which discontinuous reinforcing fibers are dispersed. The continuous reinforcing fibers are not particularly limited, and examples include fibers aligned in one direction, woven fabrics (cloth), knitted fabrics, braided cords, and tows. The reinforcing fiber base material in which discontinuous reinforcing fibers are dispersed is not particularly limited, and specific examples include non-woven fabrics, random mats, aggregates of chopped fibers, and the like.

[0167] As a method for impregnating the reinforcing fibers with the polyarylene sulfide copolymer, a known method can be used.

[0168] The type of the reinforcing fibers is not particularly limited, and examples include carbon fibers, metal fibers, organic fibers, and inorganic fibers. Two or more of these may be used.

[0169] Examples of the carbon fibers include PAN-based carbon fibers made from polyacrylonitrile (PAN) fibers as a raw material, pitch-based carbon fibers made from petroleum tar or petroleum pitch as a raw material, cellulose-based carbon fibers made from viscose rayon or cellulose acetate as a raw material, vapor-grown carbon fibers made from hydrocarbons as a raw material, and graphitized fibers thereof. Among these carbon fibers, PAN-based carbon fibers are preferably used in terms of excellent balance between strength and elastic modulus.

[0170] Examples of the metal fibers include fibers made of metals such as iron, gold, silver, copper, aluminum, brass, and stainless steel.

[0171] Examples of the organic fibers include fibers made of organic materials such as aramid, polybenzoxazole (PBO), polyphenylene sulfide, polyester, polyamide, and polyethylene. Examples of the aramid fibers include para-aramid fibers excellent in strength and modulus of elasticity, and meta-aramid fibers excellent in flame retardancy and long-term heat resistance. Examples of the para-aramid fibers include polyparaphenylene terephthalamide fibers, copolyparaphenylene-3,4'-oxydiphenylene terephthalamide fibers, etc., and examples of the meta-aramid fibers include polyphenylene isophthalamide fibers, etc. As the aramid fibers, para-aramid fibers having a higher modulus of elasticity than meta-aramid fibers are preferably used.

[0172] Examples of the inorganic fibers include fibers made of inorganic materials such as glass, basalt, silicon carbide, and silicon nitride. Examples of the glass fibers include E-glass fibers (for electricity), C-glass fibers (for corrosion resistance), S-glass fibers, T-glass fibers (high strength and high modulus of elasticity), etc. Basalt fiber is a fiber obtained by fiberizing the mineral basalt and is a fiber having extremely high heat resistance. Basalt generally contains 9 to 25% by weight of FeO or FeO 2 which is an iron compound, and 1 to 6% by weight of TiO or TiO 2 which is a titanium compound, but it is also possible to increase the amount of these components in the molten state and fiberize them.

[0173] The reinforcing fiber is usually composed of arranging one or a plurality of bundles in which a number of single fibers are bundled together.

[0174] Since the fiber-reinforced polyarylene sulfide copolymer composite base material of the present invention is often expected to serve as a reinforcing material, it is desirable to exhibit high mechanical properties. In order to exhibit high mechanical properties, it is preferable that the reinforcing fiber contains carbon fiber.

[0175] The fiber-reinforced polyarylene sulfide copolymer composite base material of the present invention has less fiber breakage during processing and can obtain high mechanical properties compared to a fiber-reinforced resin composition produced by melt-kneading reinforcing fibers and a thermoplastic resin. Therefore, it has been attempted to be used as a substitute for conventional metals in structural members in various industries such as automobiles, electric and electronic devices, housing, and aircraft. Polyphenylene sulfide, which is representative of polyarylene sulfide, is utilized in various industries by taking advantage of its excellent properties such as heat resistance, chemical resistance, high dimensional accuracy, and flame retardancy. However, its glass transition temperature is about 90°C, which is lower than the boiling point of water. Therefore, it has been difficult to apply a fiber-reinforced resin composite base material using polyphenylene sulfide to structural members, which are applications that require high reliability. However, in recent years, as the study of resinification for structural members has advanced, an improvement in heat resistance has been expected while having the excellent properties of polyphenylene sulfide. In the present invention, by using a polyarylene sulfide copolymer that has chemical resistance similar to polyphenylene sulfide, a glass transition temperature of 95°C or higher and 190°C or lower, and further excellent high-temperature rigidity, a highly reliable fiber-reinforced resin composite base material can be provided.

[0176] The impregnation state of the fiber-reinforced polyarylene sulfide copolymer composite base material can be evaluated by void observation. Regarding the void observation of the fiber-reinforced polyarylene sulfide copolymer composite base material, the fiber-reinforced polyarylene sulfide copolymer composite base material is cut, and the cross-section in the thickness direction of the fiber-reinforced polyarylene sulfide copolymer composite base material is observed as follows. A sample in which the fiber-reinforced polyarylene sulfide copolymer composite base material is embedded in an epoxy resin is prepared, and the sample is polished until the cross-section in the thickness direction of the fiber-reinforced polyarylene sulfide copolymer composite base material can be observed well. It is photographed at a magnification of 400 times with a digital microscope (VHX-7000 manufactured by Keyence) microscope (CCD). By measuring the area ratios of the normal part and the voids (void parts) of the photographed cross-section, the void ratio of the fiber-reinforced polyarylene sulfide copolymer composite base material can be calculated. The void ratio is preferably 10% or less, and more preferably 3% or less. When the void ratio is within this range, the mechanical properties of the fiber-reinforced polyarylene sulfide copolymer composite base material tend to be excellent.

[0177] The lower limit of the thickness of the fiber-reinforced polyarylene sulfide copolymer composite base material of the present invention is preferably 0.1 mm or more, and more preferably 0.2 mm or more. If the lower limit of the thickness is within this range, the productivity of the fiber-reinforced polyarylene sulfide copolymer composite base material and the molded product obtained using the same, and the yield during troubles can be improved. On the other hand, the upper limit of the thickness can be exemplified as 10 mm or less, preferably 1.5 mm or less, more preferably 1 mm or less, still more preferably 0.7 mm or less, and even more preferably 0.6 mm or less. If the upper limit of the thickness is within this range, it is easier to impregnate the reinforcing fibers with the polyarylene sulfide copolymer.

[0178] In addition, the volume content of the reinforcing fibers in the fiber-reinforced polyarylene sulfide copolymer composite base material of the present invention is preferably 20 to 70% by volume. In other words, it is preferable to contain 20 to 70% by volume of the reinforcing fibers with respect to the entire fiber-reinforced polyarylene sulfide copolymer composite base material (100% by volume). By containing 20% by volume or more of the reinforcing fibers, the strength of the molded article obtained using the fiber-reinforced polyarylene sulfide copolymer composite base material can be further improved. More preferably, it is 30% by volume or more, and even more preferably, it is 40% by volume or more. On the other hand, by containing 70% by volume or less of the reinforcing fibers, it becomes easier to impregnate the reinforcing fibers with the polyarylene sulfide copolymer. More preferably, it is 60% by volume or less, and even more preferably, it is 55% by volume or less. The volume content can be adjusted to a desired range by adjusting the input amounts of the reinforcing fibers and the polyarylene sulfide copolymer.

[0179] The volume content (Vf) of the reinforcing fibers in the fiber-reinforced polyarylene sulfide copolymer composite base material can be calculated by the following formula after measuring the mass W3 of the fiber-reinforced polyarylene sulfide copolymer composite base material, immersing it in 1-chloronaphthalene at 250°C to elute the polyarylene sulfide copolymer (D), and then measuring the mass W4 of the reinforcing fibers remaining as a residue.

[0180] Vf (% by volume) = (W4 / ρf) / {W4 / ρf + (W3 - W4) / ρr} × 100 ρf: Density of the reinforcing fibers (g / cm 3 ) ρr: Density of the polyarylene sulfide copolymer (g / cm 3 ) In addition, the fiber-reinforced polyarylene sulfide copolymer composite base material of the embodiment of the present invention can select a desired impregnation property according to its usage and purpose. For example, a prepreg with higher impregnation property, a semi-impregnated semi-prepreg, a fabric with low impregnation property, etc. can be mentioned. Generally, a molding material with higher impregnation property is preferable because a molded article with excellent mechanical properties can be obtained by molding in a short time.

[0181] [Polyarylene Sulfide Copolymer (D) Contained in the Fiber-Reinforced Polyarylene Sulfide Copolymer Composite Substrate] The fiber-reinforced polyarylene sulfide copolymer composite substrate of the present invention is manufactured using the polyarylene sulfide copolymer of the present invention, and the obtained fiber-reinforced polyarylene sulfide copolymer composite substrate contains polyarylene sulfide copolymer (D). Since the polyarylene sulfide copolymer may change during the manufacturing process of the fiber-reinforced polyarylene sulfide copolymer composite substrate, the characteristics of the polyarylene sulfide copolymer and the polyarylene sulfide copolymer (D) contained in the finally obtained fiber-reinforced polyarylene sulfide copolymer composite substrate may be different. Therefore, in the present invention, the polyarylene sulfide copolymer contained in the obtained fiber-reinforced polyarylene sulfide copolymer composite substrate is defined as polyarylene sulfide copolymer (D).

[0182] The glass transition point of polyarylene sulfide copolymer (D) is substantially the same as that of the polyarylene sulfide copolymer, but may change by high molecular weight due to the heating conditions during impregnation. The lower limit of the glass transition point is preferably 95 °C or higher, more preferably 100 °C or higher, and even more preferably 110 °C or higher. When the lower limit of the glass transition point is within this range, high rigidity can be obtained under high temperature conditions. The upper limit of the glass transition point is preferably 190 °C or lower, more preferably 180 °C or lower, and even more preferably 160 °C or lower. When the upper limit of the glass transition point is within this range, the chemical resistance of the fiber-reinforced polyarylene sulfide copolymer composite substrate increases. 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. In order to detect the glass transition point, it is necessary to use a fiber-reinforced polyarylene sulfide copolymer composite substrate obtained by quenching from the molten state.

[0183] The polyarylene sulfide copolymer (D) preferably has a melting point of 300°C or lower, more preferably 290°C or lower, still more preferably 280°C or lower, and even more preferably 270°C or lower. When the melting point is within this range, the melt molding process using the fiber-reinforced polyarylene sulfide copolymer composite base material tends to be facilitated. The melting point is determined as the value of the melting peak temperature detected when the fiber-reinforced polyarylene sulfide copolymer composite base material is heated from 0°C to 340°C at a rate of 20°C / min using a differential scanning calorimeter, held at 340°C for 1 minute, cooled to 100°C at a rate of 20°C / min, held at 100°C for 1 minute, and then heated to 340°C again at a rate of 20°C / min.

[0184] The crystallization temperature of the polyarylene sulfide copolymer (D) is preferably 165°C or higher, more preferably 170°C or higher, still more preferably 180°C or higher, even more preferably 190°C or higher, and still even more preferably 200°C or higher. When the crystallization temperature is within this range, when melt-molding the fiber-reinforced polyarylene sulfide copolymer composite base material, the crystallization rate tends to be fast and the productivity tends to be high, and the obtained molded article tends to have excellent mechanical properties and chemical resistance due to sufficient crystallization. There is no particular limitation on the upper limit of the crystallization temperature, but generally, a range of 235°C or lower can be exemplified. The crystallization temperature is determined as the value of the crystallization peak temperature detected when the fiber-reinforced polyarylene sulfide copolymer composite base material is heated from 0°C to 340°C at a rate of 20°C / min using a differential scanning calorimeter, held at 340°C for 1 minute, and cooled to 100°C at a rate of 20°C / min. By using the polyarylene sulfide copolymer of the present invention, there is a tendency for fewer crosslinked structures due to unfavorable side reactions such as oxidation crosslinked structures, and a fiber-reinforced polyarylene sulfide copolymer composite base material containing a polyarylene sulfide copolymer (D) having a relatively high crystallization temperature can be obtained.

[0185] The heat of fusion of the polyarylene sulfide copolymer (D) is preferably 15 J / g or more, more preferably 20 J / g or more, still more preferably 25 J / g or more, and even more preferably 30 J / g or more. When the lower limit of the heat of fusion is within this range, the crystallinity of the polyarylene sulfide copolymer (D) is high, and the mechanical properties and chemical resistance of the fiber-reinforced polyarylene sulfide copolymer composite base material tend to be excellent. There is no particular limitation on the upper limit of the heat of fusion, but generally, a range of 70 J / g or less can be exemplified. The heat of fusion can be calculated from the melting peak detected when the fiber-reinforced polyarylene sulfide copolymer composite base material is heated from 0°C to 340°C at a rate of 20°C / min using a differential scanning calorimeter, then held at 340°C for 1 minute, cooled to 100°C at a rate of 20°C / min, held at 100°C for 1 minute, and then heated to 340°C again at a rate of 20°C / min, and is calculated as the heat quantity per unit weight of the polyarylene sulfide copolymer (D) excluding the reinforcing fibers in the fiber-reinforced polyarylene sulfide copolymer composite base material. By using the polyarylene sulfide copolymer of the present invention, there is a tendency for fewer crosslinked structures due to unfavorable side reactions such as oxidation crosslinked structures, and a fiber-reinforced polyarylene sulfide copolymer composite base material containing a polyarylene sulfide copolymer (D) having a relatively high heat of fusion can be obtained.

[0186] The lower limit of the weight-average molecular weight of the polyarylene sulfide copolymer (D) is preferably 10,000 or more, more preferably 20,000 or more, still more preferably 30,000 or more, and even more preferably 40,000 or more. When the lower limit of the weight-average molecular weight is within this range, the mechanical properties of the fiber-reinforced polyarylene sulfide copolymer composite base material tend to be excellent. The upper limit of the weight-average molecular weight can be exemplified as 200,000 or less, preferably 150,000 or less, more preferably 100,000 or less, and still more preferably 80,000 or less. When the upper limit of the weight-average molecular weight is within this range, the viscosity of the polyarylene sulfide copolymer (D) is relatively low, and the melt molding processability of the fiber-reinforced polyarylene sulfide copolymer composite base material tends to be excellent. The weight-average molecular weight is a value calculated in terms of polystyrene by gel permeation chromatography (GPC), which is a kind of size exclusion chromatography (SEC).

[0187] The upper limit of the dispersity represented by the weight-average molecular weight / number-average molecular weight of the polyarylene sulfide copolymer (D) is preferably 7.0 or less, more preferably 6.0 or less, and still more preferably 5.0 or less. When the upper limit of the dispersity is within this range, the amount of low-molecular-weight components contained in the polyarylene sulfide copolymer (D) and the crosslinked structure due to unfavorable side reactions such as an oxidative crosslinked structure tend to be small. The mechanical properties and chemical resistance of the fiber-reinforced polyarylene sulfide copolymer composite base material are excellent, and the amount of gas generated during melt molding also tends to be small. The lower limit of the dispersity is theoretically 1.0, which means that the polyarylene sulfide copolymer (D) has a single molecular weight at this time, but usually it is 2.0 or more. The weight-average molecular weight and the number-average molecular weight can be calculated in terms of polystyrene by gel permeation chromatography (GPC), which is a kind of size exclusion chromatography (SEC) equipped with, for example, a differential refractive index detector.

[0188] By using the polyarylene sulfide copolymer of the present invention, the crosslinked structure due to an undesirable side reaction such as an oxidative crosslinked structure tends to be less, and a fiber-reinforced polyarylene sulfide copolymer composite base material containing a polyarylene sulfide copolymer (D) having a relatively high molecular weight and a small dispersity can be obtained.

[0189] The fiber-reinforced polyarylene sulfide copolymer composite base material of the present invention is laminated in one or more layers in an arbitrary configuration, and then molded by applying heat and / or pressure as necessary to obtain a molded article.

[0190] Examples of the method for applying heat and / or pressure include, for example, a press molding method in which a fiber-reinforced polyarylene sulfide copolymer composite base material laminated in an arbitrary configuration is placed in a mold or on a press plate, and then the mold or press plate is closed and pressurized; an autoclave molding method in which a molding material laminated in an arbitrary configuration is put into an autoclave and pressurized and heated; a bagging molding method in which a molding material laminated in an arbitrary configuration is wrapped with a film or the like, the inside is depressurized, and heated in an oven while pressurizing with atmospheric pressure; a wrapping tape method in which a tape is wound around a fiber-reinforced polyarylene sulfide copolymer composite base material laminated in an arbitrary configuration while applying tension, and heated in an oven; an internal pressure molding method in which a fiber-reinforced polyarylene sulfide copolymer composite base material laminated in an arbitrary configuration is placed in a mold, and a gas, liquid, or the like is injected into a core also placed in the mold to apply pressure. In particular, since a molded article with few voids in the obtained molded article and excellent appearance quality can be obtained, a molding method of pressing using a mold is preferably used.

[0191] As a press molding method, a fiber-reinforced polyarylene sulfide copolymer composite base material is previously placed in a mold, and pressure and heat are applied while closing the mold. Then, while keeping the mold closed, the fiber-reinforced polyarylene sulfide copolymer composite base material is cooled by cooling the mold to obtain a molded product. A hot press method or a stamping method can be employed, in which the fiber-reinforced polyarylene sulfide copolymer composite base material is previously heated by a heating device such as a far-infrared heater, a heating plate, a high-temperature oven, or dielectric heating to a temperature equal to or higher than the melting temperature of the polyarylene sulfide copolymer (D), the polyarylene sulfide copolymer (D) is melted and softened, and then it is placed on the mold that becomes the lower surface of the molding die. Next, the mold is closed and clamped, and then pressure cooling is performed. There is no particular limitation on the press molding method, but from the viewpoint of shortening the molding cycle and enhancing productivity, stamping is preferably used. The fiber-reinforced polyarylene sulfide copolymer composite base material and the molded product of the present invention can be integrally molded such as insert molding and outsert molding, or can be integrated using an adhesion method or an adhesive excellent in productivity such as a correction treatment by heating, thermal welding, vibration welding, or ultrasonic welding to obtain a composite.

[0192] As a molded product, a composite molded product in which at least a part of a fiber-reinforced polyarylene sulfide copolymer composite base material and a molded product containing a thermoplastic resin are joined is also preferable. There is no particular limitation on the molded product containing a thermoplastic resin (molding base material and molded product) integrated with the fiber-reinforced polyarylene sulfide copolymer composite base material of the present invention, and examples thereof include a resin material and a molded product, a metal material and a molded product, and an inorganic material and a molded product. Among them, a resin material and a molded product are preferable in terms of the adhesive strength with the fiber-reinforced polyarylene sulfide copolymer (D) in the present invention. The matrix resin of the molding material and the molded product integrated with the fiber-reinforced polyarylene sulfide copolymer composite base material of the present invention may be the same type of resin as the fiber-reinforced polyarylene sulfide copolymer composite base material and its molded product, or may be a different type of resin. In order to further increase the adhesive strength, it is preferably the same type of resin. When it is a different type of resin, it is more preferable to provide a resin layer at the interface.

[0193] The polyarylene sulfide copolymer of the present invention is excellent in heat resistance, chemical resistance, flame retardancy, electrical properties and mechanical properties, and can be formed into extruded products such as sheets, films, fibers and pipes by extrusion, as well as in injection molding, injection compression molding and blow molding applications.

[0194] Examples of the uses of the resin composition using the polyarylene sulfide copolymer of the present invention include electrical and electronic parts, audio equipment parts, household and office electrical product parts, machine-related parts, optical equipment, precision machine-related parts, plumbing parts, automotive and vehicle-related parts, aerospace-related parts and other various uses.

[0195] In addition, as the use of the fiber-reinforced polyarylene sulfide copolymer composite base material of the present invention, since it is particularly excellent in mechanical properties and also has a weight reduction effect, among the above, particularly electrical and electronic parts, machine-related parts, automotive and vehicle-related parts, aerospace-related parts and the like can be exemplified.

Examples

[0196] Hereinafter, the method of the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited only to these Examples.

[0197] [Measurement of glass transition temperature, melting point, heat of fusion and crystallization temperature] The glass transition temperature (Tg), melting point (Tm), heat of fusion (ΔHm), and crystallization temperature (Tmc) of the polyarylene sulfide copolymer were measured by a differential scanning calorimeter (DSC) using about 10 to 20 mg of an amorphous sample prepared by quenching from the molten state. The glass transition temperature was taken 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 was taken as the value of the crystallization peak temperature detected when the temperature was raised from 0 °C to 340 °C at a rate of 20 °C / min, held at 340 °C for 1 minute, and then cooled to 100 °C at a rate of 20 °C / min. The melting point was taken as the value of the melting peak temperature detected when the temperature was raised from 0 °C to 340 °C at a rate of 20 °C / min, held at 340 °C for 1 minute, cooled to 100 °C at a rate of 20 °C / min, held at 100 °C for 1 minute, and then raised to 340 °C again at a rate of 20 °C / min. The heat of fusion was taken as the amount of heat calculated from the melting peak.

[0198] The melting point (Tm), heat of fusion (ΔHm), and crystallization temperature (Tmc) of the polyarylene sulfide copolymer (D) in the fiber-reinforced polyarylene sulfide copolymer composite substrate were measured by a differential scanning calorimeter (DSC) in the same manner as above using about 10 to 25 mg of the composite substrate sample. The heat of fusion was calculated by converting the amount of heat calculated from the melting peak to the heat per unit weight of the polyarylene sulfide copolymer (D) excluding the reinforcing fibers in the fiber-reinforced polyarylene sulfide copolymer composite substrate. Apparatus: TA Instruments TA-Q200 Carrier gas: Nitrogen Sample purge flow rate: 50 mL / min.

[0199] [Measurement of Melt Complex Viscosity, Loss Elastic Modulus, and Storage Elastic Modulus] The measurement of the melt complex viscosity of the polyarylene sulfide copolymer before heat treatment, the measurement of the melt complex viscosity after heat treatment, and the measurement of the loss elastic modulus and storage elastic modulus for calculating the loss tangent were carried out using a rheometer under the following conditions. Apparatus: Physica MCR501 manufactured by Anton Paar Plate: Parallel (φ25 mm) Gap: 1.0 mm Angular frequency (ω): 6.28 rad / s Shearing stress (τ): 1,000 Pa Sample charged weight: approximately 0.7 g Measurement conditions: (a) η1 was measured by melting the sample at 340°C under a nitrogen stream at normal pressure and measuring the melt complex viscosity. (b) η2 was measured by heat-treating the sample in a rheometer at 340°C for 20 minutes under an air stream at normal pressure and then measuring the melt complex viscosity at 340°C. (c) η3 was measured by heat-treating the sample in a rheometer at 340°C for 60 minutes under an air stream at normal pressure and then measuring the melt complex viscosity at 340°C. (d) The loss elastic modulus and storage elastic modulus under a non-oxidizing atmosphere at normal pressure were measured by melting the sample at 340°C under a nitrogen stream at normal pressure. (e) The loss elastic modulus and storage elastic modulus for measuring the time until the loss tangent tanδ becomes 1 or less were measured while heat-treating the sample in a rheometer at 340°C under an air stream at normal pressure. The viscosity change rate Δη (times) was calculated from η1 and η2 by the following equation. Δη = η2 / η1 The loss tangent tanδ was calculated from the loss elastic modulus and storage elastic modulus by the following equation. tanδ = loss elastic modulus / storage elastic modulus.

[0200] [Measurement of Weight Loss Rate of Polyarylene Sulfide Copolymer during Heating] The weight loss rate of the polyarylene sulfide copolymer during heating was measured under the following conditions using a thermogravimetric analyzer. Apparatus: TGA7 manufactured by PerkinElmer Measurement atmosphere: Under a nitrogen stream Sample charged weight: approximately 5 mg Measurement conditions (a) Hold at a programmed temperature of 30°C for 1 minute (b) Increase the temperature from 30°C to 320°C. The heating rate at this time is 10°C / min. (c) Hold at a programmed temperature of 320°C for 60 minutes The weight reduction rate ΔW (%) was calculated from the sample weight (W1) at the time of reaching 100 °C and the sample weight (W2) after isothermal holding for 60 minutes after reaching 320 °C by the following formula. ΔW = (W1 - W2) / W1 × 100 (%).

[0201] [Molecular weight measurement] The number average molecular weight Mn and the weight average molecular weight Mw were calculated in terms of polystyrene by gel permeation chromatography (GPC), which is a type of size exclusion chromatography (SEC). When measuring the molecular weight of the polyarylene sulfide copolymer contained in the fiber-reinforced polyarylene sulfide copolymer composite substrate, the fiber-reinforced polyarylene sulfide copolymer composite substrate was immersed in 1-chloronaphthalene at 250 °C, shaken for 5 minutes, filtered through a membrane filter with a pore size of 1 μm, and the filtrate was collected and analyzed. Apparatus: Senshu Science SSC-7110 Column name: Shodex UT806M×2 Eluent: 1-chloronaphthalene Detector: Differential refractive index detector Column temperature: 210 °C Pre-thermostat temperature: 250 °C Pump thermostat temperature: 50 °C Detector temperature: 210 °C Flow rate: 1.0 mL / min Sample injection volume: 300 μL.

[0202] [Analysis of amino group content] The amount of amino groups in polyarylene sulfide (A) was measured by FT-IR (IR-810 type infrared spectrophotometer manufactured by JASCO Corporation) using an amorphous film prepared by quenching from the molten state by heating at 320 °C, and the absorption intensity at 3382 cm -1 derived from amino groups was compared with the absorption intensity at 1901 cm -1 derived from the benzene ring of the arylene sulfide unit to estimate.

[0203] [Measurement of weight reduction rate of polyarylene sulfide (A) during heating] The weight loss rate of polyarylene sulfide (A) upon heating was determined under the following conditions using a thermogravimetric analyzer. Apparatus: TGA7 manufactured by PerkinElmer Measurement atmosphere: Under a nitrogen stream Sample charged weight: Approximately 5 mg Measurement conditions (a) Hold at a programmed temperature of 30°C for 1 minute. (b) Increase the temperature from 30°C to 340°C. The heating rate during this period is 10°C / min. The weight loss rate was calculated from the weight at 320°C and the weight at 30°C using the following formula. Weight loss rate (%) = ((weight at 30°C (mg) - weight at 320°C (mg)) / weight at 30°C (mg)) × 100.

[0204] [Injection molding] Using a small injection molding machine HAAKE MiniJet Pro manufactured by Thermo Fisher Scientific K.K., ISO527-2-5A type test pieces were molded under the conditions of a resin temperature of 320°C and a mold temperature of 170°C.

[0205] [Tensile strength and elongation at break] The ISO527-2-5A type test pieces obtained by injection molding were subjected to a tensile test in accordance with ISO527-1, -2 (2012) using an AG-20kNx universal testing machine under the conditions of a tensile speed of 1 mm / min, an ambient temperature of 23°C, and a relative humidity of 50%, and the tensile strength and elongation at break were measured, and the average value of 5 measurements was obtained.

[0206] [Analysis of evolved gas upon heating (TPD-MS)] The amount of gas evolved in the presence of oxygen simulating atmospheric conditions was quantified under the following conditions by analysis of evolved gas upon heating (TPD-MS). Considering the component with m / z = 18 as water, the component with m / z = 44 as carbon dioxide, and the component with m / z = 64 as sulfur dioxide, the amount of gas evolved (weight %) = (weight of each gas evolved (g) / sample weight (g)) × 100, and the amount of gas evolved for each component was calculated. MS apparatus: GC / MS QP20 series manufactured by Shimadzu Corporation Heating conditions: After heating from room temperature to 340 °C at a heating rate of 50 °C / min, hold at 340 °C for 60 minutes. Atmosphere: Dry gas with 20% (volume ratio) oxygen mixed in an inert gas, flow rate 50 mL / min Measured mass number: m / z = 10 - 300 (m represents the mass number, z represents the valence of the ion) Standard substance: Carbon dioxide.

[0207] [Evaluation of impregnation state by void observation] The fiber-reinforced polyarylene sulfide copolymer composite substrate was cut, and the cross-section in the thickness direction of the fiber-reinforced polyarylene sulfide copolymer composite substrate was observed as follows. A sample in which the fiber-reinforced polyarylene sulfide copolymer composite substrate was embedded in an epoxy resin was prepared, and the sample was polished until the cross-section in the thickness direction of the fiber-reinforced polyarylene sulfide copolymer composite substrate could be observed well. Photographs were taken at a magnification of 400 times with a digital microscope (VHX-7000 manufactured by Keyence) microscope (CCD). By measuring the area ratios of the normal part and voids (void parts) of the photographed cross-section, the void ratio of the fiber-reinforced polyarylene sulfide copolymer composite substrate was calculated. Those with a void ratio of 3% or less were judged as ○, those exceeding 3% and 10% or less were judged as △, and those exceeding 10% were judged as ×.

[0208] [Reference Example 1] Into an autoclave equipped with a stirrer and a bottom plug valve, 10.33 kg (90.0 mol) of 47.9% sodium hydrosulfide, 4.10 kg (99.4 mol) of 97% sodium hydroxide, 20.82 kg (210 mol) of N-methyl-2-pyrrolidone (NMP), and 5.95 kg of ion-exchanged water were charged, and while passing nitrogen at normal pressure, it was gradually heated to 225 °C over about 3 hours. Heating was terminated and cooling was started when 11.44 kg of water and 0.025 kg of NMP were distilled off. Since the amount of hydrogen sulfide scattered at this time was 2.2 mol, the inorganic sulfidizing agent in the system after this step was 87.8 mol.

[0209] After that, it was cooled to 200 °C, 13.63 kg (92.7 mol) of p-dichlorobenzene (p-DCB), 1.24 kg (9.78 mol) of 4-aminothiophenol (4-ATP), and 13.88 kg (140 mol) of NMP were added. Then the reaction vessel was sealed under nitrogen gas and heated to 260 °C at a rate of 0.6 °C / min with stirring, and reacted at 260 °C for 120 minutes.

[0210] After the reaction was completed, the bottom plug valve of the autoclave was immediately opened, and the content was flushed into a device with a stirrer and dried for 1.5 hours in the device with a stirrer at 230 °C, and a solid containing PPS and salts was recovered.

[0211] The obtained recovered product and ion-exchanged water were put into an autoclave with a stirrer, washed at 75 °C for 15 minutes, and then filtered through a filter three times to obtain a cake. The obtained cake and 30 liters of ion-exchanged water were put into an autoclave with a stirrer. After replacing the inside of the autoclave with nitrogen, the temperature was raised to 195 °C. Then, the autoclave was cooled, and the content was filtered through a filter to obtain a cake. The obtained cake was dried at 120 °C under a nitrogen stream.

[0212] 5 kg of the obtained dried cake and 50 kg of N-methyl-2-pyrrolidone (NMP) were put into a container with a stirrer, stirred for 30 minutes, and then filtered through a filter to obtain a cake. The obtained cake was washed and filtered with 50 liters of ion-exchanged water for 15 minutes three times, and then dried at 120 °C for 4 hours under a nitrogen stream to obtain dried PPS.

[0213] The obtained PPS had an amino group content of 650 μmol / g, a number average molecular weight of 3,100, a weight average molecular weight of 6,200, a dispersity of 2.0, and a weight loss rate of 2.3% when heated at a heating rate of 10 °C / min from 30 °C to 320 °C.

[0214] [Reference Example 2] After the reaction was completed in the same manner as in Reference Example 1, the contents were cooled to 250°C at a rate of 1°C / min, and then 8.8 kg of water was added while cooling to 217°C at a rate of 0.6°C / min. After cooling to 105°C at a rate of 1°C / min, it was cooled to near room temperature.

[0215] The contents were taken out, diluted with 4 times the amount of ion-exchanged water of the obtained contents, and the solvent and solids were separated by filtration through a sieve (80 mesh). The obtained solids and ion-exchanged water were put into an autoclave equipped with a stirrer, washed at 75°C for 15 minutes, and then the operation of filtering with a filter was performed 3 times to obtain a cake. The obtained cake was dried at 120°C under a nitrogen stream. 5 kg of the obtained dried cake and 50 kg of N-methyl-2-pyrrolidone (NMP) were put into a container equipped with a stirrer, stirred for 30 minutes, and then filtered through a filter to obtain a cake. The obtained cake was washed with 50 liters of ion-exchanged water for 15 minutes and filtered 3 times, and then dried at 120°C for 4 hours under a nitrogen stream to obtain dried PPS.

[0216] The obtained PPS had an amino group content of 535 μmol / g, a number average molecular weight of 3,100, a weight average molecular weight of 7,400, a dispersity of 2.4, and a weight loss rate of 1.5% when heated at a heating rate of 10°C / min from 30°C to 320°C.

[0217] [Example 1] The PPS obtained in Reference Example 1 and pyromellitic dianhydride were mixed such that the ratio of the amount of acid anhydride groups in pyromellitic dianhydride to the amount of amino groups in PPS was 1.1. As a phenolic antioxidant, 3,9-bis{2-[3-(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy]-1,1-dimethylethyl}-2,4,8,10-tetraoxaspiro[5.5]undecane (ADEKA's "ADK STAB" (registered trademark) AO-80) was 0.5 parts by weight with respect to 100 parts by weight of PPS (which can be converted to 0.47 parts by weight with respect to 100 parts by weight of the resulting PPS copolymer). As a phosphorus-based antioxidant, 3,9-bis(2,6-di-t-butyl-4-methylphenoxy)2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane (ADEKA's "ADK STAB" (registered trademark) PEP-36) was 0.5 parts by weight with respect to 100 parts by weight of PPS (which can be converted to 0.47 parts by weight with respect to 100 parts by weight of the resulting PPS copolymer).

[0218] Using Japan Steel Works, Ltd.'s TEX30α (L / D = 45.5), with a setting where an atmospheric vent zone was provided at positions of 0.33 L (position of 15D) and 0.84 L (position of 38D), the heating temperature was 300 °C, the discharge rate was 7 kg / h, and the screw rotation speed was 200 rpm, the above mixture was melt-kneaded.

[0219] The weight-average molecular weight of the obtained melt-extrudate was 37,900.

[0220] Using Japan Steel Works, Ltd.'s TEX30α (L / D = 45.5), with a setting where a vacuum vent zone was provided at a position of 0.84 L (position of 38D), the heating temperature was 360 °C, the discharge rate was 7 kg / h, and the screw rotation speed was 100 rpm, the above melt-extrudate was melt-kneaded. The pressure value was 26 kPa.

[0221] From the FT-IR spectrum, it was confirmed that the obtained PPS copolymer contained phenylene sulfide units as structural units and that imide groups were introduced. As a result of DSC measurement, the glass transition temperature was 111 °C, the crystallization temperature was 199 °C, the melting point was 261 °C, and the heat of fusion was 26 J / g. As a result of GPC measurement, Mw was 48,400, Mn was 11,500, and Mw / Mn was 4.2. η1 was 70 Pa·s, η2 was 580 Pa·s, the viscosity change rate Δη was 8.3 times, η3 was 5,160 Pa·s, the loss tangent tanδ was 23.8, and the time until the loss tangent tanδ became 1 or less was 20 minutes. The weight loss rate ΔW was 0.28%, the water quantified by heating gas analysis was 0.47% by weight, carbon dioxide was 0.36% by weight, and sulfur dioxide was 0.29% by weight. The obtained product was subjected to injection molding, and the resulting molded product was subjected to a tensile test. As a result, the tensile strength was 74 MPa and the tensile elongation at break was 5.5%. The results are summarized in Table 1.

[0222] [Example 2] Using the PPS obtained in Reference Example 2, PPS, pyromellitic dianhydride, AO-80, and PEP-36 were mixed in the same manner as in Example 1, except that the ratio of the amount of acid anhydride groups in pyromellitic dianhydride to the amount of amino groups in PPS was adjusted to 1.3.

[0223] Using a Nippon Steel Works TEX30α (L / D = 45.5), with the setting of providing an atmospheric vent zone at positions of 0.33 L (position of 15D) and 0.84 L (position of 38D), the heating temperature was 300 °C, the discharge rate was 7 kg / h, and the screw rotation speed was 200 rpm, and the above mixture was melt-kneaded.

[0224] The weight average molecular weight of the obtained melt extrudate was 26,700.

[0225] Using a Nippon Steel Works TEX30α (L / D = 45.5), with the setting of providing a vacuum vent zone at the position of 0.84 L (position of 38D), the heating temperature was 360 °C, the discharge rate was 7 kg / h, and the screw rotation speed was 100 rpm, and the above melt extrudate was melt-kneaded twice. The pressure value was 41 kPa.

[0226] From the FT-IR spectrum, it was confirmed that the obtained PPS copolymer contained phenylene sulfide units as structural units and that imide groups were introduced. As a result of DSC measurement, the glass transition temperature was 112 °C, the crystallization temperature was 202 °C, the melting point was 264 °C, and the heat of fusion was 34 J / g. As a result of GPC measurement, Mw was 39,100, Mn was 10,400, and Mw / Mn was 3.8. η1 was 40 Pa·s, η2 was 183 Pa·s, the viscosity change rate Δη was 4.5 times, η3 was 7,180 Pa·s, the loss tangent tanδ was 63.1, and the time until the loss tangent tanδ became 1 or less was 33 minutes. The weight loss rate ΔW was 0.18%. The results were summarized in Table 1.

[0227] [Comparative Example 1] PPS, pyromellitic dianhydride, AO-80, and PEP-36 were mixed in the same manner as in Example 1, except that the ratio of the amount of acid anhydride groups in pyromellitic dianhydride to the amount of amino groups in PPS was adjusted to 1.2.

[0228] Using Nippon Steel Works' TEX30α (L / D = 45.5), with the setting of providing an atmospheric vent zone at the position of 0.84 L (position of 38D), the heating temperature was 300 °C, the discharge rate was 5 kg / h, the screw rotation speed was 200 rpm, and the above mixture was melt-kneaded.

[0229] The weight average molecular weight of the obtained melt extrudate was 25,800.

[0230] Using Nippon Steel Works' TEX30α (L / D = 45.5), with the setting of not providing a vent zone, the heating temperature was 380 °C, the discharge rate was 5 kg / h, the screw rotation speed was 100 rpm, and the above melt extrudate was melt-kneaded twice.

[0231] From the FT-IR spectrum, it was confirmed that the obtained PPS copolymer contained phenylene sulfide units as structural units and imide groups were introduced. As a result of DSC measurement, the glass transition temperature was 114 °C, the crystallization temperature was 206 °C, the melting point was 263 °C, and the heat of fusion was 32 J / g. As a result of GPC measurement, Mw was 45,100, Mn was 13,800, and Mw / Mn was 3.3. η1 was 40 Pa·s, η2 was 2,170 Pa·s, the viscosity change rate Δη was 54.4 times, η3 was 10,900 Pa·s, the loss tangent tanδ was 51.2, and the time until the loss tangent tanδ became 1 or less was 12 minutes. The weight loss rate ΔW was 0.63%. The obtained molded product was subjected to injection molding and then subjected to a tensile test. As a result, the tensile strength was 37 MPa and the tensile elongation at break was 3.2%. The results are summarized in Table 1.

[0232] [Comparative Example 2] The PPS obtained in Reference Example 1 and pyromellitic dianhydride were mixed so that the ratio of the amount of acid anhydride groups in pyromellitic dianhydride to the amount of amino groups in PPS was 1.25.

[0233] Using TEX30α (L / D = 45.5) manufactured by Japan Steel Works, with the vacuum vent zone set at a position of 0.84 L (position of 38D), the heating temperature was 300 °C, the discharge rate was 5 kg / h, the screw rotation speed was 200 rpm, and the above mixture was melt-kneaded. The pressure value was 51 kPa.

[0234] The weight-average molecular weight of the obtained melt extrudate was 26,400.

[0235] Using TEX30α (L / D = 45.5) manufactured by Japan Steel Works, with the vacuum vent zone set at a position of 0.84 L (position of 38D), the heating temperature was 380 °C, the discharge rate was 5 kg / h, the screw rotation speed was 100 rpm, and the above melt extrudate was melt-kneaded. The pressure value was 11 kPa.

[0236] From the FT-IR spectrum, it was confirmed that the obtained PPS copolymer contained phenylene sulfide units as structural units and that imide groups were introduced. As a result of DSC measurement, the glass transition temperature was 113°C, the crystallization temperature was 172°C, the melting point was 259°C, and the heat of fusion was 21 J / g. As a result of GPC measurement, Mw was 76,700, Mn was 10,300, and Mw / Mn was 7.5. η1 was 400 Pa·s, η2 was 12,200 Pa·s, the viscosity change rate Δη was 30.5 times, η3 was 27,700 Pa·s, the loss tangent tanδ was 3.0, and the time until the loss tangent tanδ became 1 or less was less than 1 minute. The weight loss rate ΔW was 0.22%, the water quantified by heating gas analysis was 0.70 wt%, carbon dioxide was 0.87 wt%, and sulfur dioxide was 0.69 wt%. The obtained molded product was subjected to a tensile test after being injection molded, and as a result, the tensile strength was 78 MPa and the tensile elongation at break was 5.8%. The results are summarized in Table 1.

[0237]

Table 1

[0238] As shown in Example 1 and Example 2, the polyarylene sulfide copolymer of the present invention has a high glass transition temperature, excellent heat resistance, a small Δη, a low η3, excellent stability and melt molding processability, and a small ΔW, so that contamination and voids in the molded product are less likely to occur, and it is clear that it is a high-quality polyarylene sulfide copolymer with excellent productivity and mechanical properties.

[0239] When comparing Example 1, Example 2 with Comparative Example 2, it can be seen that in Example 1 and Example 2, by containing an antioxidant, η1, η2, and η3 are low, Δη is small, and the melt molding processability and stability are excellent. Also, Tmc is high, ΔHm is large, Mw / Mn is small, and it is considered that side reactions considered to be cross-linking reactions are suppressed. Furthermore, in Example 1, although η1 contributing to mechanical properties and the weight average molecular weight are lower than those in Comparative Example 2, it shows a tensile strength and a tensile elongation at break equivalent to those in Comparative Example 2. It is presumed that this is because side reactions considered to be cross-linking reactions are suppressed compared to Comparative Example 2, and it can be seen that it is a polyarylene sulfide copolymer with excellent mechanical properties and high quality.

[0240] When Example 1 is compared with Comparative Example 1, it can be seen that in Example 1, η1 and the weight average molecular weight that contribute to mechanical properties show higher values than those in Comparative Example 1, while η2 and η3 are low, Δη is very small, and the melt molding processability and stability are excellent. In Example 1, although the heating in the first stage (corresponding to Step 1) is at the same temperature as in Comparative Example 1 and the heating in the second stage (corresponding to Step 2) is at a lower temperature than in Comparative Example 1, the results of high η1 and weight average molecular weight are due to the effects of the atmospheric vent zone and further the vacuum vent zone, where water, the main volatile component, is efficiently removed, and the reaction between the functional groups derived from polyarylene sulfide (A), which is a desirable reaction, and the functional groups derived from compound (B) proceeds easily, and side reactions are easily suppressed. It is presumed that this is the reason. Also, although the type and amount of the same antioxidant are used, the fact that η2 and η3 are lower and Δη is very small in Example 1 is considered to be because, in addition to the effects of the above-mentioned atmospheric vent zone and vacuum vent zone, by lowering the heating temperature in the second stage, side reactions can be further suppressed, and the decomposition, deactivation, and volatilization of the antioxidant can also be suppressed. Further, the polyarylene sulfide copolymer of Example 1 is a polyarylene sulfide copolymer excellent in productivity and mechanical properties in that ΔW is small and contamination and voids in the molded product are less likely to occur. When comparing the mechanical properties of Example 1 and Comparative Example 1, although it is considered to be the effect of less ΔW, it can be seen that Example 1 is a polyarylene sulfide copolymer excellent in tensile strength and elongation at break. It is considered to be due to the removal of impurities, by-products, and volatile components contained in the polyarylene sulfide copolymer by the atmospheric vent zone and vacuum vent zone, and the suppression of side reactions by lowering the heating temperature in the second stage, and the suppression of the decomposition of the polyarylene sulfide copolymer and antioxidant.

[0241] Comparing Example 2 with Comparative Example 1, it can be seen that in Example 2, although η1 is equivalent to that of Comparative Example 1, η2 and η3 are low, and Δη is very small, indicating excellent melt molding processability and stability. In Example 2, the heating in the first stage (corresponding to Step 1) is at the same temperature as in Comparative Example 1, and despite the heating in the second stage (corresponding to Step 2) being at a lower temperature than in Comparative Example 1, the fact that η1 is equivalent is presumably because, due to the effects of the air-release vent zone and further the vacuum vent zone, water, which is the main volatile component, is efficiently removed, facilitating the progress of the reaction between the functional groups derived from polyarylene sulfide (A), which is a desirable reaction, and the functional groups derived from compound (B), and making it easier to suppress side reactions. The reason that η1 and the weight average molecular weight in Example 2 are lower than those in Example 1 is considered to be mainly because the ratio of the amount of acid anhydride groups in pyromellitic dianhydride to the amount of amino groups in PPS is set higher in Example 2. Despite the same type and amount of antioxidant, the fact that η2 and η3 are lower and Δη is very small in Example 2 compared to Comparative Example 1 is presumably because, in addition to the effects of the above-mentioned air-release vent zone and vacuum vent zone, lowering the heating temperature in the second stage enables further suppression of side reactions and also suppression of the decomposition, deactivation, and volatilization of the antioxidant. Further, the polyarylene sulfide copolymer of Example 2 is a polyarylene sulfide copolymer that is excellent in productivity and mechanical properties in that ΔW is small and it is less likely to cause contamination and voids in the molded product.

[0242] [Example 3] Sixteen bobbins wound with carbon fiber bundles (T700S-12K manufactured by Toray Industries, Inc.) were prepared, and carbon fiber bundles were continuously fed out from each bobbin through a thread guide. The continuously fed carbon fiber bundles were impregnated with the PPS copolymer of Example 1 quantitatively supplied from a filled feeder in an impregnation die. The carbon fibers impregnated with the PPS copolymer of Example 1 in the impregnation die were continuously pulled out from the nozzle of the impregnation die at a pulling speed of 1 m / min using a take-up roll. The temperature at the time of pulling out the carbon fibers was 340 °C. The pulled-out carbon fiber bundles passed through a cooling roll, the PPS copolymer was cooled and solidified, and then wound by a winder. By further pressing the carbon fiber bundle containing the PPS copolymer at 300 °C for 30 minutes, a fiber-reinforced PPS copolymer composite base material with a thickness of 0.2 mm and a volume content of reinforcing fibers of 52% was obtained. The evaluation results of the obtained fiber-reinforced PPS copolymer composite base material were summarized in Table 2. For the measurement of the molecular weight of the PPS copolymer (D), when the fiber-reinforced PPS copolymer composite base material was immersed in 1-chloronaphthalene at 250 °C, shaken for 5 minutes, and then filtered through a membrane filter with a pore size of 1 μm, no insoluble resin component was observed.

[0243] [Comparative Example 3] The same conditions as in Example 3 were carried out except that the PPS copolymer obtained in Comparative Example 1 was used, and a fiber-reinforced PPS copolymer composite base material with a thickness of 0.2 mm and a volume content of reinforcing fibers of 47% was obtained. The evaluation results of the obtained fiber-reinforced PPS copolymer composite base material were summarized in Table 2. For the measurement of the molecular weight of the PPS copolymer (D), when the fiber-reinforced PPS copolymer composite base material was immersed in 1-chloronaphthalene at 250 °C, shaken for 5 minutes, and then filtered through a membrane filter with a pore size of 1 μm, no insoluble resin component was observed.

[0244] [Comparative Example 4] Using the PPS copolymer obtained in Comparative Example 2, 3,9-bis{2-[3-(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy]-1,1-dimethylethyl}-2,4,8,10-tetraoxaspiro[5.5]undecane ("ADEKA STAB" (registered trademark) AO80 manufactured by ADEKA) as a phenolic antioxidant was added in an amount of 0.1 part by weight based on 100 parts by weight of the PPS copolymer, and 3,9-bis(2,6-di-t-butyl-4-methylphenoxy)2,4,8,10-tetraoxa-3,9-diphosphapiro[5.5]undecane ("ADEKA STAB" (registered trademark) PEP36 manufactured by ADEKA) as a phosphorus-based antioxidant was added in an amount of 0.1 part by weight based on 100 parts by weight of the PPS copolymer. The experiment was carried out under the same conditions as in Example 1, and a fiber-reinforced PPS copolymer composite base material with a thickness of 0.2 mm and a volume content of reinforcing fibers of 47% was obtained. The evaluation results of the obtained fiber-reinforced PPS copolymer composite base material are summarized in Table 2. For the measurement of the molecular weight of the PPS copolymer (D), when the fiber-reinforced PPS copolymer composite base material was immersed in 1-chloronaphthalene at 250°C, shaken for 5 minutes, and then filtered through a membrane filter with a pore size of 1 μm, a partially insoluble resin component remained on the filter.

[0245]

Table 2

[0246] As shown in Example 3, in the present invention, a fiber-reinforced polyarylene sulfide copolymer composite base material impregnated with a polyarylene sulfide copolymer could be obtained.

[0247] When Example 3 is compared with Comparative Example 4, in Example 3, the crystallization temperature is high, the dispersity represented by the weight average molecular weight / number average molecular weight is small, and a fiber-reinforced PPS copolymer composite base material with a good impregnation state is obtained. It is presumed that the excellent crystallization characteristics and small dispersity are due to the contribution of the antioxidant. Also, it can be seen that by impregnating a PPS copolymer excellent in viscosity stability during heating, the impregnation state becomes good. In Comparative Example 4, since a PPS copolymer with a high η1 and a large Δη was impregnated, the impregnation state into the carbon fiber was insufficient. Further, in Example 3, unlike Comparative Example 4, since there is no insoluble resin component in 1-chloronaphthalene at 250 °C, it is considered that the cross-linked structure due to side reactions and significant increase in molecular weight can be suppressed.

[0248] Even in Comparative Example 3, a fiber-reinforced PPS copolymer composite base material with a high crystallization temperature, a small dispersity represented by the weight average molecular weight / number average molecular weight, and a good impregnation state is obtained compared to Comparative Example 4. However, when Example 3 is compared with Comparative Example 3, a fiber-reinforced PPS copolymer composite base material with a higher crystallization temperature is obtained in Example 3. Further, when comparing the crystallization temperatures before and after manufacturing the fiber-reinforced PPS copolymer composite base material, it can be seen that the change in the crystallization temperature from Example 1 to Example 3 is smaller than the change in the crystallization temperature from Comparative Example 1 to Comparative Example 3. It is considered that impurities, by-products, and volatile components contained in the polyarylene sulfide copolymer were removed by the air-release vent zone and the vacuum vent zone, and side reactions were suppressed by lowering the temperature of the second-stage heating, and decomposition of the polyarylene sulfide copolymer and the antioxidant was also suppressed. However, the PPS copolymer of the present invention is excellent in viscosity stability during heating and also excellent in thermal property stability. By using the PPS copolymer of the present invention, a fiber-reinforced PPS copolymer composite base material with a stable and high crystallization temperature, a high crystallization rate, and high productivity during melt molding can be obtained. Furthermore, it is considered that a molded body manufactured using this fiber-reinforced PPS composite base material is likely to be sufficiently crystallized and tends to have excellent mechanical properties and chemical resistance.

Claims

1. A polyarylene sulfide copolymer having a glass transition point of 95° C. or higher and 190° C. or lower, containing an antioxidant, a viscosity change rate Δη represented by the following formula (1) being more than 1 time and not more than 10 times, and a weight reduction rate ΔW represented by the following formula (2) being 0.5% or lower. Δη=η2 / η1...(1) (Here, Δη is the viscosity change rate (times), η1 is the melt complex viscosity measured in a non-oxidizing atmosphere at 340° C., angular frequency 6.28 rad / s, shear stress 1,000 Pa, and normal pressure before heat treatment, and η2 is the melt complex viscosity measured in a non-oxidizing atmosphere at 340° C., angular frequency 6.28 rad / s, shear stress 1,000 Pa, and normal pressure after heat treatment at 340° C. for 20 minutes in the air at normal pressure.) ΔW=(W1-W2) / W1×100...(2) (Here, ΔW is the weight loss rate (%), W1 is the sample weight at 100° C. when the temperature is increased from 30° C. to 320° C. at a rate of 10° C. / min in a non-oxidizing atmosphere at normal pressure, and W2 is the sample weight after the sample is kept isothermal for 60 minutes after reaching 320° C.)

2. The polyarylene sulfide copolymer according to claim 1, which has a melt complex viscosity η3 of 10,000 Pa·s or less measured at 340°C, an angular frequency of 6.28 rad / s and a shear stress of 1,000 Pa after heat treatment at 340°C for 60 minutes under atmospheric pressure.

3. 2. The polyarylene sulfide copolymer according to claim 1, which has arylene sulfide units having a number average molecular weight Mn of 1,000 or more and 10,000 or less.

4. 2. The polyarylene sulfide copolymer according to claim 1, which has at least one structure selected from the following formulas (a) to (s) as a structural unit: 【Chemistry 1】 (R, R １ , and R ２ is a substituent selected from hydrogen, an alkyl group having 1 to 12 carbon atoms, an arylene group having 6 to 24 carbon atoms, and a halogen group; R, R １ , and R ２ may be the same or different.)

5. 2. The polyarylene sulfide copolymer according to claim 1, having a melting point of 300° C. or lower.

6. 2. The polyarylene sulfide copolymer according to claim 1, having a weight average molecular weight Mw of 10,000 or more and 200,000 or less.

7. 2. The polyarylene sulfide copolymer according to claim 1, wherein the polydispersity, expressed as weight average molecular weight Mw / number average molecular weight Mn, is 7.0 or less.

8. A fiber-reinforced polyarylene sulfide copolymer composite substrate obtained by impregnating a reinforcing fiber substrate having continuous reinforcing fibers or discontinuous reinforcing fibers dispersed therein with the polyarylene sulfide copolymer according to any one of claims 1 to 7.

9. A method for producing a polyarylene sulfide copolymer, comprising heating polyarylene sulfide (A) (hereinafter sometimes abbreviated as polyarylene sulfide (A)), which contains amino groups in the range of 400 μmol / g or more and 5,000 μmol / g or less and has a weight loss rate of 5 wt % or less when heated from 30° C. to 320° C. at a temperature increase rate of 10° C. / min, and at least one compound (B) (hereinafter sometimes abbreviated as compound (B)) selected from the following formulae (a') to (u'), in the presence of an antioxidant, characterized in that at least step 1 is carried out: Step 1: A step of melt-extruding a polyarylene sulfide (A), a compound (B), and an antioxidant using an extruder having a main hopper and configured in this order from the main hopper toward downstream, a first kneading zone, a vent zone, and a second kneading zone, with the vent zone being provided at a position within 0.5 L from the upstream end of the screw. (where L is the length of the extruder screw). 【Chemistry 2】 (X is two carboxyl groups bonded to two adjacent carbon atoms, or an acid anhydride group derived from the two carboxyl groups; R, R １ , and R ２ is a substituent selected from hydrogen, an alkyl group having 1 to 12 carbon atoms, an arylene group having 6 to 24 carbon atoms, and a halogen group; R, R １ , and R ２ may be the same or different. In addition, the aromatic ring of each compound may be di- or tri-substituted, and the multiple substituents X substituted on one aromatic ring may be the same or different.

10. The method for producing a polyarylene sulfide copolymer according to claim 9, wherein the vent zone in step 1 is an atmospheric vent zone.

11. The method for producing a polyarylene sulfide copolymer according to claim 9, wherein the heating temperature in step 1 is 320° C. or lower.

12. 10. The method for producing a polyarylene sulfide copolymer according to claim 9, wherein after step 1, a step 2 is carried out in which the molten extrudate obtained in step 1 is further molten extruded in an extruder having a vacuum vent.

13. The method for producing a polyarylene sulfide copolymer according to claim 12, wherein the heating temperature in the step 2 is higher than the heating temperature in the step 1 and is 370°C or lower.

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