Method for manufacturing polyamide resin, and resin composition

Abstract

The present invention provides a novel method for manufacturing a polyamide resin obtained by polycondensation of a diamine represented by formula (1) and an aliphatic dicarboxylic acid. The present invention also provides a resin composition in which a polyamide resin is used. The method for manufacturing a polyamide resin includes polycondensing a diamine and a dicarboxylic acid in the presence of water to obtain a primary polycondensate, and increasing the degree of polymerization of the primary polycondensate, more than 30 mol% of the diamine being a diamine represented by formula (1), and 20 mol% or more of the dicarboxylic acid being an aromatic dicarboxylic acid. In formula (1), R1-R8 each independently represent a hydrogen atom or an aliphatic group having 1-5 carbon atoms. X1 and X2 each independently is 1 or 2.

Description

Method for producing polyamide resin and resin composition

[0001] The present invention relates to a method for producing a polyamide resin and a resin composition.

[0002] Polyamide resins are widely used as various industrial materials due to their excellent processability, durability, heat resistance, gas barrier properties, chemical resistance, etc. Aliphatic polyamide resins, such as polyamide 6 and polyamide 66, have long been used as such polyamide resins. Furthermore, aromatic polyamide resins, which use aromatic dicarboxylic acids and / or aromatic diamines as raw materials for the polyamide resin, are also increasingly being used. Such aromatic polyamide resins are described, for example, in Patent Documents 1 and 2.

[0003] JP-A No. 62-054725 JP-A No. 08-003312

[0004] The present inventors have developed a polyamide resin obtained by polycondensation of a diamine represented by formula (1) with a dicarboxylic acid. There is a need for a new method for producing such a polyamide resin. (In formula (1), R １ ~R ８ each independently represents a hydrogen atom or an aliphatic group having 1 to 5 carbon atoms. X1 and X2 each independently represent 1 or 2.

[0005] The present invention aims to solve the above problems by providing a novel method for producing a polyamide resin obtained by polycondensation of a diamine represented by formula (1) with a dicarboxylic acid, and also aims to disclose a resin composition using the polyamide resin obtained by the above production method.

[0006] In light of the above-mentioned problems, the present inventors have conducted research and found that an excellent polyamide resin can be obtained by polycondensing a diamine, including a diamine represented by formula (1), with a dicarboxylic acid in the presence of water to obtain a primary polycondensate, and then increasing the degree of polymerization of the primary polycondensate. Specifically, the above-mentioned problems have been solved by the following means. <1> A method for producing a polyamide resin, comprising polycondensing a diamine with a dicarboxylic acid in the presence of water to obtain a primary polycondensate, and then increasing the degree of polymerization of the primary polycondensate, wherein more than 30 mol % of the diamine is a diamine represented by formula (1), and 20 mol % or more of the dicarboxylic acid is an aromatic dicarboxylic acid. Formula (1) (In formula (1), R １ ~R ８each independently represent a hydrogen atom or an aliphatic group having 1 to 5 carbon atoms. X1 and X2 each independently represent 1 or 2.) <2> The production method according to <1>, wherein stirring in the polycondensation is performed using a stirring blade, and a sealing liquid is placed between the shaft of the stirring blade and the top plate of the reaction vessel to seal. <3> The production method according to <1> or <2>, wherein the diamine and the dicarboxylic acid are added simultaneously to a polycondensation reaction system. <4> The production method according to any one of <1> to <3>, wherein the amount of water added to the polycondensation reaction system is 28 to 80 mass% based on the total amount of substances present in the polycondensation reaction system. <5> The production method according to any one of <1> to <4>, wherein a portion of the water is removed from the polycondensation reaction system and the polycondensation is further advanced. <6> The production method according to any one of <1> to <5>, wherein the primary polycondensate is polymerized to a high degree by solid-state polymerization. <7> The method according to any one of <1> to <6>, wherein the polyamide resin is composed of diamine-derived structural units and dicarboxylic acid-derived structural units, wherein 50 mol % or more of the diamine-derived structural units are p-benzenediethaneamine-derived structural units and 65 mol % or more of the dicarboxylic acid-derived structural units are aromatic dicarboxylic acid-derived structural units. <8> The method according to <7>, wherein 65 to 97 mol % of the dicarboxylic acid-derived structural units are aromatic dicarboxylic acid-derived structural units and 3 to 35 mol % are alicyclic dicarboxylic acid-derived structural units. <9> The method according to any one of <1> to <6>, wherein the polyamide resin is composed of diamine-derived structural units and dicarboxylic acid-derived structural units, 50 mol % or more of the diamine-derived structural units being structural units derived from p-benzenediethaneamine, 20 mol % or more but less than 95 mol % of the dicarboxylic acid structural units being structural units derived from aromatic dicarboxylic acid, and more than 5 mol % but not more than 80 mol % being structural units derived from an α,ω-linear aliphatic dicarboxylic acid having 4 to 15 carbon atoms. <10> The method according to <9>, wherein more than 5 mol % but not more than 80 mol % of the dicarboxylic acid structural units are structural units derived from a dicarboxylic acid selected from adipic acid and sebacic acid.<11> The method according to <9>, wherein 40 to 90 mol % of the dicarboxylic acid-derived structural units are structural units derived from aromatic dicarboxylic acids, and 10 to 60 mol % are structural units derived from α,ω-linear aliphatic dicarboxylic acids having 4 to 15 carbon atoms. <12> The method according to any one of <1> to <6>, wherein the polyamide resin is composed of diamine-derived structural units and dicarboxylic acid-derived structural units, wherein 70 to 97 mol % of the diamine-derived structural units are derived from p-benzenediethaneamine, and 3 to 30 mol % are derived from a diamine represented by formula (1-1), and 50 mol % or more of the dicarboxylic acid-derived structural units are derived from aromatic dicarboxylic acids. Formula (1-1). (In formula (1-1), R １１ ~R １８ each independently represents a hydrogen atom or an aliphatic group having 1 to 5 carbon atoms; R １１ ~R １４ and at least one of R １５ ~R １８ At least one of the above is an aliphatic group having 1 to 5 carbon atoms.) <13> The polyamide resin is composed of diamine-derived structural units and dicarboxylic acid-derived structural units, more than 30 mol % of the diamine-derived structural units are derived from a diamine represented by formula (1-1), and more than 30 mol % of the dicarboxylic acid-derived structural units are derived from an aromatic dicarboxylic acid. Formula (1-1) (In formula (1-1), R １１ ~R １８ each independently represents a hydrogen atom or an aliphatic group having 1 to 5 carbon atoms; R １１ ~R １４ and at least one of R １５ ~R １８ At least one of the groups is an aliphatic group having 1 to 5 carbon atoms.) <14> The polyamide resin according to any one of <1> to <6>, wherein the polyamide resin contains structural units derived from diamines and structural units derived from dicarboxylic acids, and 50 mol % or more of the structural units derived from diamines are derived from a compound represented by formula (1-2), and more than 50 mol % of the structural units of the dicarboxylic acids are derived from an aromatic dicarboxylic acid. Formula (1-2) (In formula (1-2), R ２１~R ２８ each independently represents a hydrogen atom or an aliphatic group having 1 to 5 carbon atoms.) <15> A resin composition comprising a polyamide resin containing diamine-derived structural units and dicarboxylic acid-derived structural units, wherein more than 30 mol % of the diamine-derived structural units are diamine-derived structural units represented by formula (1), and 20 mol % or more of the dicarboxylic acid-derived structural units are aromatic dicarboxylic acid-derived structural units, and a reinforcing material. Formula (1) (In formula (1), R １ ~R ８ each independently represents a hydrogen atom or an aliphatic group having 1 to 5 carbon atoms. X1 and X2 each independently represent 1 or 2.

[0007] The present invention provides a novel method for producing a polyamide resin obtained by polycondensation of a diamine represented by formula (1) with a dicarboxylic acid, and also provides a resin composition using the polyamide resin obtained by the above-mentioned method.

[0008] Hereinafter, a mode for carrying out the present invention (hereinafter simply referred to as "the present embodiment") will be described in detail. Note that the following present embodiment is an example for explaining the present invention, and the present invention is not limited to this embodiment. Note that in this specification, "to" is used to mean that the numerical values ​​written before and after it are included as lower and upper limits. In this specification, various physical property values ​​and characteristic values ​​are at 23°C unless otherwise specified. In this specification, the term "process" includes not only an independent process, but also a process that cannot be clearly distinguished from other processes, as long as the intended effect of the process is achieved. If the measurement methods, etc. described in the standards shown in this specification vary depending on the fiscal year, they will be based on the standards as of January 1, 2021, unless otherwise specified.

[0009] Unless otherwise specified, the pressure in this specification is an absolute pressure (0 MPa in a vacuum).

[0010] The method for producing a polyamide resin of this embodiment includes polycondensing a diamine and a dicarboxylic acid in the presence of water to obtain a primary polycondensate, and increasing the degree of polymerization of the primary polycondensate, and is characterized in that more than 30 mol % (preferably more than 57 mol %) of the diamine is a diamine represented by formula (1), and 20 mol % or more of the dicarboxylic acid is an aromatic dicarboxylic acid. (In formula (1), R １ ~R ８ each independently represents a hydrogen atom or an aliphatic group having 1 to 5 carbon atoms. X1 and X2 each independently represent 1 or 2.) A novel method can be used to produce a polyamide resin obtained by polycondensation of a diamine represented by formula (1) with an aliphatic dicarboxylic acid. In particular, this method enables mass production of the polyamide resin. Furthermore, a relatively high molecular weight polyamide resin can be obtained.

[0011] The method for producing a polyamide resin according to the present embodiment includes polycondensing a diamine and a dicarboxylic acid in the presence of water to obtain a primary polycondensate. The water used here does not refer to condensed water produced by the polycondensation of a diamine and a dicarboxylic acid, but rather refers to water added to a polycondensation reaction system in which the polycondensation reaction of a diamine and a dicarboxylic acid is initiated in the presence of water.

[0012] In this specification, in the process of polycondensing a diamine and a dicarboxylic acid in the presence of water to obtain a primary polycondensate (polycondensation reaction process), the process before the water-removal process is sometimes referred to as an early polycondensation process, and the process after the water-removal process until the primary polycondensate is obtained is sometimes referred to as a late polycondensation process.

[0013] The diamines used as raw materials for the polyamide resin in the production method of this embodiment are diamines represented by formula (1) in an amount of more than 30 mol %. The preferred composition of the diamines is appropriately selected depending on the composition of the polyamide resin, which will be described in detail later. Furthermore, 20 mol % or more of the dicarboxylic acids are aromatic dicarboxylic acids. The preferred composition of the dicarboxylic acids is also appropriately selected depending on the composition of the polyamide resin, which will be described in detail later.

[0014] In the production method of this embodiment, it is preferable that the diamine and the dicarboxylic acid are added to the polycondensation reaction system simultaneously. The simultaneous addition includes not only the case where they are added completely at the same time, but also the case where they are added with a very slight time difference. In other words, the simultaneous addition includes the case where one of the diamine and the dicarboxylic acid is added to the polycondensation reaction system first and then the other is added later, but rather the case where they are added at the same time.

[0015] In the step of obtaining a primary polycondensate by polycondensation in the presence of water, it is preferable to charge the diamine and dicarboxylic acid into a reaction vessel such as an autoclave and carry out the process while stirring. It is preferable to replace the atmosphere in the reaction vessel with nitrogen. The capacity of the reaction vessel is 1 L to 100 m ３ The size of the reaction vessel can be appropriately selected from the following. An example of the size of the reaction vessel is 1 to 10 L, another example is 10 L to 1000 L, and still another example is 1 m ３ ~100m ３ The stirring in the polycondensation reaction is preferably performed using a stirring blade. The stirring blade is preferably a double helical ribbon blade. Furthermore, in the production method of this embodiment, it is preferable to seal the polycondensation reaction by disposing a sealing liquid between the shaft of the stirring blade and the top plate of the reaction vessel. By adopting a mechanical seal system using such a sealing liquid, the reaction system is sealed even when high pressure is applied to the polycondensation reaction system, preventing leakage of diamines, dicarboxylic acids, polycondensates during synthesis, and the like. As a result, the composition of the polyamide resin can be more precisely designed, and polyamide resins of higher quality can be obtained. The type of sealing liquid is not particularly limited, but it preferably contains oil and / or water, and more preferably contains at least oil. Furthermore, when a mechanical seal system is adopted, either a single mechanical seal system or a double mechanical seal system may be used, with the double mechanical seal system being preferred.

[0016] In the production method of this embodiment, these diamines and dicarboxylic acids are polycondensed in the presence of water to obtain a primary polycondensate. For example, water is added to a reaction vessel along with the diamines and dicarboxylic acids. If necessary, a catalyst (preferably a phosphorus-based catalyst), an antioxidant, an end-capping agent, and the like may also be added. The amount of water added to the polycondensation reaction system is preferably 28% by mass or more, more preferably 30% by mass or more, even more preferably 32% by mass or more, and even more preferably 33% by mass or more, based on the total amount of substances present in the polycondensation reaction system. Setting the amount of water to above the lower limit tends to improve the fluidity of the reaction system and allow the initial polycondensation to proceed uniformly. Furthermore, the amount of water is preferably 80% by mass or less, more preferably 70% by mass or less, even more preferably 60% by mass or less, even more preferably 50% by mass or less, and even more preferably 40% by mass or less, based on the total amount of substances present in the polycondensation reaction system. Setting the amount of water below the upper limit tends to improve heating efficiency and reduce the amount of water distilled off in the subsequent step, thereby improving productivity. The "total amount of substances present in the polymerization reaction system" means the total amount of all substances (water, diamine, dicarboxylic acid, additives, etc.) present in the polymerization reaction system. One example is the total amount of water, diamine, dicarboxylic acid, additives, etc. introduced into the reaction vessel.

[0017] In the production method of this embodiment, the reaction temperature in the early polycondensation step (the maximum temperature reached in the reaction tank in the early polycondensation step) is preferably 100°C or higher, more preferably 115°C or higher, even more preferably 130°C or higher, even more preferably 145°C or higher, and even more preferably 155°C or higher. By setting the temperature at or above the lower limit, the formation of nylon salt (a salt of diamine and dicarboxylic acid) is promoted, and a high-quality primary polycondensate tends to be obtained in the subsequent late polycondensation. Furthermore, the reaction temperature in the early polycondensation step is preferably 220°C or lower, more preferably 190°C or lower, even more preferably 180°C or lower, and even more preferably 170°C or lower. By setting the temperature at or below the upper limit, deterioration of the diamine during the reaction is suppressed, and the molecular weight distribution of the polycondensate tends to be narrow. In the production method of this embodiment, it is preferable to gradually increase the temperature of the polycondensation reaction system until the maximum temperature reached in the early polycondensation step is reached, and typically, it is preferable to increase the temperature over a period of 3 to 120 minutes. The temperature rise rate of the polycondensation reaction system in the early polycondensation step is preferably 2° C. / min or more and 20° C. / min or less.

[0018] In the production method of this embodiment, the reaction time in the early polycondensation step (the reaction time after the maximum temperature is reached) is preferably 30 minutes or more and 120 minutes or less.

[0019] In the early polycondensation step, it is preferable to carry out the polycondensation reaction while applying pressure. The pressure is preferably 0.3 MPa or more, more preferably 0.4 MPa or more, even more preferably 0.5 MPa or more, and even more preferably 0.55 MPa or more. By setting the pressure at or above the lower limit, volatilization of the raw material monomers is suppressed, making it easier to obtain a resin composition with a target molecular weight. Furthermore, the pressure is preferably 2.5 MPa or less, more preferably 1.5 MPa or less, even more preferably 1.1 MPa or less, even more preferably 0.8 MPa or less, and even more preferably 0.65 MPa or less. By setting the pressure at or below the upper limit, the reaction temperature can be lowered, and productivity tends to improve.

[0020] In the production method of this embodiment, it is preferable to remove a portion of the water from the polycondensation reaction system and then further proceed with the polycondensation. By including a water-draining step, the progress of the polycondensation reaction is promoted, and a primary polycondensate with a higher molecular weight tends to be obtained. However, if the polycondensation reaction proceeds sufficiently without the water-draining step, the water-draining step may not be provided. If the water-draining step is not performed, it is preferable to proceed with the polycondensation reaction step under the same reaction temperature, reaction time, and reaction pressure as in the previous polycondensation step. In the water-draining step, it is preferable to gradually remove water; for example, it is preferable to remove 10% by mass of the total amount of water in the reaction system over 1 to 5 hours.

[0021] In the water-draining step, the amount of water present in the polycondensation reaction system is preferably 14% by mass or more and 40% by mass or less, relative to the total amount of substances present in the polycondensation reaction system. The amount of water present in the polycondensation reaction system after the water-draining step is more preferably 16% by mass or more, and even more preferably 18% by mass or more, relative to the total amount of substances present in the polycondensation reaction system. By setting the amount of water at or above the lower limit, the stirring torque during the reaction tends to be reduced, and the reaction tends to proceed uniformly. Note that if the amount of water present in the polycondensation reaction system is 10% by mass or less, relative to the total amount of substances present in the polycondensation reaction system, the reaction product tends to solidify in the reaction tank, making stirring difficult. Furthermore, the amount of water present in the polycondensation reaction system after the water-draining step is more preferably 33% by mass or less, more preferably 30% by mass or less, and even more preferably 27% by mass or less, relative to the total amount of substances present in the polycondensation reaction system. Setting the amount of water at or below the upper limit promotes the polycondensation reaction, and a primary polycondensate with a higher molecular weight tends to be obtained. The water here includes not only the water initially added to the polycondensation reaction system, but also the condensed water produced by polycondensation.

[0022] In the water-removing step, water may be removed all at once to reach the above amount, or water may be removed gradually during the water-removing step so that the above amount of water is maintained.

[0023] The reaction temperature in the water-removing step is preferably 140°C or higher, more preferably 155°C or higher, even more preferably 170°C or higher, even more preferably 175°C or higher, and even more preferably 195°C or higher. Setting the temperature at or above the lower limit tends to promote the distillation of water and the polycondensation of the pre-polycondensate. Furthermore, the reaction temperature in the water-removing step is preferably 240°C or lower, more preferably 215°C or lower, even more preferably 210°C or lower, and even more preferably 205°C or lower. Setting the temperature at or below the upper limit tends to suppress deterioration of the pre-polycondensate during the water-removing step. In the production method of this embodiment, the temperature is preferably gradually increased until it reaches the reaction temperature in the water-removing step, and typically, it is preferable to increase the temperature over a period of 3 to 120 minutes. The temperature-raising rate of the polycondensation reaction system in the water-removing step is preferably 1°C / min or higher, and preferably 10°C / min or lower.

[0024] In the manufacturing method of this embodiment, the reaction time in the water removal step (the reaction time after the maximum temperature is reached) is preferably 30 minutes or more, and is preferably 10 hours or less, and more preferably 7 hours or less.

[0025] In the water-removing step, it is preferable to carry out the polycondensation reaction under pressure. The pressure is preferably 0.5 MPa or more, more preferably 0.8 MPa or more, even more preferably 1.2 MPa or more, and even more preferably 1.5 MPa or more. By setting the pressure at or above the lower limit, unreacted monomers are prevented from being distilled off together with water, and deviations in the molar ratio of diamine to dicarboxylic acid tend to be less likely to occur. Furthermore, the pressure is preferably 2.5 MPa or less, more preferably 2.3 MPa or less, and even more preferably 2.1 MPa or less. By setting the pressure at or below the upper limit, deterioration of the polycondensate during the water-removing step tends to be suppressed.

[0026] The ratio of the stirring torque of the reaction tank in the water-draining step to the stirring torque of the reaction tank in the early polycondensation step (water-draining step / early polycondensation step) is preferably more than 1, and more preferably 1.1 or more. By making it equal to or greater than the lower limit, a higher molecular weight early polycondensate is obtained, which tends to be more likely to be highly molecular weight in the later polycondensation step. Furthermore, as the upper limit, a practical value is 20 times or less, and preferably 10 times or less. By making it equal to or less than the upper limit, the fluidity of the reaction system is maintained, and the reaction tends to proceed uniformly.

[0027] In this embodiment, it is preferable to further proceed with the polycondensation reaction after the water removal step. By including such a later polycondensation step, it becomes easier to obtain a primary polycondensate having a desired molecular weight.

[0028] The reaction temperature in the later polycondensation step is preferably 140°C or higher, more preferably 155°C or higher, even more preferably 170°C or higher, even more preferably 195°C or higher, and even more preferably 205°C or higher. By setting the temperature at or above the lower limit, the polycondensation reaction is promoted, and a primary polycondensate with a higher molecular weight tends to be obtained. Furthermore, the reaction temperature in the later polycondensation step is preferably 265°C or lower, more preferably 255°C or lower, even more preferably 245°C or lower, and even more preferably 240°C or lower. By setting the temperature at or below the upper limit, deterioration of the primary polycondensate during the reaction tends to be suppressed. In the production method of this embodiment, it is preferable to gradually increase the temperature until it reaches the reaction temperature of the later polycondensation step, and typically, it is preferable to increase the temperature over a period of 3 to 120 minutes. The temperature increase rate of the polycondensation reaction system in the later polycondensation step is preferably 1°C / min or higher, and preferably 10°C / min or lower.

[0029] The reaction time in the latter polycondensation step (the reaction time after the maximum temperature is reached) is preferably 30 minutes or more, and is preferably 10 hours or less, and more preferably 7 hours or less.

[0030] In the latter polycondensation step, it is preferable to carry out the polycondensation reaction under pressure. The pressure is preferably 0.5 MPa or more, more preferably 0.8 MPa or more, even more preferably 1.2 MPa or more, even more preferably 1.5 MPa or more, and may be 1.8 MPa or more. By setting the pressure at or above the lower limit, volatilization of unreacted monomers and low molecular weight components is suppressed, making it easier to obtain a polyamide resin with a target molecular weight. Furthermore, the pressure is preferably 3.5 MPa or less, more preferably 3.3 MPa or less, and even more preferably 3.1 MPa or less. By setting the pressure at or below the upper limit, deterioration of the polycondensate during the latter polycondensation step tends to be suppressed.

[0031] The amount of water present in the polycondensation reaction system in the later polycondensation step (e.g., the proportion of water in the total amount of substances present in the reaction tank) is preferably 14% by mass or more, more preferably 16% by mass or more, and even more preferably 18% by mass or more, relative to the total amount of substances present in the polycondensation reaction system. By setting the amount at or above the lower limit, the stirring torque tends to be reduced, and the reaction tends to proceed uniformly. Note that if the amount of water present in the polycondensation reaction system is 10% by mass or less, relative to the total amount of substances present in the polycondensation reaction system, the reaction product may solidify in the reaction tank, making stirring difficult. Furthermore, the amount of water present in the polycondensation reaction system during the later polycondensation step is preferably 40% by mass or less, more preferably 33% by mass or less, even more preferably 30% by mass or less, and even more preferably 27% by mass or less, relative to the total amount of substances present in the polycondensation reaction system. Setting the amount at or below the upper limit promotes the polycondensation reaction, and a primary polycondensate with a higher molecular weight tends to be obtained. The water here includes not only the water initially added to the polycondensation reaction system, but also the condensed water produced by polycondensation.

[0032] The production method of this embodiment includes increasing the degree of polymerization of the primary polycondensate. In the production method of this embodiment, when increasing the degree of polymerization of the primary polycondensate, it is preferable to withdraw the primary polycondensate from the reaction tank and increase the molecular weight. The withdrawal can be performed, for example, by providing a nozzle at the bottom of the reaction tank and withdrawing the primary polycondensate from the nozzle into a container at atmospheric pressure. Furthermore, in this embodiment, it is preferable to dry the primary polycondensate after withdrawing it from the reaction tank to obtain a powdery primary polycondensate. The amount of water in the reaction tank at the time of withdrawal is preferably 20% by mass or more and preferably 30% by mass or less, based on the total amount of substances present in the polycondensation reaction system. The withdrawal rate from the reaction tank is preferably 100 g / min or more and preferably 500 g / min or less. Furthermore, from the viewpoint of further reducing oxidative deterioration of the primary polycondensate, it is preferable to withdraw the primary polycondensate into a nitrogen atmosphere at atmospheric pressure.

[0033] The number average molecular weight of the primary polycondensate is preferably 500 or more, more preferably 800 or more, and may be 2000 or more. By setting it to the above lower limit or more, the subsequent polymerization degree tends to proceed easily, and a polyamide resin with a higher molecular weight tends to be obtained. Furthermore, the number average molecular weight of the primary polycondensate is preferably 10,000 or less, more preferably 7,000 or less, even more preferably 5,000 or less, even more preferably 4,000 or less, and even more preferably 3,600 or less. By setting it to the above upper limit or less, the flowability of the primary polycondensate tends to be improved, and the discharge during extraction tends to be more stable. Furthermore, the weight average molecular weight (Mw) of the primary polycondensate is preferably 1,000 or more, more preferably 3,000 or more, and even more preferably 4,000 or more. By setting it to the above lower limit or more, the subsequent polymerization degree tends to proceed easily, and a polyamide resin with a higher molecular weight tends to be obtained. The weight-average molecular weight (Mw) of the primary polycondensate is preferably 20,000 or less, more preferably 16,000 or less, and even more preferably 13,000 or less. By setting it to the upper limit or less, the flowability of the primary polycondensate tends to be improved, and discharge during extraction tends to be more stable. Furthermore, the dispersity (Mw / Mn) of the primary polycondensate is preferably 5.00 or less, more preferably 4.50 or less, even more preferably 4.20 or less, and may be 3.50 or less. By setting it to the upper limit or less, the dispersity of the polyamide resin obtained by subsequent high polymerization tends to be smaller, and the mechanical strength after molding tends to be improved. Furthermore, the dispersity (Mw / Mn) of the primary polycondensate may be 1.2 or more, or may be 2.0 or more. By setting it to the lower limit or more, the flowability of the polyamide resin obtained by subsequent high polymerization tends to be improved, and the moldability tends to be improved.

[0034] The ratio of the terminal amino group concentration to the terminal carboxyl group concentration of the primary polycondensate (amino group concentration / carboxyl group concentration) is preferably 0.9 to 1.1. By setting it in this range, the effects of the present invention tend to be more effectively exhibited.

[0035] The method for producing a polyamide resin according to this embodiment involves increasing the degree of polymerization of a primary polycondensate of a diamine and a dicarboxylic acid. By increasing the degree of polymerization, the number-average molecular weight of the polyamide resin is preferably increased by at least two times, and preferably by at most ten times. Known methods can be used to increase the degree of polymerization, such as solid-state polymerization and degassing extrusion, with solid-state polymerization being preferred. When performing solid-state polymerization, heating is preferably performed at 200°C or higher, more preferably at 230°C or higher, and preferably at 310°C or lower, more preferably at 280°C or lower. The heating time during solid-state polymerization is preferably 30 minutes to 20 hours, more preferably 1 to 3 hours. Specific examples of solid-state polymerization equipment include rotary dryers, vibration dryers, and conduction heating dryers (e.g., Torus Disk, manufactured by Hosokawa Micron Corporation, Solid Air, manufactured by Hosokawa Micron Corporation).

[0036] The number-average molecular weight of the polyamide resin obtained by the production method of this embodiment is preferably 1,000 or more, more preferably 3,000 or more, even more preferably 5,000 or more, and even more preferably 6,000 or more. The number-average molecular weight of the polyamide resin is preferably 30,000 or less, more preferably 20,000 or less, and even more preferably 13,000 or less. By setting it to the upper limit or less, the flowability during molding tends to be improved, and moldability tends to be improved. The weight-average molecular weight (Mw) of the polyamide resin obtained by the production method of this embodiment is preferably 3,000 or more, more preferably 8,000 or more, even more preferably 10,000 or more, even more preferably 20,000 or more, and even more preferably 30,000 or more. By setting it to the lower limit or more, the mechanical strength after molding tends to be further improved. The weight-average molecular weight (Mw) of the polyamide resin is preferably 100,000 or less, more preferably 80,000 or less, even more preferably 60,000 or less, even more preferably 50,000 or less, and even more preferably 45,000 or less. By setting it to the upper limit or less, the flowability during molding tends to be good and the moldability tends to be improved. Furthermore, the polydispersity (Mw / Mn) of the polyamide resin obtained by the production method of this embodiment is preferably 10.00 or less, more preferably 6.00 or less, even more preferably 5.50 or less, and may be 5.00 or less. By setting it to the upper limit or less, the mechanical strength after molding tends to be improved. Furthermore, the polydispersity (Mw / Mn) of the polyamide resin may be 1.20 or more, or may be 2.00 or more. By setting it to the lower limit or more, the flowability during molding tends to be good and the moldability tends to be improved.

[0037] Next, the polyamide resin obtained by the manufacturing method of this embodiment will be described. In this embodiment, the polyamide resin obtained by this embodiment is composed of diamine-derived structural units and dicarboxylic acid-derived structural units, and more than 30 mol% of the diamine-derived structural units are diamine-derived structural units represented by formula (1), and 20 mol% or more of the dicarboxylic acid-derived structural units are aromatic dicarboxylic acid-derived structural units. Formula (1) (In formula (1), R １ ~R ８ each independently represents a hydrogen atom or an aliphatic group having 1 to 5 carbon atoms. X1 and X2 each independently represent 1 or 2.

[0038] A first embodiment of the polyamide resin obtained in this embodiment is a polyamide resin that is composed of diamine-derived structural units and dicarboxylic acid-derived structural units, in which 50 mol % or more of the diamine-derived structural units are p-benzenediethaneamine-derived structural units, and 65 mol % or more of the dicarboxylic acid-derived structural units are aromatic dicarboxylic acid-derived structural units.

[0039] In the polyamide resin of the first embodiment, the proportion of p-benzenediethaneamine-derived structural units in the diamine-derived structural units is 50 mol% or more, preferably 60 mol% or more, more preferably 70 mol% or more, even more preferably 80 mol% or more, even more preferably 90 mol% or more, even more preferably 94 mol% or more, and may be 96 mol% or more, 98 mol%, or 99 mol% or more. By making the proportion above the lower limit, the temperature-lowering crystallization enthalpy change (ΔH) can be increased, and moldability tends to be improved. The upper limit of the proportion of p-benzenediethaneamine-derived structural units in the diamine-derived structural units is 100 mol%.

[0040] The polyamide resin of the first embodiment may contain, as a diamine-derived structural unit, a structural unit derived from a diamine other than the structural unit derived from p-benzenediethaneamine. Examples of such a structural unit include m-benzenediethaneamine, o-benzenediethaneamine, aliphatic diamines, alicyclic diamines, and aromatic diamines other than benzenediethaneamine, with m-benzenediethaneamine being preferred. The polyamide resin of the first embodiment may contain only one type of structural unit derived from another diamine, or may contain two or more types. When the polyamide resin of the first embodiment contains a structural unit derived from m-benzenediethaneamine as a diamine-derived structural unit, it is preferred that the structural unit derived from p-benzenediethaneamine be 70 to 99 mol % (preferably 80 mol % or more, more preferably 90 mol % or more, and even more preferably 93 mol % or more) and the structural unit derived from m-benzenediethaneamine be 1 to 30 mol % (preferably 20 mol % or less, more preferably 10 mol % or less, and even more preferably 7 mol % or less).

[0041] As the aliphatic diamine, a wide variety of known aliphatic diamines can be used, and aliphatic diamines having 6 to 12 carbon atoms are preferred. Examples of such aliphatic diamines include linear aliphatic diamines such as 1,6-hexanediamine, 1,7-heptanediamine, 1,8-octanediamine, 1,9-nonanediamine, 1,10-decanediamine, 1,11-undecanediamine, and 1,12-dodecanediamine, and branched aliphatic diamines such as 2-methyl-1,8-octanediamine, 4-methyl-1,8-octanediamine, 5-methyl-1,9-nonanediamine, 2,2,4- / 2,4,4-trimethylhexamethylenediamine, 2-methyl-1,5-pentanediamine, 2-methyl-1,6-hexanediamine, and 2-methyl-1,7-heptanediamine. As the alicyclic diamine, a wide variety of known alicyclic diamines can be used, and examples thereof include 1,2-bis(aminomethyl)cyclohexane, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, isophoronediamine, 4,4'-thiobis(cyclohexane-1-amine), and 4,4'-thiobis(cyclohexane-1-amine).

[0042] For other aromatic diamines, please refer to the description in paragraph 0052 of WO 2017 / 126409, the contents of which are incorporated herein by reference.

[0043] In the polyamide resin of the first embodiment, the proportion of aromatic dicarboxylic acid-derived structural units in the dicarboxylic acid-derived structural units is 65 mol% or more. By setting the proportion at or above the lower limit, a polyamide resin with a higher melting point and a higher glass transition temperature tends to be obtained. In the polyamide resin of the first embodiment, the proportion of aromatic dicarboxylic acid-derived structural units in the dicarboxylic acid-derived structural units is 65 mol% or more, preferably 70 mol% or more, more preferably 75 mol% or more, even more preferably 80 mol% or more, even more preferably 90 mol% or more, and even more preferably 94 mol% or more. Depending on the application, it may be 96 mol% or more, 98 mol%, or 99 mol% or more. The upper limit may be 100 mol%, but may be 97 mol% or less depending on the application. The polyamide resin of the first embodiment may contain only one type of aromatic dicarboxylic acid-derived structural unit, or may contain two or more types. When two or more types are contained, the total amount is preferably within the above range.

[0044] A preferred example of the aromatic dicarboxylic acid in the first embodiment is phenylenedicarboxylic acid. Another preferred example of the aromatic dicarboxylic acid in the first embodiment is an aromatic dicarboxylic acid represented by formula (FC). Formula (FC) HOOC—(CH ２ ) ｍ -Aromatic ring structure-(CH ２ ) ｍ —COOH (In formula (FC), m represents 0, 1 or 2.)

[0045] m is preferably 0 or 1, and more preferably 0.

[0046] In formula (FC), the aromatic ring structure is a structure containing an aromatic ring, and is preferably a structure consisting of only an aromatic ring or a structure consisting of only an aromatic ring and a substituent thereof, and more preferably a structure consisting of only an aromatic ring. Examples of substituents that the aromatic ring may have include an alkyl group having 1 to 3 carbon atoms or a halogen atom. It is preferable that the aromatic ring is not substituted with a halogen atom. The aromatic ring structure may be either a monocyclic or condensed ring, and is preferably a monocyclic ring. In addition, the number of carbon atoms constituting the aromatic ring is not particularly limited, but a 4- to 15-membered ring is preferred. More specifically, the aromatic ring structure is preferably a benzene ring, a naphthalene ring, or one having a substituent on these rings, and more preferably a benzene ring or one having a substituent on the benzene ring.

[0047] More specifically, in the first embodiment, examples of the aromatic dicarboxylic acid include isophthalic acid, terephthalic acid, orthophthalic acid, phenylene diacetic acid (o-phenylene diacetic acid, p-phenylene diacetic acid, m-phenylene diacetic acid), and naphthalene dicarboxylic acid (1,2-naphthalene dicarboxylic acid, 1,3-naphthalene dicarboxylic acid, 1,4-naphthalene dicarboxylic acid, 1,5-naphthalene dicarboxylic acid, 1,6-naphthalene dicarboxylic acid, 1,7-naphthalene dicarboxylic acid, 1,8-naphthalene dicarboxylic acid, 2,3-naphthalene dicarboxylic acid, 2,6-naphthalene dicarboxylic acid, and 2,7-naphthalene dicarboxylic acid). Among these, isophthalic acid, terephthalic acid, and phenylene diacetic acid are preferred, isophthalic acid and phenylene diacetic acid are more preferred, and isophthalic acid is even more preferred. In particular, it is preferable that 90 mol% or more, more preferably 95 mol% or more, even more preferably 98 mol% or more, and even more preferably 99 mol% or more of the aromatic dicarboxylic acid be the aromatic dicarboxylic acid. In particular, by using isophthalic acid, the temperature-lowering crystallization enthalpy change (ΔH) can be increased, improving moldability. In addition, the mass loss rate can be reduced. On the other hand, when phenylene diacetic acid is used in the polyamide resin of the first embodiment, it is preferable that the polyamide resin contains 50 to 100 mol% of p-phenylene diacetic acid and 50 to 0 mol% of m-phenylene diacetic acid.

[0048] Next, preferred embodiments of the dicarboxylic acid-derived structural units in the polyamide resin of the first embodiment will be described. A preferred form A of the dicarboxylic acid-derived structural units in the first embodiment is a form in which more than 95 mol% of the dicarboxylic acid-derived structural units are structural units derived from aromatic dicarboxylic acids. By having more than 95 mol% of the dicarboxylic acid-derived structural units be aromatic dicarboxylic acids, it is possible to reduce the mass loss rate while maintaining a high melting point and a high glass transition temperature. Furthermore, it is possible to increase the temperature-lowering crystallization enthalpy change (ΔH), which tends to further improve moldability. In addition, it is possible to reduce the amount of outgassing.

[0049] In the preferred form A of the dicarboxylic acid-derived structural units in the first embodiment, the proportion of aromatic dicarboxylic acid-derived structural units in the dicarboxylic acid-derived structural units is preferably 96 mol% or more, more preferably 97 mol% or more, even more preferably 98 mol% or more, and even more preferably 99 mol% or more. By making it equal to or greater than the lower limit, the temperature-lowering crystallization enthalpy change (ΔH) can be increased, and moldability tends to be further improved. Furthermore, the upper limit of the proportion of aromatic dicarboxylic acid-derived structural units in the dicarboxylic acid-derived structural units may be 100 mol%.

[0050] In the preferred form A of the dicarboxylic acid-derived structural unit in the first embodiment, the aromatic dicarboxylic acid is preferably an aromatic dicarboxylic acid represented by the above formula (FC), more preferably selected from isophthalic acid, terephthalic acid, and phenylene diacetic acid, even more preferably isophthalic acid and / or phenylene diacetic acid, and even more preferably isophthalic acid. In particular, preferably 90 mol% or more, more preferably 95 mol% or more, even more preferably 98 mol% or more, and even more preferably 99 mol% or more of the aromatic dicarboxylic acid-derived structural units are the aromatic dicarboxylic acid-derived structural units. In particular, by using isophthalic acid, the temperature-lowering crystallization enthalpy change (ΔH) can be increased, improving moldability. In addition, the mass loss rate can be reduced.

[0051] In the preferred form A of the dicarboxylic acid-derived structural units in the first embodiment, when phenylene diacetic acid is used, the aromatic dicarboxylic acid preferably contains 50 to 100 mol % of p-phenylene diacetic acid and 50 to 0 mol % of m-phenylene diacetic acid. The total of p-phenylene diacetic acid and m-phenylene diacetic acid is 100 mol % or less, and preferably 97 to 100 mol %, of all dicarboxylic acid-derived structural units.

[0052] In the polyamide resin of the first embodiment, a preferred form B of the dicarboxylic acid-derived structural units is a form in which 65 to 97 mol% of the dicarboxylic acid-derived structural units are aromatic dicarboxylic acid-derived structural units and 3 to 35 mol% are alicyclic dicarboxylic acid-derived structural units. The sum of the aromatic dicarboxylic acid-derived structural units and the alicyclic dicarboxylic acid-derived structural units is 100 mol% or less, preferably 97 to 100 mol%, of the total dicarboxylic acid-derived structural units. In a preferred form B of the dicarboxylic acid-derived structural units of the first embodiment, the dicarboxylic acid-derived structural units are composed of an aromatic dicarboxylic acid and an alicyclic dicarboxylic acid. This structure allows for a low mass loss rate while maintaining a high melting point and a high glass transition temperature. Furthermore, the temperature-lowering crystallization enthalpy change (ΔH) can be increased, tending to further improve moldability. In addition, the amount of outgassing can be reduced.

[0053] In the preferred form B of the dicarboxylic acid-derived structural unit in the first embodiment, the proportion of aromatic dicarboxylic acid in the dicarboxylic acid-derived structural unit is 65 mol% or more, preferably 70 mol% or more, more preferably 75 mol% or more, even more preferably 80 mol% or more, even more preferably 85 mol% or more, and even more preferably 88 mol% or more. By setting it to the lower limit or more, a polyamide resin with a higher melting point and a higher glass transition temperature tends to be obtained. Furthermore, the proportion of aromatic dicarboxylic acid in the dicarboxylic acid-derived structural unit is 97 mol% or less, preferably 96 mol% or less, and may be 94 mol% or less, or 92 mol% or less. By setting it to the upper limit or less, the mass loss rate can be reduced, and thermal stability during molding tends to be further improved.

[0054] In the preferred form B of the dicarboxylic acid-derived structural units in the first embodiment, the proportion of alicyclic dicarboxylic acid in the dicarboxylic acid-derived structural units is 3 mol% or more, preferably 4 mol% or more, and may be 6 mol% or more, or even 8 mol% or more. By setting the proportion at or above the lower limit, the mass loss rate can be further reduced, and thermal stability during molding tends to be further improved. Furthermore, the proportion of alicyclic dicarboxylic acid in the dicarboxylic acid-derived structural units is 35 mol% or less, preferably 30 mol% or less, more preferably 25 mol% or less, even more preferably 20 mol% or less, even more preferably 15 mol% or less, and even more preferably 12 mol% or less. By setting the proportion at or below the upper limit, the temperature-lowering crystallization enthalpy change (ΔH) can be further increased, and moldability can be further improved. In particular, by setting the proportion of alicyclic dicarboxylic acid-derived structural units in the dicarboxylic acid-derived structural units to 8 to 12 mol%, a high melting point, high glass transition temperature, high ΔH, low mass loss rate, and low outgassing can be achieved in a balanced manner.

[0055] In the preferred form B of the dicarboxylic acid-derived structural unit in the first embodiment, the aromatic dicarboxylic acid is preferably an aromatic dicarboxylic acid represented by the above formula (FC), more preferably selected from isophthalic acid, terephthalic acid, and phenylene diacetic acid, even more preferably isophthalic acid and phenylene diacetic acid, and even more preferably isophthalic acid. In particular, it is preferable that 90 mol% or more, more preferably 95 mol% or more, even more preferably 98 mol% or more, and even more preferably 99 mol% or more of the aromatic dicarboxylic acid is the aromatic dicarboxylic acid. The upper limit is 100 mol%.

[0056] In the preferred form B of the dicarboxylic acid-derived structural unit in the first embodiment, the alicyclic dicarboxylic acid is not particularly limited, and known alicyclic dicarboxylic acids can be used. Specific examples include alicyclic dicarboxylic acids having 6 to 20 carbon atoms. The alicyclic dicarboxylic acid is preferably an alicyclic dicarboxylic acid represented by formula (FA), and more preferably cyclohexanedicarboxylic acid (preferably a mixture of trans-cyclohexanedicarboxylic acid and cis-cyclohexanedicarboxylic acid). In particular, it is preferable that 90 mol % or more, more preferably 95 mol % or more, even more preferably 98 mol % or more, and even more preferably 99 mol % or more of the alicyclic dicarboxylic acid be the alicyclic dicarboxylic acid. The upper limit is 100 mol %. Formula (FA) HOOC-(CH ２ ) ｎ -Alicyclic structure-(CH ２ ) ｎ —COOH (In formula (FA), n represents 0, 1 or 2.)

[0057] n is preferably 0 or 1, and more preferably 0.

[0058] The alicyclic structure is a structure containing an alicyclic ring, and is preferably a structure consisting of only an alicyclic ring, or a structure consisting of only an alicyclic ring and a substituent thereof, with a structure consisting of only an alicyclic ring being more preferred. Examples of substituents that the alicyclic structure may have include an alkyl group having 1 to 3 carbon atoms or a halogen atom. It is preferable that the alicyclic structure does not have a halogen atom as a substituent. The alicyclic structure may be either a monocyclic or condensed ring, with a monocyclic structure being preferred. The number of carbon atoms constituting the ring is not particularly limited, but a 4- to 10-membered ring is preferred. In the preferred form B of the dicarboxylic acid-derived structural unit, the alicyclic structure is preferably a cyclohexane ring.

[0059] In the preferred form B of the dicarboxylic acid-derived structural unit in the first embodiment, the cyclohexanedicarboxylic acid may be either a cis or trans isomer, but a mixture of a trans cyclohexanedicarboxylic acid and a cis cyclohexanedicarboxylic acid is preferred. Using a mixture can produce a polyamide resin with a higher glass transition temperature and a lower mass loss rate. The cyclohexanedicarboxylic acid is preferably 1,4-cyclohexanedicarboxylic acid and / or 1,3-cyclohexanedicarboxylic acid, and even more preferably 1,4-cyclohexanedicarboxylic acid. Using such a compound can lower the mass loss rate and further improve thermal stability during molding.

[0060] Specific examples of alicyclic dicarboxylic acids that can be used in the preferred form B of the dicarboxylic acid-derived structural unit include, in addition to the above, 4,4'-methylenebis(2-methylcyclohexane-1-carboxylic acid), 4,4'-methylenebis(cyclohexane-1-carboxylic acid), 4,4'-oxobis(cyclohexane-1-carboxylic acid), and 4,4'-thiobis(cyclohexane-1-carboxylic acid).

[0061] The polyamide resin of the first embodiment may contain a structural unit derived from a dicarboxylic acid other than the above, regardless of whether the structural unit derived from the dicarboxylic acid is in the preferred form A or the preferred form B. When the other dicarboxylic acid is contained, the proportion thereof is preferably 3 mol% or less, more preferably 1 mol% or less, of the total structural units derived from the dicarboxylic acid. The polyamide resin of the first embodiment may contain only one type of structural unit derived from the other dicarboxylic acid, or may contain two or more types.

[0062] Examples of dicarboxylic acids constituting the dicarboxylic acid-derived structural units that the polyamide resin of the first embodiment may contain include aliphatic dicarboxylic acids. Known aliphatic dicarboxylic acids can be used as the aliphatic dicarboxylic acids, and examples include succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, and dodecanedicarboxylic acid. Furthermore, the polyamide resin of the first embodiment may be configured to be substantially free of structural units derived from aliphatic dicarboxylic acids. "Substantially free" means that the proportion of structural units derived from aliphatic dicarboxylic acids among the structural units derived from dicarboxylic acids is 5 mol% or less, preferably 3 mol% or less, and more preferably 1 mol% or less.

[0063] Furthermore, in the polyamide resin of the first embodiment, it is preferable that more than 95 mol% (preferably 96 mol% or more, more preferably 98 mol% or more, and 100 mol% or less) of the diamine-derived structural units and dicarboxylic acid-derived structural units are structural units having a cyclic structure. By adopting such a structure, a polyamide resin having a high melting point and a high glass transition temperature can be obtained. In addition, the mass loss rate can be reduced. Furthermore, the temperature-lowering crystallization enthalpy change (ΔH) can be increased, which tends to further improve moldability. In addition, the amount of outgassing can be reduced. A structural unit having a cyclic structure means that the structural unit contains a cyclic structure such as an aromatic ring or an alicyclic ring, and preferably contains either an aromatic ring or an alicyclic ring.

[0064] The polyamide resin of the first embodiment is composed of dicarboxylic acid-derived structural units and diamine-derived structural units, but may also contain structural units other than the dicarboxylic acid-derived structural units and diamine-derived structural units, as well as other moieties such as terminal groups. Examples of other structural units include, but are not limited to, structural units derived from lactams such as ε-caprolactam, valerolactam, laurolactam, and undecalactam, and aminocarboxylic acids such as 11-aminoundecanoic acid and 12-aminododecanoic acid. Furthermore, the polyamide resin of the first embodiment may contain trace components such as additives used in the synthesis. The polyamide resin of the first embodiment preferably comprises 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, and even more preferably 98% by mass or more of dicarboxylic acid-derived structural units and diamine-derived structural units.

[0065] A second embodiment of the polyamide resin obtained in this embodiment is a polyamide resin composed of diamine-derived structural units and dicarboxylic acid-derived structural units, in which 50 mol % or more of the diamine-derived structural units are structural units derived from p-benzenediethaneamine, 20 mol % or more but less than 95 mol % of the dicarboxylic acid structural units are structural units derived from aromatic dicarboxylic acid, and more than 5 mol % but 80 mol % or less are structural units derived from an α,ω-linear aliphatic dicarboxylic acid having 4 to 15 carbon atoms.

[0066] In the polyamide resin of the second embodiment, the proportion of p-benzenediethaneamine-derived structural units in the diamine-derived structural units is 50 mol% or more. By including 50 mol% or more of p-benzenediethaneamine-derived structural units, moldability tends to be improved. The proportion of p-benzenediethaneamine-derived structural units in the diamine-derived structural units is preferably 60 mol% or more, more preferably 70 mol% or more, even more preferably 80 mol% or more, even more preferably 90 mol% or more, even more preferably 94 mol% or more, and may be 96 mol% or more, 98 mol%, or 99 mol% or more. The upper limit of the proportion of p-benzenediethaneamine-derived structural units in the diamine-derived structural units is 100 mol%.

[0067] The polyamide resin of the second embodiment may contain, as a diamine-derived structural unit, a structural unit derived from a diamine other than the structural unit derived from p-benzenediethaneamine. Examples of such other structural units include m-benzenediethaneamine, o-benzenediethaneamine, aliphatic diamines, alicyclic diamines, and aromatic diamines other than benzenediethaneamine, with m-benzenediethaneamine being preferred. The polyamide resin of the second embodiment may contain only one type of structural unit derived from another diamine, or may contain two or more types. When the polyamide resin of the second embodiment contains m-benzenediethaneamine-derived structural units as a diamine-derived structural unit, it is preferred that the p-benzenediethaneamine-derived structural unit account for 70 to 99 mol% (preferably 80 mol% or more, more preferably 90 mol% or more, and even more preferably 93 mol% or more) and the m-benzenediethaneamine-derived structural unit account for 1 to 30 mol% (preferably 20 mol% or less, more preferably 10 mol% or less, and even more preferably 7 mol% or less).

[0068] The aliphatic diamines, alicyclic diamines, and other aromatic diamines have the same meanings as the aliphatic diamines, alicyclic diamines, and other aromatic diamines described in the section on the polyamide resin of the first embodiment, and the preferred ranges are also the same.

[0069] In the polyamide resin of the second embodiment, the proportion of aromatic dicarboxylic acid-derived structural units (preferably isophthalic acid) among the dicarboxylic acid-derived structural units is 20 mol% or more and less than 95 mol%. By setting the proportion at or above the lower limit, a polyamide resin with a higher melting point and a higher glass transition temperature can be obtained. In addition, the elastic modulus of the molded product tends to be further improved. On the other hand, by setting the proportion at or below the upper limit, the mass loss rate can be reduced and thermal stability during molding can be improved. In the polyamide resin of the second embodiment, the proportion of aromatic dicarboxylic acid-derived structural units among the dicarboxylic acid-derived structural units is 20 mol% or more, preferably 30 mol% or more, more preferably 40 mol% or more, and even more preferably 45 mol% or more. Depending on the application, it may be 55 mol% or more, 60 mol%, or 65 mol% or more. The upper limit is less than 95 mol%, preferably 94 mol% or less, more preferably 93 mol% or less, even more preferably 92 mol% or less, even more preferably 91 mol% or less, even more preferably 90 mol% or less, and even more preferably 88 mol% or less. The polyamide resin of the second embodiment may contain only one type of aromatic dicarboxylic acid-derived structural unit, or may contain two or more types. When two or more types are contained, it is preferable that the total amount is within the above range.

[0070] The details of the aromatic dicarboxylic acid in the second embodiment are the same as those described in the section on the aromatic dicarboxylic acid in the first embodiment, and the preferred ranges are also the same.

[0071] In the polyamide resin of the second embodiment, the proportion of structural units derived from an α,ω-linear aliphatic dicarboxylic acid having 4 to 15 carbon atoms in the structural units derived from dicarboxylic acids is more than 5 mol % and not more than 80 mol %. By making the proportion not less than the lower limit, it is possible to reduce the mass loss rate during heating and further improve the thermal stability during molding, and by making the proportion not more than the upper limit, the elastic modulus of the molded article is further improved.

[0072] In the polyamide resin of the second embodiment, the proportion of structural units derived from an α,ω-linear aliphatic dicarboxylic acid having 4 to 15 carbon atoms (preferably sebacic acid) among the structural units derived from dicarboxylic acids is greater than 5 mol%, preferably 6 mol% or more, more preferably 7 mol% or more, even more preferably 8 mol% or more, even more preferably 9 mol% or more, even more preferably 10 mol% or more, and even more preferably 12 mol% or more. The upper limit is 80 mol% or less, preferably 70 mol% or less, more preferably 60 mol% or less, and even more preferably 55 mol% or less. Depending on the application, it may be 45 mol% or less, 40 mol% or less, or 35 mol% or less. By setting it below the upper limit, the elastic modulus of the molded article tends to be further improved. Furthermore, by setting it above the lower limit, the mass loss rate upon heating can be reduced, and thermal stability during molding tends to be further improved. The polyamide resin of the second embodiment may contain only one type of structural unit derived from an α,ω-linear aliphatic dicarboxylic acid having 4 to 15 carbon atoms, or may contain two or more types. When two or more types are contained, it is preferable that the total amount is in the above range.

[0073] In the second embodiment, preferred examples of the C4 to C15 α,ω-linear aliphatic dicarboxylic acid are succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, and dodecanedicarboxylic acid, with adipic acid and sebacic acid being more preferred. In particular, it is preferred that 90 mol % or more, more preferably 95 mol % or more, even more preferably 98 mol % or more, and even more preferably 99 mol % or more of the C4 to C15 α,ω-linear aliphatic dicarboxylic acids be sebacic acid.

[0074] For the polyamide resin of the second embodiment, it is particularly preferred that 40 to 90 mol% of the dicarboxylic acid-derived structural units are structural units derived from aromatic dicarboxylic acids (preferably aromatic dicarboxylic acids selected from isophthalic acid, terephthalic acid, and phenylene diacetic acid, more preferably isophthalic acid), and 10 to 60 mol% are structural units derived from α,ω-linear aliphatic dicarboxylic acids having 4 to 15 carbon atoms (preferably adipic acid and / or sebacic acid, more preferably sebacic acid). The total of the structural units derived from aromatic dicarboxylic acids and the α,ω-linear aliphatic dicarboxylic acids having 4 to 15 carbon atoms is 100 mol% or less, preferably 97 to 100 mol%.

[0075] The polyamide resin of the second embodiment may contain structural units derived from other dicarboxylic acids other than those mentioned above. When other dicarboxylic acids are contained, the proportion thereof is preferably 3 mol% or less, more preferably 1 mol% or less, of the total structural units derived from dicarboxylic acids. The polyamide resin of the second embodiment may contain only one type of structural unit derived from other dicarboxylic acids, or may contain two or more types.

[0076] Examples of dicarboxylic acids constituting the dicarboxylic acid-derived structural units that the polyamide resin of the second embodiment may contain include alicyclic dicarboxylic acids. Examples of alicyclic dicarboxylic acids include cyclohexanedicarboxylic acid, 4,4'-methylenebis(2-methylcyclohexane-1-carboxylic acid), 4,4'-methylenebis(cyclohexane-1-carboxylic acid), 4,4'-oxobis(cyclohexane-1-carboxylic acid), and 4,4'-thiobis(cyclohexane-1-carboxylic acid). The polyamide resin of the second embodiment may be configured to be substantially free of alicyclic dicarboxylic acids. "Substantially free" means that the proportion of alicyclic dicarboxylic acid-derived structural units among the dicarboxylic acid-derived structural units is 5 mol% or less, preferably 3 mol% or less, and more preferably 1 mol% or less.

[0077] The polyamide resin of the second embodiment is composed of dicarboxylic acid-derived structural units and diamine-derived structural units, but may also contain structural units other than the dicarboxylic acid-derived structural units and diamine-derived structural units, as well as other moieties such as terminal groups. Examples of other structural units include, but are not limited to, lactams such as ε-caprolactam, valerolactam, laurolactam, and undecalactam, and structural units derived from aminocarboxylic acids such as 11-aminoundecanoic acid and 12-aminododecanoic acid. Furthermore, the polyamide resin of the second embodiment may contain trace components such as additives used in the synthesis. The polyamide resin of the second embodiment preferably comprises 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, and even more preferably 98% by mass or more of dicarboxylic acid-derived structural units and diamine-derived structural units.

[0078] A third embodiment of the polyamide resin obtained in this embodiment is a polyamide resin that is composed of diamine-derived structural units and dicarboxylic acid-derived structural units, in which 70 to 97 mol % of the diamine-derived structural units are derived from p-benzenediethaneamine, and 3 to 30 mol % are derived from a diamine represented by formula (1-1), and 50 mol % or more of the dicarboxylic acid-derived structural units are derived from an aromatic dicarboxylic acid. (In formula (1-1), R １１ ~R １８ each independently represents a hydrogen atom or an aliphatic group having 1 to 5 carbon atoms; R １１ ~R １４ and at least one of R １５ ~R １８ At least one of the groups is an aliphatic group having 1 to 5 carbon atoms.

[0079] Furthermore, in a third embodiment, 70 to 97 mol % of the diamine-derived structural units are derived from p-benzenediethaneamine, and 3 to 30 mol % are derived from the diamine represented by formula (1-1). The total of p-benzenediethaneamine and the diamine represented by formula (1-1) does not exceed 100 mol %, preferably 90 to 100 mol %, more preferably 95 to 100 mol %, and even more preferably 99 to 100 mol %. In the third embodiment, the proportion of p-benzenediethaneamine-derived structural units in the diamine-derived structural units is 70 mol % or more, preferably 75 mol % or more, more preferably 80 mol % or more, even more preferably 84 mol % or more, even more preferably 88 mol % or more, and even more preferably 91 mol % or more. By ensuring that the proportion is equal to or greater than the above lower limit, mechanical properties at high temperatures tend to be more excellent. Furthermore, in this embodiment, the proportion of the p-benzenediethaneamine-derived structural units in the diamine-derived structural units is 97 mol% or less, preferably 96 mol% or less, and may be 94 mol% or less. By setting the proportion to the upper limit or less, the mass loss rate at temperatures slightly higher than the melting point tends to be low, and thermal stability during molding tends to be improved. In this embodiment, the proportion of the diamine-derived structural units represented by formula (1-1) in the diamine-derived structural units is 3 mol% or more, preferably 4 mol% or more, and may be 6 mol% or more. By setting the proportion to the lower limit or more, the mass loss rate at temperatures slightly higher than the melting point tends to be low, and thermal stability during molding tends to be improved. In a third embodiment, the proportion of the diamine-derived structural units represented by formula (1-1) in the diamine-derived structural units is 30 mol% or less, preferably 25 mol% or less, more preferably 20 mol% or less, even more preferably 16 mol% or less, even more preferably 12 mol% or less, and even more preferably 9 mol% or less. By setting the content to be equal to or less than the upper limit, the mechanical properties at high temperatures tend to be better. In the third embodiment, the diamine-derived structural unit may contain only one type of diamine represented by formula (1-1), or may contain two or more types of diamines.When two or more types are contained, the total amount is preferably within the above range.

[0080] Next, a diamine represented by formula (1-1) in a third embodiment will be described. In this embodiment, the diamine represented by formula (1-1) has at least one aliphatic group having 1 to 5 carbon atoms substituted on the ethylene chain portion of p-benzenediethaneamine. It is presumed that the presence of such an aliphatic group inhibits hydrogen bonding between amide groups and stacking of aromatic rings without significantly changing the distance between amide groups in the molecular chain, thereby lowering the melting point to some extent and reducing the mass loss rate at temperatures slightly higher than the melting point. As a result, it is presumed that the effect of improving thermal stability during molding and processing is more effectively exerted. In formula (1-1), R １１ ~R １８ each independently represents a hydrogen atom or an aliphatic group having 1 to 5 carbon atoms; R １１ ~R １４ and at least one of R １５ ~R １８ At least one of the aliphatic groups has 1 to 5 carbon atoms. The aliphatic group having 1 to 5 carbon atoms is preferably an aliphatic group having 1 to 3 carbon atoms, and more preferably an aliphatic group having 1 or 2 carbon atoms. Examples of the aliphatic group include an alkyl group, an alkenyl group, and an alkynyl group, with an alkyl group being preferred, and a straight-chain alkyl group being more preferred. Examples of the alkyl group include a methyl group, an ethyl group, an i-propyl group, an i-butyl group, and a t-butyl group, with a methyl group and an ethyl group being preferred, and a methyl group being more preferred. In formula (1-1), R １１ ~R １４ and at least one of R １５ ~R １８ At least two of R are preferably aliphatic groups having 1 to 5 carbon atoms, １１ ~R １４ Two of these and R １５ ~R １８ It is more preferable that both of R are aliphatic groups having 1 to 5 carbon atoms. １１ ~R １８ Preferably, each independently represents a hydrogen atom or a methyl group. More preferably, R １１and / or R １２ , and R １７ and / or R １８ is a hydrogen atom, and R １１ , R １２ , R １７ and R １８ Among these, those that are not hydrogen atoms are methyl groups, and R １３ , R １４ , R １５ and R １６ is a hydrogen atom or a methyl group (preferably a methyl group). More preferably, R １１ , R １２ , R １７ and R １８ is a hydrogen atom, and R １３ , R １４ , R １５ and R １６ is a hydrogen atom or a methyl group (preferably a methyl group). Use of such a compound increases the reactivity of the amino group in the diamine represented by formula (1-1), which tends to facilitate polymerization and increase productivity.

[0081] Furthermore, in the third embodiment, in formula (1-1), R １１ ~R １４ and at least two (preferably two) of １５ ~R １８ wherein at least two (preferably two) of the above are aliphatic groups having 1 to 5 carbon atoms (compound 1-1), and １１ ~R １４ One of and R １５ ~R １８ In the case of a mixture, the mass ratio of Compound 1-1 to Compound 1-2 is preferably 1:0.1 to 1:1.

[0082] In the third embodiment, the diamine-derived structural units may contain other structural units than those described above. Examples of such other structural units include m-benzenediethaneamine, o-benzenediethaneamine, aliphatic diamines, alicyclic diamines, and structural units derived from aromatic diamines other than benzenediethaneamine and the diamine represented by formula (1-1). The polyamide resin of the third embodiment may contain only one type of other diamine-derived structural unit, or may contain two or more types.

[0083] The aliphatic diamines, alicyclic diamines, and other aromatic diamines have the same meanings as the aliphatic diamines, alicyclic diamines, and other aromatic diamines described in the section on the polyamide resin of the first embodiment, and the preferred ranges are also the same.

[0084] In the polyamide resin of the third embodiment, 50 mol% or more of the dicarboxylic acid-derived structural units are derived from an aromatic dicarboxylic acid (preferably isophthalic acid). By including structural units derived from an aromatic dicarboxylic acid, a polyamide resin with a higher melting point and a higher glass transition temperature tends to be obtained. In the third embodiment, the proportion of structural units derived from aromatic dicarboxylic acid in the dicarboxylic acid-derived structural units is 50 mol% or more, preferably 70 mol% or more, more preferably 80 mol% or more, even more preferably 90 mol% or more, even more preferably more than 95 mol%, and even more preferably 99 mol% or more. By setting the proportion at or above the lower limit, the crystallinity of the polyamide resin tends to be improved, and the crystallinity of the molded product and the strength when molded at high temperatures tend to be improved. In this embodiment, the upper limit of the proportion of structural units derived from aromatic dicarboxylic acid in the dicarboxylic acid-derived structural units is 100 mol% or less.

[0085] The details of the aromatic dicarboxylic acid in the third embodiment are the same as those described in the section on the aromatic dicarboxylic acid in the first embodiment, and the preferred ranges are also the same.

[0086] The polyamide resin of this embodiment may contain dicarboxylic acid-derived structural units other than those derived from aromatic dicarboxylic acids. Examples of dicarboxylic acids constituting dicarboxylic acid-derived structural units other than those derived from aromatic dicarboxylic acids include aliphatic dicarboxylic acids. Known aliphatic dicarboxylic acids can be used as the aliphatic dicarboxylic acids, and examples include succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, and dodecanedicarboxylic acid. Furthermore, a third embodiment of the polyamide resin may be substantially free of aliphatic dicarboxylic acid-derived structural units. "Substantially free" means that the proportion of aliphatic dicarboxylic acid-derived structural units in the dicarboxylic acid-derived structural units is 5 mol% or less, preferably 3 mol% or less, and more preferably 1 mol% or less.

[0087] In a third embodiment of the polyamide resin, it is preferable that more than 95 mol% (preferably 96 mol% or more, more preferably 98 mol% or more, and 100 mol% or less) of the diamine-derived structural units and dicarboxylic acid-derived structural units are structural units having a cyclic structure. This configuration results in a polyamide resin with a high melting point and a high glass transition temperature. It also reduces the mass loss rate. Furthermore, the enthalpy change (ΔH) during melting can be reduced, which tends to further improve moldability. In addition, the amount of outgassing can be reduced. A structural unit having a cyclic structure refers to a structural unit containing a cyclic structure such as an aromatic ring or an alicyclic ring. It is preferable that a structural unit having a cyclic structure contains either an aromatic ring or an alicyclic ring.

[0088] Specific examples of the polyamide resin according to the third embodiment include the following: It goes without saying that the polyamide resin according to the third embodiment is not limited to the following. (1) 80 to 97 mol% (preferably 84 to 97 mol%) of the diamine-derived structural units are derived from p-benzenediethaneamine, 3 to 20 mol% (preferably 3 to 16 mol%) are derived from the diamine represented by formula (1-1), and 90 to 100 mol% (preferably 95 to 100 mol%, more preferably 98 to 100 mol%) of the dicarboxylic acid-derived structural units are derived from isophthalic acid. (2) 70 to 80 mol% of the diamine-derived structural units are derived from p-benzenediethaneamine, 20 to 30 mol% are derived from the diamine represented by formula (1-1), and 90 to 100 mol% (preferably 95 to 100 mol%, more preferably 98 to 100 mol%) of the dicarboxylic acid-derived structural units are derived from terephthalic acid, and 0 to 10 mol% are derived from 1,4-cyclohexanedicarboxylic acid. In the above (1) and (2), the total of the constitutional units derived from p-benzenediethaneamine and the constitutional units derived from the diamine represented by formula (1-1) is 100 mol % or less, preferably 95 to 100 mol %, and more preferably 98 to 100 mol %.

[0089] The polyamide resin of the third embodiment is composed of dicarboxylic acid-derived structural units and diamine-derived structural units, but may also contain structural units other than the dicarboxylic acid-derived structural units and diamine-derived structural units, as well as other moieties such as terminal groups. Examples of other structural units include, but are not limited to, structural units derived from lactams such as ε-caprolactam, valerolactam, laurolactam, and undecalactam, and structural units derived from aminocarboxylic acids such as 11-aminoundecanoic acid and 12-aminododecanoic acid. Furthermore, the polyamide resin of this embodiment may contain trace components such as additives used in the synthesis. The polyamide resin of the third embodiment preferably comprises at least 70% by weight, more preferably at least 80% by weight, even more preferably at least 90% by weight, even more preferably at least 95% by weight, and even more preferably at least 98% by weight of dicarboxylic acid-derived structural units and diamine-derived structural units.

[0090] The polyamide resin of the fourth embodiment is composed of diamine-derived structural units and dicarboxylic acid-derived structural units, and more than 30 mol % of the diamine-derived structural units are derived from a diamine represented by formula (1-1), and more than 30 mol % of the dicarboxylic acid-derived structural units are derived from an aromatic dicarboxylic acid. (In formula (1-1), R １１ ~R １８ each independently represents a hydrogen atom or an aliphatic group having 1 to 5 carbon atoms; R １１ ~R １４ and at least one of R １５ ~R １８ At least one of the groups is an aliphatic group having 1 to 5 carbon atoms.

[0091] The diamine represented by formula (1-1) in the fourth embodiment has the same meaning as the diamine represented by formula (1-1) in the third embodiment, and the preferred range is also the same.

[0092] In the fourth embodiment, the diamine-derived structural unit may contain a structural unit other than the structural unit derived from the diamine represented by formula (1-1). Examples of such other structural units include p-benzenediethaneamine, m-benzenediethaneamine, o-benzenediethaneamine, aliphatic diamines, alicyclic diamines, and structural units derived from aromatic diamines other than benzenediethaneamine and the diamine represented by formula (1-1). From the viewpoints of high rigidity and flame retardancy, p-benzenediethaneamine is preferred.

[0093] The aliphatic diamines, alicyclic diamines, and other aromatic diamines have the same meanings as the aliphatic diamines, alicyclic diamines, and other aromatic diamines described in the section on the polyamide resin of the first embodiment, and the preferred ranges are also the same.

[0094] In a fourth embodiment, it is preferable that more than 30 mol% and 100 mol% or less of the diamine-derived structural units are derived from the diamine represented by formula (1-1), and 70 mol% to 0 mol% are derived from p-benzenediethaneamine; it is more preferable that more than 30 mol% and 100 mol% or less of the diamine-derived structural units are derived from the diamine represented by formula (1-1), and 70 mol% to 0 mol% are derived from p-benzenediethaneamine; and it is more preferable that 90 mol% or more (preferably 95 mol% or more, more preferably 99 mol% or more, and preferably 100 mol% or less) of the diamine-derived structural units are derived from the diamine represented by formula (1-1) or p-benzenediethaneamine. By adopting such a configuration, it is possible to further improve low water absorbency, high Tg, and high rigidity in a balanced manner.

[0095] The polyamide resin of the fourth embodiment may contain only one type of structural unit derived from another diamine, or may contain two or more types.

[0096] In the polyamide resin of the fourth embodiment, more than 30 mol% of the dicarboxylic acid-derived structural units are derived from aromatic dicarboxylic acids. By including structural units derived from aromatic dicarboxylic acids, a polyamide resin with a higher glass transition temperature tends to be obtained. In this embodiment, the proportion of structural units derived from aromatic dicarboxylic acids in the dicarboxylic acid-derived structural units is more than 30 mol%, preferably 40 mol% or more, more preferably 45 mol% or more, even more preferably 55 mol% or more, even more preferably more than 60 mol%, even more preferably 80 mol% or more, even more preferably 90 mol% or more, particularly preferably 95 mol% or more, and even more particularly preferably 99 mol% or more. By setting the proportion at or above the lower limit, strength during high-temperature molding tends to be improved. In this embodiment, the upper limit of the proportion of structural units derived from aromatic dicarboxylic acids in the dicarboxylic acid-derived structural units is 100 mol% or less.

[0097] The details of the aromatic dicarboxylic acid in the fourth embodiment are the same as those described in the section on the aromatic dicarboxylic acid in the first embodiment, and the preferred ranges are also the same.

[0098] In the polyamide resin of the fourth embodiment, the proportion of aromatic dicarboxylic acid-derived structural units selected from isophthalic acid, terephthalic acid, and phenylene diacetic acid (preferably isophthalic acid) in the aromatic dicarboxylic acid-derived structural units is preferably more than 30 mol%, more preferably 40 mol% or more, even more preferably 45 mol% or more, even more preferably 55 mol% or more, even more preferably more than 60 mol%, even more preferably 80 mol% or more, particularly more preferably 90 mol% or more, even more particularly more preferably 95 mol% or more, and most preferably 99 mol% or more. The upper limit is 100 mol% or less.

[0099] The polyamide resin of the fourth embodiment may contain a dicarboxylic acid-derived structural unit other than the aromatic dicarboxylic acid-derived structural unit. Examples of dicarboxylic acids constituting the dicarboxylic acid-derived structural unit other than the aromatic dicarboxylic acid-derived structural unit include aliphatic dicarboxylic acids. Examples of the aliphatic carboxylic acid include those having 2 to 20 carbon atoms, preferably 4 to 18 carbon atoms, and more preferably 8 to 14 carbon atoms. Specific examples of the aliphatic dicarboxylic acid include succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, and dodecanedioic acid, with sebacic acid and dodecanedioic acid being preferred, and dodecanedioic acid being more preferred.

[0100] When the polyamide resin of the fourth embodiment contains aliphatic dicarboxylic acid-derived structural units, the proportion thereof is preferably 60 mol% or less, more preferably 55 mol% or less, even more preferably 45 mol% or less, even more preferably 40 mol% or less, even more preferably 20 mol% or less, and even more preferably 10 mol% or less of the total dicarboxylic acid-derived structural units. When the polyamide resin of the fourth embodiment contains aliphatic dicarboxylic acid-derived structural units, the lower limit of the proportion thereof is, for example, more than 5 mol%. Furthermore, the polyamide resin of the fourth embodiment can be configured to be substantially free of aliphatic dicarboxylic acid-derived structural units. "Substantially free" means that the proportion of aliphatic dicarboxylic acid-derived structural units among the dicarboxylic acid-derived structural units is 5 mol% or less, preferably 3 mol% or less, and more preferably 1 mol% or less. Only one type of aliphatic dicarboxylic acid-derived structural unit may be contained, or two or more types may be contained.

[0101] Specific examples of the polyamide resin of the fourth embodiment include the following. It goes without saying that the polyamide resin of the fourth embodiment is not limited to the following. (1) A polyamide resin in which more than 30 mol % and 100 mol % or less of the diamine-derived structural units are derived from a diamine represented by formula (1-1), 70 mol % to 0 mol % are derived from p-benzenediethaneamine, and more than 30 mol % of the dicarboxylic acid-derived structural units are derived from an aromatic dicarboxylic acid (preferably isophthalic acid). (2) A polyamide resin in which more than 30 mol % of the diamine-derived structural units are derived from a diamine represented by formula (1-1), more than 30 mol % and 100 mol % or less of the dicarboxylic acid-derived structural units are derived from an aromatic dicarboxylic acid (preferably isophthalic acid), and 70 mol % to 0 mol % are derived from an aliphatic dicarboxylic acid (preferably dodecanedioic acid). (3) More than 30 mol% and 100 mol% or less of the diamine-derived structural units are derived from the diamine represented by formula (1-1), 70 mol% to 0 mol% are derived from p-benzenediethaneamine, and more than 30 mol% and 100 mol% or less of the dicarboxylic acid-derived structural units are derived from aromatic dicarboxylic acids (preferably isophthalic acid), and 70 mol% to 0 mol% are derived from aliphatic dicarboxylic acids (preferably dodecanedioic acid). (4) More than 30 mol% and 100 mol% or less of the diamine-derived structural units are derived from the diamine represented by formula (1-1), 70 mol% to 0 mol% are derived from p-benzenediethaneamine, and 55 mol% to 100 mol% of the dicarboxylic acid-derived structural units are derived from aromatic dicarboxylic acids (preferably isophthalic acid). Polyamide resin. In the above (1) to (4), the total of the structural units derived from the diamine represented by formula (1-1) and the structural units derived from p-benzenediethaneamine is 100 mol % or less, preferably 95 to 100 mol %, and more preferably 98 to 100 mol %. Furthermore, the total of the structural units derived from an aromatic dicarboxylic acid (preferably isophthalic acid) and the structural units derived from an aliphatic dicarboxylic acid (preferably dodecanedioic acid) is 100 mol % or less, preferably 95 to 100 mol %, and more preferably 98 to 100 mol %.

[0102] The polyamide resin of the fourth embodiment is composed of dicarboxylic acid-derived structural units and diamine-derived structural units, but may also contain structural units other than the dicarboxylic acid-derived structural units and diamine-derived structural units, as well as other moieties such as terminal groups. Examples of other structural units include, but are not limited to, lactams such as ε-caprolactam, valerolactam, laurolactam, and undecalactam, and structural units derived from aminocarboxylic acids such as 11-aminoundecanoic acid and 12-aminododecanoic acid. Furthermore, the polyamide resin of the fourth embodiment may contain trace components such as additives used in the synthesis. The polyamide resin of the fourth embodiment preferably comprises 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, and even more preferably 98% by mass or more of dicarboxylic acid-derived structural units and diamine-derived structural units.

[0103] The polyamide resin of the fifth embodiment contains diamine-derived structural units and dicarboxylic acid-derived structural units, in which 50 mol % or more of the diamine-derived structural units are derived from a compound represented by formula (1-2), and more than 50 mol % of the dicarboxylic acid structural units are derived from an aromatic dicarboxylic acid. (In formula (1-2), R ２１ ~R ２８ each independently represents a hydrogen atom or an aliphatic group having 1 to 5 carbon atoms.

[0104] In formula (1-2), R ２１ ~R ２８ each independently represents a hydrogen atom or an aliphatic group having 1 to 5 carbon atoms; R ２１ ~R ２８ are hydrogen atoms or R ２１ ~R ２４ and at least one of R ２５ ~R ２８ It is preferable that at least one of R is an aliphatic group having 1 to 5 carbon atoms. ２１ ~R ２８are more preferably hydrogen atoms. The aliphatic group having 1 to 5 carbon atoms is preferably an aliphatic group having 1 to 3 carbon atoms, and more preferably an aliphatic group having 1 or 2 carbon atoms. Examples of the aliphatic group include an alkyl group, an alkenyl group, and an alkynyl group, with an alkyl group being preferred, and a straight-chain alkyl group being more preferred. Examples of the alkyl group include a methyl group, an ethyl group, an i-propyl group, an i-butyl group, and a t-butyl group, with a methyl group and an ethyl group being preferred, and a methyl group being more preferred. The compound represented by formula (1-2) preferably contains p-benzenedipropaneamine.

[0105] In a fifth embodiment, the compound represented by formula (1-2) is derived from p-benzenedipropanamine in an amount of 70 to 100 mol %, and is a compound represented by formula (1-2) in an amount of 0 to 30 mol %, and R ２１ ~R ２８ At least one of the groups is an aliphatic group having 1 to 5 carbon atoms (preferably, R ２１ ~R ２４ and at least one of R ２５ ~R ２８ At least one of R is an aliphatic group having 1 to 5 carbon atoms, and more preferably R ２１ ~R ２４ and at least one of R ２５ ~R ２８ at least one of R is a methyl group), of which 90 to 100 mol % is derived from p-benzenedipropanamine and 0 to 10 mol % is a compound represented by formula (1-2), ２１ ~R ２８ It is more preferable that at least one of R is an aliphatic group having 1 to 5 carbon atoms, 95 to 100 mol % of which is derived from p-benzenedipropanamine, and 0 to 5 mol % of which is a compound represented by formula (1-2), ２１ ~R ２８ It is more preferable that at least one of R is an aliphatic group having 1 to 5 carbon atoms, and 99 to 100 mol % of the aliphatic group is derived from p-benzenedipropanamine, and 0 to 1 mol % of the aliphatic group is a compound represented by formula (1-2), ２１ ~R ２８It is more preferable that at least one of the groups is an aliphatic group having 1 to 5 carbon atoms. In the fifth embodiment, by using a compound represented by formula (1-2) substituted with an aliphatic group having 1 to 5 carbon atoms, it is presumed that the melting point can be lowered to some extent and the mass loss rate at temperatures slightly higher than the melting point can be reduced by inhibiting hydrogen bonding between amide groups and stacking of aromatic rings without significantly changing the distance between amide groups in the molecular chain. As a result, it is presumed that the effect of improving thermal stability during molding processing can be more effectively exerted.

[0106] In a fifth embodiment, the proportion of the structural units derived from the compound represented by formula (1-2) (preferably, p-benzenedipropanamine) in the diamine-derived structural units is 50 mol% or more, preferably greater than 57 mol%, more preferably 60 mol% or more, even more preferably 70 mol% or more, even more preferably 80 mol% or more, even more preferably 90 mol% or more, even more preferably 95 mol% or more, and particularly preferably 99 mol% or more. By setting the proportion at or above the lower limit, mechanical properties at high temperatures tend to be more excellent. Furthermore, in the fifth embodiment, the upper limit of the proportion of the structural units derived from the compound represented by formula (1-2) (preferably, p-benzenedipropanamine) in the diamine-derived structural units is 100 mol% or less. In the fifth embodiment, the compound represented by formula (1-2) in the diamine-derived structural units may be one type, or two or more types, as described above. When two or more types are included, it is preferable that the total amount be within the above range.

[0107] In the fifth embodiment, the diamine-derived structural unit may contain other structural units than those described above. Examples of such other structural units include aliphatic diamines, alicyclic diamines, and structural units derived from aromatic diamines other than benzenediethaneamine and the diamine represented by formula (1-2). The polyamide resin of the fifth embodiment may contain only one type of other diamine-derived structural unit, or may contain two or more types.

[0108] The aliphatic diamines, alicyclic diamines, and other aromatic diamines have the same meanings as the aliphatic diamines, alicyclic diamines, and other aromatic diamines described in the section on the polyamide resin of the first embodiment, and the preferred ranges are also the same.

[0109] In the polyamide resin of the fifth embodiment, more than 50 mol% of the dicarboxylic acid-derived structural units are derived from aromatic dicarboxylic acids. By including structural units derived from aromatic dicarboxylic acids, polyamide resins with higher melting points and higher glass transition temperatures tend to be obtained. In the fifth embodiment, the proportion of structural units derived from aromatic dicarboxylic acids in the dicarboxylic acid-derived structural units is more than 50 mol%, preferably 70 mol% or more, more preferably 80 mol% or more, even more preferably 90 mol% or more, even more preferably 95 mol% or more, and even more preferably 99 mol% or more. By setting the proportion at or above the lower limit, the crystallinity of the polyamide resin tends to be improved, and the crystallinity of the molded product and the strength when molded at high temperatures tend to be improved. In the fifth embodiment, the upper limit of the proportion of structural units derived from aromatic dicarboxylic acids in the dicarboxylic acid-derived structural units is 100 mol% or less.

[0110] A preferred example of the aromatic dicarboxylic acid in the fifth embodiment is p-aromatic dicarboxylic acid. Increasing the proportion of p-aromatic dicarboxylic acid can enhance the crystallinity of the resulting polyamide resin. p-Aromatic dicarboxylic acid refers to a dicarboxylic acid in which two carboxyl groups or substituents containing carboxyl groups are bonded to a benzene ring in a para-position relationship. Examples include terephthalic acid and p-phenylene diacetic acid, with terephthalic acid being preferred.

[0111] The aromatic dicarboxylic acid in the fifth embodiment may include an aromatic dicarboxylic acid other than p-aromatic dicarboxylic acid. Examples of the aromatic dicarboxylic acid other than p-aromatic dicarboxylic acid include the aromatic dicarboxylic acids described in the section on aromatic dicarboxylic acids in the first embodiment.

[0112] In the polyamide resin of the fifth embodiment, it is preferable that 90 mol% or more (preferably more than 95 mol%, more preferably 99 mol% or more) of the structural units derived from aromatic dicarboxylic acids are selected from isophthalic acid, terephthalic acid, and phenylene diacetic acid, and it is more preferable that they are structural units derived from terephthalic acid.

[0113] The polyamide resin of the fifth embodiment may contain dicarboxylic acid-derived structural units other than those derived from aromatic dicarboxylic acids. Examples of dicarboxylic acids constituting the dicarboxylic acid-derived structural units other than those derived from aromatic dicarboxylic acids include aliphatic dicarboxylic acids. Known aliphatic dicarboxylic acids can be used as the aliphatic dicarboxylic acids, and examples include succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, and dodecanedicarboxylic acid. Furthermore, the polyamide resin of the fifth embodiment may be substantially free of aliphatic dicarboxylic acid-derived structural units. "Substantially free" means that the proportion of aliphatic dicarboxylic acid-derived structural units in the dicarboxylic acid-derived structural units is 5 mol% or less, preferably 3 mol% or less, and more preferably 1 mol% or less.

[0114] Furthermore, in the polyamide resin of the fifth embodiment, it is preferable that more than 95 mol% (preferably 96 mol% or more, more preferably 98 mol% or more, and 100 mol% or less) of the diamine-derived structural units and dicarboxylic acid-derived structural units are structural units having a cyclic structure. This configuration results in a polyamide resin with a higher melting point and a higher glass transition temperature. It is also possible to reduce the mass loss rate. Furthermore, the increase in the temperature-lowering crystallization enthalpy change (ΔH(Tcc)) tends to further improve moldability. In addition, the amount of outgassing can be reduced. A structural unit having a cyclic structure refers to a structural unit containing a cyclic structure such as an aromatic ring or an alicyclic ring. It is preferable that a structural unit having a single cyclic structure (usually a structural unit formed from a single monomer) contains either an aromatic ring or an alicyclic ring.

[0115] Specific examples of the polyamide resin of the fifth embodiment include the following: It goes without saying that the polyamide resin of the fifth embodiment is not limited to the following. (1) A polyamide resin in which 70 mol% or more (preferably 90 to 100 mol%, more preferably 95 to 100 mol%, even more preferably 98 to 100 mol%) of the diamine-derived structural units are derived from p-benzenedipropanamine, and more than 70 mol% (preferably 90 to 100 mol%, more preferably 94 to 100 mol%, even more preferably 97 to 100 mol%) of the dicarboxylic acid-derived structural units are derived from terephthalic acid. (2) A polyamide resin in which 70 mol% or more (preferably 90 to 100 mol%, more preferably 95 to 100 mol%, even more preferably 98 to 100 mol%) of the diamine-derived structural units are derived from p-benzenedipropanamine, and 90 to 100 mol% (preferably 95 to 100 mol%, more preferably 98 to 100 mol%) of the dicarboxylic acid-derived structural units are derived from phenylene diacetic acid (preferably m-phenylene diacetic acid and / or p-phenylene diacetic acid, more preferably p-phenylene diacetic acid). (3) A polyamide resin in which 90 to 100 mol % (preferably 95 to 100 mol %, more preferably 98 to 100 mol %) of the diamine-derived structural units are derived from p-benzenedipropanamine, 80 to 95 mol % (preferably 85 to 95 mol %) of the dicarboxylic acid-derived structural units are derived from terephthalic acid, and 20 to 5 mol % (preferably 15 to 5 mol %) are derived from cyclohexanedicarboxylic acid (preferably 1,4-cyclohexanedicarboxylic acid).

[0116] The polyamide resin of the fifth embodiment contains dicarboxylic acid-derived structural units and diamine-derived structural units, but may also contain structural units other than the dicarboxylic acid-derived structural units and diamine-derived structural units, as well as other moieties such as terminal groups. Examples of other structural units include, but are not limited to, lactams such as ε-caprolactam, valerolactam, laurolactam, and undecalactam, and structural units derived from aminocarboxylic acids such as 11-aminoundecanoic acid and 12-aminododecanoic acid. Furthermore, the polyamide resin of the fifth embodiment may contain trace components such as additives used in the synthesis. The polyamide resin of the fifth embodiment preferably comprises 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, and even more preferably 98% by mass or more of dicarboxylic acid-derived structural units and diamine-derived structural units.

[0117] <Applications> The polyamide resin obtained by the manufacturing method of this embodiment can be used as a resin composition containing the polyamide resin obtained by the manufacturing method of this embodiment. Furthermore, the above-described polyamide resin can be used as a resin composition containing the polyamide resin, regardless of the manufacturing method. Furthermore, these resin compositions can be used as molded articles. The resin composition may contain only one or more of the above-described polyamide resins, or may contain other components. Other components include polyamide resins other than the above-described polyamide resins, thermoplastic resins other than polyamide resins, reinforcing materials, fillers, delustering agents, antioxidants such as heat stabilizers and weather stabilizers, UV absorbers, plasticizers, flame retardants, flame retardant assistants, nucleating agents, mold release agents, antistatic agents, color inhibitors, and antigelling agents, and other additives may be added as needed. Each of these additives may be one type or two or more types. For details, please refer to paragraphs 0043 to 0103 of the specification of International Application No. PCT / JP2021 / 019513, the contents of which are incorporated herein by reference.

[0118] An example of the resin composition of this embodiment is a resin composition containing a polyamide resin that contains diamine-derived structural units and dicarboxylic acid-derived structural units, in which more than 30 mol % of the diamine-derived structural units are diamine-derived structural units represented by formula (1), and 20 mol % or more of the dicarboxylic acid-derived structural units are aromatic dicarboxylic acid-derived structural units, and a reinforcing material. (In formula (1), R １ ~R ８ each independently represents a hydrogen atom or an aliphatic group having 1 to 5 carbon atoms. X1 and X2 each independently represent 1 or 2.

[0119] The resin composition of this embodiment preferably contains a reinforcing material in a proportion of 5.0 to 60.0 mass % of the resin composition. The reinforcing material that can be used in this embodiment is not particularly limited, and may be any of fibers, fillers, flakes, beads, etc., but fibers are preferred.

[0120] When the reinforcing material is a fiber, it may be a short fiber or a long fiber. When the reinforcing material is a short fiber, filler, beads, or the like, the resin composition of this embodiment may be in the form of pellets, powdered pellets, or a film formed from the pellets. When the reinforcing material is a long fiber, it may be in the form of a long fiber for a so-called UD material (unidirectional), or a sheet-like long fiber such as a woven or knitted fabric. When using these long fibers, components other than the reinforcing material of the resin composition of this embodiment may be impregnated into the sheet-like long fiber reinforcing material to form a sheet-like resin composition (e.g., a prepreg).

[0121] Examples of raw materials for the reinforcing material include inorganic substances such as glass, carbon (carbon fiber, etc.), alumina, boron, ceramic, metal (steel, etc.), asbestos, clay, zeolite, potassium titanate, barium sulfate, titanium oxide, silicon oxide, aluminum oxide, and magnesium hydroxide, and organic substances such as plants (including kenaf, bamboo, etc.), aramid, polyoxymethylene, aromatic polyamide, polyparaphenylene benzobisoxazole, and ultra-high molecular weight polyethylene, with glass being preferred.

[0122] The resin composition of this embodiment preferably contains glass fibers as a reinforcing material. The glass fibers are selected from glass compositions such as A-glass, C-glass, E-glass, R-glass, D-glass, M-glass, and S-glass, with E-glass (alkali-free glass) being particularly preferred. Glass fibers refer to fibrous materials having a circular or polygonal cross section when cut perpendicular to the longitudinal direction. The number-average fiber diameter of single fibers of glass fibers is typically 1 to 25 μm, preferably 5 to 17 μm. By setting the number-average fiber diameter to 1 μm or more, the moldability of the resin composition tends to be further improved. By setting the number-average fiber diameter to 25 μm or less, the appearance of the resulting molded product tends to be improved, and the reinforcing effect also tends to be improved. The glass fibers may be single fibers or multiple twisted single fibers. The glass fiber may be in the form of a glass roving obtained by continuously winding a single fiber or a plurality of twisted fibers, a chopped strand cut to a length of 1 to 10 mm (i.e., glass fiber having a number average fiber length of 1 to 10 mm), or a milled fiber pulverized to a length of about 10 to 500 μm (i.e., glass fiber having a number average fiber length of 10 to 500 μm). However, chopped strands cut to a length of 1 to 10 mm are preferred. Glass fibers of different forms can also be used in combination. Glass fibers having an irregular cross-sectional shape are also preferred. This irregular cross-sectional shape refers to a shape in which the flatness, expressed as the ratio of the major axis to the minor axis of the cross section perpendicular to the longitudinal direction of the fiber, is, for example, 1.5 to 10, preferably 2.5 to 10, more preferably 2.5 to 8, and particularly preferably 2.5 to 5.

[0123] The glass fiber may be surface-treated with, for example, a silane-based compound, an epoxy-based compound, a urethane-based compound, or the like, or may be oxidized, in order to improve its affinity with the resin component, as long as the properties of the resin composition of this embodiment are not significantly impaired.

[0124] The reinforcing material used in this embodiment may be a conductive reinforcing material. Specific examples include metals, metal oxides, conductive carbon compounds, and conductive polymers, with conductive carbon compounds being preferred. Metals include copper, nickel, silver, and stainless steel, with metal fillers, stainless steel fibers, and magnetic fillers being preferred. Metal oxides include alumina and zinc oxide, with alumina fibers and zinc oxide nanotubes being preferred. Conductive carbon compounds include carbon black, ketjen carbon, graphene, graphite, fullerenes, carbon nanocoils, carbon nanotubes, and carbon fibers, with carbon nanotubes being more preferred. Fibers coated with metals, metal oxides, or conductive carbon compounds are also preferred. Examples include carbon-coated potassium titanate whiskers and metal-coated fibers. For other reinforcing materials, the disclosures in paragraphs 0033 to 0041 of JP 2021-031633 A can be referenced, the contents of which are incorporated herein by reference.

[0125] When the resin composition of this embodiment contains a reinforcing material (preferably glass fiber), the content thereof is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, even more preferably 30 parts by mass or more, and even more preferably 40 parts by mass or more, relative to 100 parts by mass of polyamide resin. By setting the content at or above the lower limit, the mechanical strength of the obtained molded body tends to be further increased. Furthermore, the content of the reinforcing material (preferably glass fiber) is preferably 100 parts by mass or less, more preferably 90 parts by mass or less, even more preferably 85 parts by mass or less, even more preferably 80 parts by mass or less, and even more preferably 75 parts by mass or less, relative to 100 parts by mass of polyamide resin. By setting the content at or below the upper limit, the appearance of the molded body tends to be improved, and the fluidity of the resin composition tends to be further improved. The resin composition of this embodiment may contain only one type of reinforcing material (preferably glass fiber), or may contain two or more types. When two or more types are contained, the total amount is preferably within the above range.

[0126] <Molded Article> A molded article is formed from the polyamide resin obtained by the manufacturing method of this embodiment or the resin composition of this embodiment. The method for molding the molded article is not particularly limited, and conventionally known molding methods can be used, such as injection molding, injection compression molding, extrusion molding, profile extrusion, transfer molding, blow molding, gas-assisted blow molding, blow molding, extrusion blow molding, IMC (in-mold coating molding), rotational molding, multilayer molding, two-color molding, insert molding, sandwich molding, foam molding, pressure molding, stretching, vacuum molding, etc. Examples of molded articles formed from the composition of this embodiment include injection molded articles, thin-walled molded articles, hollow molded articles, films (including plate-shaped and sheet-shaped), cylindrical (hoses, tubes, etc.), annular, circular, elliptical, gear-shaped, polygonal, irregular-shaped, hollow, frame-shaped, box-shaped, panel-shaped extrusion molded articles, fibers, etc.

[0127] The polyamide resin or polyamide resin composition obtained by the production method of this embodiment is further preferably used as the following materials: a prepreg obtained by impregnating the polyamide resin or polyamide resin composition obtained by the production method of this embodiment into the above-mentioned reinforcing material (particularly a reinforcing material, preferably carbon fiber or glass fiber); a mixed yarn, braided cord, or twisted cord containing, as fiber components, continuous thermoplastic resin fibers containing the polyamide resin or polyamide resin composition obtained by the production method of this embodiment and a continuous reinforcing material; a woven or knitted fabric using continuous thermoplastic resin fibers containing the polyamide resin or polyamide resin composition obtained by the production method of this embodiment and a continuous reinforcing material; and a nonwoven fabric composed of thermoplastic resin fibers containing the polyamide resin or polyamide resin composition obtained by the production method of this embodiment and a reinforcing material.

[0128] Molded products include films, sheets, tubes, pipes, gears, cams, various housings, rollers, impellers, bearing retainers, spring holders, clutch parts, chain tensioners, tanks, wheels, connectors, switches, sensors, sockets, capacitors, hard disk parts, jacks, fuse holders, relays, coil bobbins, resistors, IC housings, LED reflectors, intake pipes, blow-by tubes, 3D printer substrates, automotive interior and exterior parts, engine compartment parts, cooling system parts, sliding parts, automotive supplies such as electrical parts and electronic parts, surface-mounted connectors, sockets, camera modules, power supply parts, switches, sensors, capacitor base plates, hard disk parts, relays, resistors, fuse holders, coil bobbins, IC housings, and other surface-mounted parts, fuel caps, fuel tanks, fuel sender modules, fuel cut-off valves, canisters, and fuel pipes. Specifically, the fuel system parts can be suitably used in various devices equipped with engines that use fuels such as gasoline, diesel, etc., such as automobiles, tractors, cultivators, brush cutters, lawn mowers, chainsaws, etc. For details of the fuel system parts, please refer to paragraphs 0057 to 0061 of WO 2012 / 098840, the contents of which are incorporated herein by reference.

[0129] The present invention will be explained in more detail below with reference to examples. The materials, amounts used, ratios, treatment contents, treatment procedures, etc. shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below. If the measuring instruments used in the examples are difficult to obtain due to discontinuation or the like, measurements can be made using other instruments with equivalent performance.

[0130] <Raw Materials> p-BDEA: p-benzenediethaneamine, synthesized according to the following synthesis example. <<Synthesis Example of p-BDEA>> p-xylylene dicyanide (manufactured by Tokyo Chemical Industry Co., Ltd.) was reduced under a hydrogen atmosphere, and the resulting product was purified by distillation to obtain p-benzenediethaneamine. Analysis using gas chromatography revealed that the purity was 99.7%.

[0131] p-BDEA-4Me: Organic synthesis was performed according to the description in Example 3 of JP-T-2004-503527. The resulting hydrochloride salt of p-BDEA-4Me was neutralized, and p-BDEA-4Me was extracted. The resulting extract was purified by distillation to obtain the following compound. Analysis by gas chromatography revealed that the purity was 99.7%.

[0132] p-BDPA: p-benzenedipropanamine was synthesized according to the following synthesis example. <<Synthesis Example of p-BDPA>> 10 g of p-phenyldipropionitrile, 0.3 g of Raney-Ni, and 40 mL of ethanol were charged into an autoclave, and hydrogen gas was continuously supplied so that the pressure in the reactor was constant at 8 MPa, and the reaction was carried out at 110°C for 1.5 hours. The reactor was cooled to room temperature, and the hydrogen gas inside the reactor was released. The contents were filtered and purified by distillation to obtain p-benzenedipropanamine. Analysis using gas chromatography revealed that the purity was 99.3%.

[0133] Isophthalic acid: manufactured by Tokyo Chemical Industry Co., Ltd. Terephthalic acid: manufactured by Tokyo Chemical Industry Co., Ltd. 1,4-CHDA: t-1,4-cyclohexanedicarboxylic acid, manufactured by Tokyo Chemical Industry Co., Ltd. Sebacic acid: manufactured by Tokyo Chemical Industry Co., Ltd.

[0134] <Weight average molecular weight (Mw) and number average molecular weight (Mn) of polyamide resin> The weight average molecular weight (Mw) and number average molecular weight (Mn) of the polyamide resin were measured by gel permeation chromatography (GPC) using standard polymethyl methacrylate (PMMA) equivalent values. Two columns packed with a styrene polymer were used as the filler, and hexafluoroisopropanol (HFIP) with a sodium trifluoroacetate concentration of 2 mmol / L was used as the solvent. The resin concentration was 0.02% by mass, the column temperature was 40 ° C, the flow rate was 0.3 mL / min, and the measurement was performed using a refractive index detector (RI). In addition, a calibration curve was measured by dissolving six levels of PMMA in HFIP. In addition, Mw / Mn was calculated from the weight average molecular weight (Mw) and number average molecular weight (Mn) measured above.

[0135] Example 1 4,552 g (27.4 mol) of isophthalic acid, 524 g (3.0 mol) of 1,4-cyclohexanedicarboxylic acid, 5,000 g (30.4 mol) of p-benzenediethaneamine, 1.48 g (0.0087 mol) of calcium hypophosphite, sodium acetate (0.0116 mol), and 5,240 g of water (added so as to provide 34% by mass of the total amount of substances present in the polymerization reaction system) were placed in a 50 L reactor, purged with nitrogen, and heating was initiated with stirring. The internal temperature was raised to 160°C over one hour. Stirring was performed using a double helical ribbon impeller, and the gap between the impeller shaft and the reactor top was sealed with purified water as a sealing liquid. The details of the reaction conditions for the early polycondensation step are shown in Table 1. The internal temperature was then raised to 200°C, and 3,600 g of water was distilled off over three hours (water content after water removal: 24% by mass). The details of the reaction conditions for the water removal step are shown in Table 1. Subsequently, the internal temperature was raised to 210°C and maintained for 1 hour. Thereafter, a primary polycondensation product was obtained by flashing from the outlet at the bottom of the reaction vessel. Details of the reaction conditions for the later polycondensation step are shown in Table 1. Next, the obtained primary polycondensation product was subjected to solid-state polymerization to achieve a high degree of polymerization. At this time, the solid-state polymerization was carried out using an inert oven by heating at 260°C for 2 hours under a nitrogen atmosphere. The molecular weights of the primary polycondensation product obtained by synthesis and the polyamide resin obtained after solid-state polymerization are shown in Table 1.

[0136] Examples 2 to 8 The same procedures as in Example 1 were carried out except that the raw material monomers and the like were changed as shown in Table 1.

[0137]

[0138] Example 9: Four parts by mass of a nucleating agent (Micron White 5000S, manufactured by Hayashi Kasei Co., Ltd.) was weighed out and dry-blended relative to 100 parts by mass of the polyamide resin obtained in Example 1. The mixture was then introduced into a twin-screw extruder (TEM26SX, manufactured by Shibaura Machine Co., Ltd.) from the base of the screw using a twin-screw cassette weighing feeder (CE-W-1-MP, manufactured by Kubota Corporation). Glass fiber (40 parts by mass per 100 parts by mass of polyamide resin, T-756H, manufactured by Nippon Electric Glass Co., Ltd.) was introduced into the twin-screw extruder from the side using a vibrating cassette weighing feeder (CE-V-1B-MP, manufactured by Kubota Corporation), and melt-kneaded with the resin components to obtain resin composition pellets. The extruder temperature was set to 320°C. The same procedure was repeated for the polyamide resins obtained in Examples 2 to 8.

[0139] The resin composition pellets obtained above were dried at 160° C. for 4 hours, and then test specimens were prepared using an injection molding machine (SE-130DU, manufactured by Sumitomo Heavy Industries, Ltd.).

Claims

1. Polycondensing a diamine and a dicarboxylic acid in the presence of water to obtain a primary polycondensate; The primary polycondensate is polymerized to a high degree, More than 30 mol% of the diamine is a diamine represented by formula (1), 20 mol% or more of the dicarboxylic acids are aromatic dicarboxylic acids; A method for producing polyamide resin. Formula (1) 【Chemical 1】 (In formula (1), R １ ~R ８ each independently represents a hydrogen atom or an aliphatic group having 1 to 5 carbon atoms. X1 and X2 each independently represent 1 or 2.

2. The method according to claim 1, wherein the stirring in the polycondensation is performed using a stirring blade, and a sealing liquid is placed between the shaft of the stirring blade and the top plate of the reaction vessel to seal the space.

3. The method according to claim 1 or 2, comprising adding the diamine and the dicarboxylic acid simultaneously to a polycondensation reaction system.

4. 3. The method according to claim 1, wherein the amount of water added to the polycondensation reaction system is 28 to 80% by mass based on the total amount of substances present in the polycondensation reaction system.

5. The production method according to claim 1 or 2, further comprising removing a portion of the water from the polycondensation reaction system and allowing the polycondensation to proceed further.

6. The method according to claim 1 or 2, wherein the primary polycondensate is polymerized to a high degree by solid-state polymerization.

7. The polyamide resin is composed of diamine-derived structural units and dicarboxylic acid-derived structural units, and 50 mol% or more of the diamine-derived structural units are p-benzenediethaneamine-derived structural units, and 65 mol% or more of the dicarboxylic acid-derived structural units are aromatic dicarboxylic acid-derived structural units.

8. The method according to claim 7, wherein 65 to 97 mol % of the dicarboxylic acid-derived structural units are aromatic dicarboxylic acid-derived structural units and 3 to 35 mol % of the dicarboxylic acid-derived structural units are alicyclic dicarboxylic acid-derived structural units.

9. The method according to claim 1, wherein the polyamide resin is composed of diamine-derived structural units and dicarboxylic acid-derived structural units, and 50 mol% or more of the diamine-derived structural units are structural units derived from p-benzenediethaneamine, 20 mol% or more but less than 95 mol% of the dicarboxylic acid structural units are structural units derived from aromatic dicarboxylic acid, and more than 5 mol% but 80 mol% or less are structural units derived from α,ω-linear aliphatic dicarboxylic acid having 4 to 15 carbon atoms.

10. The method according to claim 9, wherein more than 5 mol % and not more than 80 mol % of the dicarboxylic acid constituent units are constituent units derived from a dicarboxylic acid selected from adipic acid and sebacic acid.

11. The production method according to claim 9, wherein 40 to 90 mol % of the dicarboxylic acid-derived structural units are aromatic dicarboxylic acid-derived structural units and 10 to 60 mol % are C4 to C15 linear α,ω-aliphatic dicarboxylic acid-derived structural units.

12. the polyamide resin is composed of a diamine-derived structural unit and a dicarboxylic acid-derived structural unit, 70 to 97 mol % of the diamine-derived structural units are derived from p-benzenediethaneamine, and 3 to 30 mol % are derived from a diamine represented by formula (1-1), 50 mol % or more of the dicarboxylic acid-derived structural units are derived from aromatic dicarboxylic acids, The method of claim 1. Formula (1-1) 【Chemistry 2】 (In formula (1-1), R １１ ~R １８ each independently represents a hydrogen atom or an aliphatic group having 1 to 5 carbon atoms; R １１ ~R １４ and at least one of R １５ ~R １８ At least one of the groups is an aliphatic group having 1 to 5 carbon atoms.

13. the polyamide resin is composed of diamine-derived structural units and dicarboxylic acid-derived structural units, more than 30 mol% of the diamine-derived structural units are derived from a diamine represented by formula (1-1), and more than 30 mol% of the dicarboxylic acid-derived structural units are derived from an aromatic dicarboxylic acid; The method of claim 1. Formula (1-1) 【Chemistry 3】 (In formula (1-1), R １１ ~R １８ each independently represents a hydrogen atom or an aliphatic group having 1 to 5 carbon atoms; R １１ ~R １４ and at least one of R １５ ~R １８ At least one of the groups is an aliphatic group having 1 to 5 carbon atoms.

14. the polyamide resin contains diamine-derived structural units and dicarboxylic acid-derived structural units, 50 mol % or more of the diamine-derived structural units are derived from a compound represented by formula (1-2), and more than 50 mol % of the dicarboxylic acid structural units are derived from an aromatic dicarboxylic acid; The method of claim 1. Formula (1-2) 【Chemistry 4】 (In formula (1-2), R ２１ ~R ２８ each independently represents a hydrogen atom or an aliphatic group having 1 to 5 carbon atoms.

15. The stirring in the polycondensation is performed using a stirring blade, and a sealing liquid is placed between the shaft of the stirring blade and the top plate of the reaction vessel to seal the space between the shaft and the top plate of the reaction vessel, adding the diamine and the dicarboxylic acid simultaneously to a polycondensation reaction system; the amount of water added to the polycondensation reaction system is 28 to 80% by mass based on the total amount of substances present in the polycondensation reaction system; removing a portion of the water from the polycondensation reaction system and further promoting the polycondensation; The method according to any one of claims 7 to 14, wherein the primary polycondensate is polymerized to a high degree by solid-state polymerization.

16. A resin composition comprising a polyamide resin containing diamine-derived structural units and dicarboxylic acid-derived structural units, wherein more than 30 mol % of the diamine-derived structural units are diamine-derived structural units represented by formula (1), and 20 mol % or more of the dicarboxylic acid-derived structural units are aromatic dicarboxylic acid-derived structural units, and a reinforcing material. Formula (1) 【Chemistry 5】 (In formula (1), R １ ~R ８ each independently represents a hydrogen atom or an aliphatic group having 1 to 5 carbon atoms. X1 and X2 each independently represent 1 or 2.

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