Polyamide resin

Abstract

Provided is a polyamide resin having excellent heat-resistance, particularly a high glass transition temperature. This polyamide resin comprises a structural unit derived from a diamine and a structural unit derived from a dicarboxylic acid, wherein not less than 50 mol% of the structural unit derived from a diamine is derived from a compound represented by formula (1), and more than 50 mol% of the structural unit derived from a dicarboxylic acid is derived from an aromatic dicarboxylic acid. In formula (1), R1-R8 each independently represent a hydrogen atom or an aliphatic group having 1-5 carbon atoms.

Description

[Technical Field]

[0001] The present invention relates to a polyamide resin. [Background technology]

[0002] Polyamide resins are widely used as various industrial materials due to their excellent processability, durability, heat resistance, gas barrier properties, chemical resistance, and the like. 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, have also come into use. Such aromatic polyamide resins are described, for example, in Patent Documents 1 and 2. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 62-054725 [Patent Document 2] Japanese Patent Application Publication No. 08-003312 Summary of the Invention [Problem to be solved by the invention]

[0004] As mentioned above, polyamide resins are widely used in various fields. Among them, along with technological innovation, there is a demand for polyamide resins with excellent heat resistance. In particular, there is a demand for polyamide resins with high glass transition temperatures. The present invention has an object to solve the above problems, and an object of the present invention is to provide a polyamide resin having excellent heat resistance, particularly a high glass transition temperature. [Means for solving the problem]

[0005] In light of the above problems, the present inventors have conducted research and found that the above problems can be solved by synthesizing a polyamide resin using a predetermined aromatic diamine and aromatic dicarboxylic acid. Specifically, the above problems were solved by the following means. <1> A polyamide resin comprising diamine-derived structural units and dicarboxylic acid-derived structural units, wherein 50 mol % or more of the diamine-derived structural units are derived from a compound represented by formula (1), and more than 50 mol % of the dicarboxylic acid-derived structural units are derived from an aromatic dicarboxylic acid. Formula (1) [ka] (In formula (1), R 1 ~R 8 each independently represents a hydrogen atom or an aliphatic group having 1 to 5 carbon atoms. <2> The polyamide resin has an enthalpy change (ΔH) upon melting evaluated by differential scanning calorimetry of 5 to 60 J / g. <1> The polyamide resin according to claim 1. <3> The compound represented by formula (1) contains p-benzenedipropanamine. <1> or <2> The polyamide resin according to claim 1. <4> The aromatic dicarboxylic acid includes a compound represented by formula (FC1). <1> ~ <3> 1. The polyamide resin according to claim 1 . Formula (FC1) HOOC-Aromatic ring structure-COOH <5> The aromatic dicarboxylic acid includes a p-aromatic dicarboxylic acid. <1> ~ <4> 1. The polyamide resin according to claim 1 . <6> The aromatic dicarboxylic acid includes at least one selected from isophthalic acid, terephthalic acid, and phenylene diacetic acid. <1> ~ <3> 1. The polyamide resin according to claim 1 . <7> The aromatic dicarboxylic acid includes terephthalic acid. <1> ~ <3> 1. The polyamide resin according to claim 1 . <8> 70 mol% or more of the diamine-derived structural units are derived from p-benzenedipropanamine, and more than 70 mol% of the dicarboxylic acid-derived structural units are derived from terephthalic acid. <1> or <2> The polyamide resin according to claim 1. <9> The polyamide resin has a glass transition temperature of 80 to 160°C as measured by differential scanning calorimetry. <1> ~ <8> 1. The polyamide resin according to claim 1 . <10> the mass loss rate after heating for 30 minutes at a temperature of the melting point of the polyamide resin according to differential scanning calorimetry + 25°C is 4.0% or less; <1> ~ <9> 1. The polyamide resin according to claim 1 . [Effects of the Invention]

[0006] According to the present invention, a polyamide resin having excellent heat resistance, particularly a high glass transition temperature, can be obtained. DETAILED DESCRIPTION OF THE INVENTION

[0007] Hereinafter, an embodiment for carrying out the present invention (hereinafter simply referred to as "the present embodiment") will be described in detail. Note that the present embodiment is an example for explaining the present invention, and the present invention is not limited to only this embodiment. In this specification, the symbol "to" is used to mean that the numerical values ​​before and after it are included as the lower limit and upper limit. In this specification, various physical properties and characteristic values ​​are those at 23°C unless otherwise specified. If the standards shown in this specification differ depending on the year and the measurement method, etc., they will be based on the standards as of January 1, 2021, unless otherwise stated.

[0008] The polyamide resin of the present embodiment contains diamine-derived structural units and dicarboxylic acid-derived structural units, and is characterized in that 50 mol % or more of the diamine-derived structural units are derived from a compound represented by formula (1), and more than 50 mol % of the dicarboxylic acid-derived structural units are derived from an aromatic dicarboxylic acid. This configuration allows for the production of polyamide resins with excellent heat resistance, particularly a high glass transition temperature. Furthermore, the polyamide resins of this embodiment have a small temperature difference between the melting point and the crystallization temperature (Tm-Tcc), and tend to have excellent moldability. Furthermore, the polyamide resins of this embodiment tend to have excellent heat aging resistance. The reason for this is presumably that the compound represented by formula (1) is used as the diamine. That is, by providing an alkylene group between the benzene ring and the amino group, a polyamide resin with excellent heat resistance and other properties can be obtained.

[0009] <Diamine-derived structural units> In the polyamide resin of this embodiment, 50 mol % or more of the diamine-derived structural units are derived from the compound represented by formula (1). By using the compound represented by formula (1), a polyamide resin having excellent heat resistance, particularly a high glass transition temperature Tg, can be obtained. [ka] (In formula (1), R 1 ~R 8 each independently represents a hydrogen atom or an aliphatic group having 1 to 5 carbon atoms.

[0010] In formula (1), R 1 ~R 8 each independently represents a hydrogen atom or an aliphatic group having 1 to 5 carbon atoms, and R 1 ~R 8 are hydrogen atoms or R 1 ~R 4 At least one of and R 5 ~R 8 It is preferable that at least one of R is an aliphatic group having 1 to 5 carbon atoms. 1 ~R 8 It is more preferable that all of the above are hydrogen atoms. The aliphatic group having 1 to 5 carbon atoms is preferably an aliphatic group having 1 to 3 carbon atoms, 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) preferably contains p-benzenedipropanamine.

[0011] In this embodiment, the compound represented by formula (1) is derived from p-benzenedipropanamine in an amount of 70 to 100 mol %, and is a compound represented by formula (1) in an amount of 0 to 30 mol %, and R 1 ~R 8 At least one of the groups is an aliphatic group having 1 to 5 carbon atoms (preferably, R 1 ~R 4 At least one of and R 5 ~R 8 At least one of R is an aliphatic group having 1 to 5 carbon atoms, and more preferably R 1 ~R 4 At least one of and R 5 ~R 8 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), 1 ~R 8 It is more preferable that at least one of R is an aliphatic group having 1 to 5 carbon atoms, and 95 to 100 mol % of the aliphatic group is derived from p-benzenedipropanamine and 0 to 5 mol % is a compound represented by formula (1), 1 ~R 8 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 % is a compound represented by formula (1), 1 ~R 8 It is more preferable that at least one of them is an aliphatic group having 1 to 5 carbon atoms. In this embodiment, by using a compound represented by formula (1) containing a substitution 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, which is presumed to result in a more effective improvement in thermal stability during molding processing.

[0012] In this embodiment, the proportion of structural units derived from the compound represented by formula (1) (preferably, p-benzenedipropanamine) in the diamine-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 95 mol% or more, and even more preferably 99 mol% or more. By ensuring that the proportion is above the above lower limit, mechanical properties at high temperatures tend to be more excellent. Furthermore, in this embodiment, the upper limit of the proportion of structural units derived from the compound represented by formula (1) (preferably, p-benzenedipropanamine) in the diamine-derived structural units is 100 mol% or less. In this embodiment, the compound represented by formula (1) in the diamine-derived structural unit may be one type, or two or more types, as described above. When two or more types are contained, the total amount is preferably in the above range.

[0013] In this embodiment, the diamine-derived structural units 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). The polyamide resin of the present embodiment may contain only one type of structural unit derived from another diamine, or may contain two or more types.

[0014] 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). For other aromatic diamines, please refer to paragraph 0052 of WO 2017 / 126409, the contents of which are incorporated herein by reference.

[0015] <Structural units derived from dicarboxylic acids> In the polyamide resin of this 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, the resulting polyamide resin tends to have a higher melting point and a higher glass transition temperature. In this embodiment, the proportion of aromatic dicarboxylic acid-derived structural units in the dicarboxylic acid-derived structural units is greater than 50 mol%, preferably 70 mol% or more, more preferably 80 mol% or more, even more preferably 90 mol% or more, even more preferably greater than 95 mol%, and even more preferably 99 mol% or more. By making the proportion equal to or greater than 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 aromatic dicarboxylic acid-derived structural units in the dicarboxylic acid-derived structural units is 100 mol% or less.

[0016] A preferred example of the aromatic dicarboxylic acid in this embodiment is p-aromatic dicarboxylic acid. Increasing the proportion of p-aromatic dicarboxylic acid can improve 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.

[0017] Another preferred example of the aromatic dicarboxylic acid in this embodiment is an aromatic dicarboxylic acid represented by formula (FC). Formula (FC) HOOC-(CH2) m -Aromatic ring structure-(CH2) m -COOH (In formula (FC), m represents 0, 1 or 2.)

[0018] m is preferably 0 or 1, and more preferably 0.

[0019] In formula (FC), each CH2 is attached to an aromatic ring. 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 on the aromatic ring, and more preferably a structure consisting of only an aromatic ring. Examples of the substituent that the aromatic ring may have include an alkyl group having 1 to 3 carbon atoms or a halogen atom. The aromatic ring structure may be either a monocyclic or condensed ring, with a monocyclic ring being preferred. The number of carbon atoms constituting the aromatic ring is not particularly limited, but a 6- to 15-membered ring is preferred. More specifically, the aromatic ring structure is preferably a benzene ring, a naphthalene ring, a substituted benzene ring, or a substituted naphthalene ring, more preferably a benzene ring or a substituted benzene ring, and even more preferably a benzene ring.

[0020] The aromatic dicarboxylic acid represented by formula (FC) preferably includes a compound represented by formula (FC1). By using a structure in which a carboxyl group is directly bonded to an aromatic ring, the glass transition temperature of the resulting polyamide resin can be increased. In addition, copolymerization with terephthalic acid can be improved. Formula (FC1) HOOC-Aromatic ring structure-COOH In formula (FC), each COOH is attached to an aromatic ring. In the above formula (FC1), the two carboxyl groups may be bonded to the aromatic ring at any of the meta, para, and ortho positions, but are preferably bonded at the meta or para positions, and more preferably at the para positions.

[0021] More specific examples of the aromatic dicarboxylic acid in this embodiment include isophthalic acid, terephthalic acid, orthophthalic acid, phenylene diacetic acid (o-phenylene diacetic acid, p-phenylene diacetic acid, m-phenylene diacetic acid), and naphthalenedicarboxylic acid (1,2-naphthalenedicarboxylic acid, 1,3-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 1,6-naphthalenedicarboxylic acid, 1,7-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, and 2,7-naphthalenedicarboxylic acid). Among these, it is preferable to select from isophthalic acid, terephthalic acid, and phenylene diacetic acid (preferably p-phenylene diacetic acid), and terephthalic acid is more preferable. By using terephthalic acid, the heat resistance (Tg, Tm) of the obtained polyamide resin is further improved. In addition, the Tm-Tcc value is also reduced, and the molding cycle is also excellent. Furthermore, outgassing properties also tend to be improved.

[0022] In the polyamide resin of this embodiment, it is preferred 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 preferred that they are structural units derived from terephthalic acid.

[0023] The polyamide resin of this 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 dicarboxylic acid include known aliphatic dicarboxylic acids, such as succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, and dodecanedicarboxylic acid. The polyamide resin of the present embodiment may 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.

[0024] Furthermore, in the polyamide resin of this 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 structure results in a polyamide resin with a higher melting point and a higher glass transition temperature. It also reduces 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. A structural unit having one cyclic structure (usually a structural unit formed from one monomer) preferably contains either an aromatic ring or an alicyclic ring.

[0025] Specific examples of the polyamide resin of the present embodiment include the following: It goes without saying that the polyamide resin of the present 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 %, and 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 %, and 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 %, and 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 %, and 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).

[0026] The polyamide resin of this 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, 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 this embodiment may contain trace components such as additives used in the synthesis. The polyamide resin of the present embodiment is preferably composed of dicarboxylic acid-derived structural units and diamine-derived structural units at 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, still more preferably 95% by mass or more, and even more preferably 98% by mass or more.

[0027] <Physical properties of polyamide resin> Next, the physical properties of the polyamide resin of this embodiment will be described. The polyamide resin of the present embodiment may be a crystalline polyamide resin or an amorphous polyamide resin, but is preferably a crystalline polyamide resin. The polyamide resin of this embodiment preferably has a melting point (Tm) according to differential scanning calorimetry of 200°C or higher, more preferably 240°C or higher, even more preferably 285°C or higher, even more preferably 290°C or higher, even more preferably 295°C or higher, and even more preferably 300°C or higher. By setting the melting point at or above the lower limit, deformation and / or surface roughness of molded articles made from the polyamide resin of this embodiment tend to be effectively reduced when lead-reduced and / or lead-free soldering is performed on the molded article. The upper limit of the melting point is preferably 320°C or lower, more preferably 315°C or lower, even more preferably 312°C or lower, and even more preferably 310°C or lower. Setting the melting point at or below the upper limit tends to further reduce the mass loss rate and further improve thermal stability during molding. The melting point is measured according to the method described in the Examples below.

[0028] The polyamide resin of this embodiment preferably has a glass transition temperature (Tg) according to differential scanning calorimetry of 80°C or higher, more preferably 90°C or higher, even more preferably 100°C or higher, even more preferably 120°C or higher, and even more preferably 128°C or higher. By setting the Tg at or above the lower limit, a high elastic modulus can be more effectively maintained even in high-temperature environments. The glass transition temperature is also preferably 160°C or lower, more preferably 155°C or lower, even more preferably 150°C or lower, and even more preferably 145°C or lower. By setting the Tg at or below the upper limit, fluidity during melting increases, and moldability tends to be further improved. The glass transition temperature is measured according to the method described in the Examples below.

[0029] The polyamide resin of this embodiment preferably has a cooling crystallization temperature (Tcc) measured by differential scanning calorimetry of 140°C or higher, more preferably 165°C or higher, even more preferably 205°C or higher, even more preferably 245°C or higher, and even more preferably 253°C or higher. By setting the Tcc at or above the lower limit, the crystallinity of the polyamide resin tends to be improved, and the crystallinity and high-temperature strength of the molded article tend to be improved. The cooling crystallization temperature is also preferably 310°C or lower, more preferably 300°C or lower, even more preferably 290°C or lower, and even more preferably 280°C or lower. By setting the Tcc at or below the upper limit, the mold shrinkage tends to be small. The cooling crystallization temperature is measured according to the method described in the Examples below.

[0030] The upper limit of the temperature difference between the melting point and the cooling crystallization temperature (Tm-Tcc) of the polyamide resin of this embodiment is preferably 80° C. or less, more preferably 70° C. or less, even more preferably 55° C. or less, even more preferably 50° C. or less, and still more preferably 45° C. or less. By setting the temperature difference to the above upper limit or less, the molding cycle of the polyamide resin is shortened and moldability is improved. In the polyamide resin of the present embodiment, the lower limit of the temperature difference between the melting point and the cooling crystallization temperature (Tm-Tcc) is preferably 10° C. or more, more preferably 15° C. or more, even more preferably 20° C. or more, even more preferably 25° C. or more, and still more preferably 28° C. or more. By making the temperature equal to or more than the lower limit, the molding shrinkage rate tends to be small.

[0031] The polyamide resin of this embodiment preferably has a temperature-decreasing crystallization enthalpy change (ΔH(Tcc)) evaluated by differential scanning calorimetry of 5 J / g or more, more preferably 10 J / g or more, even more preferably 20 J / g or more, even more preferably 28 J / g or more, and even more preferably 35 J / g or more. By setting ΔH(Tcc) at or above the lower limit, moldability tends to be further improved. Furthermore, ΔH(Tcc) is preferably 70 J / g or less, more preferably 65 J / g or less, even more preferably 60 J / g or less, even more preferably 55 J / g or less, and even more preferably 50 J / g or less. By setting ΔH(Tcc) at or below the upper limit, mold shrinkage tends to be small.

[0032] The polyamide resin of this embodiment preferably has an enthalpy change (ΔH) upon melting, as evaluated by differential scanning calorimetry, of 0 J / g or more, more preferably greater than 0 J / g, even more preferably 1 J / g or more, even more preferably 5 J / g or more, even more preferably 12 J / g or more, even more preferably 20 J / g or more, and particularly preferably 35 J / g or more. By setting the enthalpy change (ΔH) at or above the lower limit, the crystallinity of the polyamide resin tends to be improved, and the crystallinity and high-temperature strength of the molded article tend to be further improved. Furthermore, the enthalpy change (ΔH) upon melting is preferably 60 J / g or less, more preferably 55 J / g or less, and even more preferably 50 J / g or less. By setting the enthalpy change (ΔH) at or below the upper limit, moldability tends to be improved and mold shrinkage tends to be reduced. The enthalpy change (ΔH) upon melting is measured according to the method described in the Examples below.

[0033] The polyamide resin of this embodiment preferably has a low mass loss rate after heating for 30 minutes at a temperature of melting point + 25°C according to differential scanning calorimetry. Specifically, the mass loss rate is preferably 4.0% or less, more preferably 3.5% or less, even more preferably 3.0% or less, even more preferably 2.5% or less, and even more preferably 2.0% or less. By keeping the mass loss rate below the upper limit, thermal stability during molding tends to be further improved, and moldability tends to be further improved. The lower limit of the mass loss rate is preferably 0%, but a value of 0.01% or more is practical. The mass loss rate is measured according to the method described in the Examples below.

[0034] <Method of manufacturing polyamide resin> The polyamide resin of this embodiment is preferably produced by melt polycondensation (melt polymerization) using a phosphorus atom-containing compound as a catalyst, or by a pressurized salt method, and more preferably by a pressurized salt method. A preferred melt polycondensation method involves adding a raw diamine dropwise to a molten dicarboxylic acid, raising the temperature under pressure, and polymerizing the resulting mixture while removing the condensed water. A preferred pressurized salt method involves raising the temperature of a salt composed of the raw diamine and the resulting dicarboxylic acid in the presence of water under pressure, and polymerizing the resulting mixture in a molten state while removing the added water and the condensed water. Specific examples of the phosphorus atom-containing compound include phosphinic acid compounds such as dimethylphosphinic acid and phenylmethylphosphinic acid; hypophosphorous acid compounds such as hypophosphorous acid, sodium hypophosphite, potassium hypophosphite, lithium hypophosphite, magnesium hypophosphite, calcium hypophosphite, and ethyl hypophosphite; and phosphonic acid compounds such as phosphonic acid, sodium phosphonate, lithium phosphonate, potassium phosphonate, magnesium phosphonate, calcium phosphonate, phenylphosphonic acid, ethylphosphonic acid, sodium phenylphosphonate, potassium phenylphosphonate, lithium phenylphosphonate, diethyl phenylphosphonate, sodium ethylphosphonate, and potassium ethylphosphonate. phosphonous acid compounds such as phosphonous acid, sodium phosphonite, lithium phosphonite, potassium phosphonite, magnesium phosphonite, calcium phosphonite, phenylphosphonous acid, sodium phenylphosphonite, potassium phenylphosphonite, lithium phenylphosphonite, and ethyl phenylphosphonite; and phosphite compounds such as phosphorous acid, sodium hydrogen phosphite, sodium phosphite, lithium phosphite, potassium phosphite, magnesium phosphite, calcium phosphite, triethyl phosphite, triphenyl phosphite, and pyrophosphorous acid, with sodium hypophosphite and calcium hypophosphite being preferred, and calcium hypophosphite being more preferred. Use of calcium hypophosphite tends to further improve the heat resistance of the resulting polyamide resin. These phosphorus atom-containing compounds can be used alone or in combination of two or more. The amount of the phosphorus atom-containing compound added is preferably an amount that results in a phosphorus atom concentration of 0.001 to 0.1% by mass in the polyamide resin, which tends to improve the heat resistance of the polyamide resin and reduce the mass loss rate at temperatures slightly higher than the melting point.

[0035] In this embodiment, a polymerization rate regulator may be added in addition to the phosphorus atom-containing compound. Examples of the polymerization rate regulator include alkali metal hydroxides, alkaline earth metal hydroxides, alkali metal acetates, and alkaline earth metal acetates, with alkali metal acetates being preferred. Examples of alkali metal atoms include sodium, potassium, and lithium, with sodium being preferred, and examples of alkaline earth metal atoms include calcium and magnesium. Specific examples of the polymerization rate regulator include lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide, magnesium hydroxide, calcium hydroxide, strontium hydroxide, barium hydroxide, lithium acetate, sodium acetate, potassium acetate, rubidium acetate, cesium acetate, magnesium acetate, calcium acetate, strontium acetate, and barium acetate. Among these, at least one selected from sodium hydroxide, potassium hydroxide, magnesium hydroxide, calcium hydroxide, sodium acetate, potassium acetate, and calcium acetate is preferred, at least one selected from sodium acetate, potassium acetate, and calcium acetate is more preferred, and sodium acetate is even more preferred. These polymerization rate regulators can be used alone or in combination of two or more. The amount of the polymerization rate regulator added is preferably 0.001 to 0.5% by mass of the total amount of the raw material diamine and dicarboxylic acid.

[0036] <Resin composition> The polyamide resin of the present embodiment can be used as a resin composition containing the polyamide resin of the present embodiment (hereinafter sometimes referred to as the "resin composition of the present embodiment"), and further as a molded article formed from the resin composition of the present embodiment. The resin composition of the present embodiment may consist of only one or more polyamide resins of the present embodiment, or may contain other components. Other components that may be added as needed include polyamide resins other than the polyamide resin of this embodiment, thermoplastic resins other than polyamide resins, reinforcing materials (fillers), antioxidants (particularly heat stabilizers) such as heat stabilizers and weather stabilizers, flame retardants, flame retardant assistants, release agents, anti-dripping agents, delustering agents, UV absorbers, plasticizers, antistatic agents, color inhibitors, anti-gelling agents, etc. Each of these additives may be one type or two or more types.

[0037] <<Other polyamide resins>> The other polyamide resin that may be contained in the resin composition of the present embodiment may be an aliphatic polyamide resin or a semi-aromatic polyamide resin. Examples of aliphatic polyamide resins include polyamide 6, polyamide 66, polyamide 46, polyamide 6 / 66 (a copolymer consisting of a polyamide 6 component and a polyamide 66 component), polyamide 610, polyamide 612, polyamide 410, polyamide 1010, polyamide 11, polyamide 12, and polyamide 9C (a polyamide consisting of a mixed diamine consisting of 1,9-nonanediamine and 2-methyl-1,8-octanediamine and 1,4-cyclohexanedicarboxylic acid). Examples of semi-aromatic polyamide resins include polyamide 4T, polyamide 6T, polyamide 6I, polyamide 6T / 6I, polyamide 9T, polyamide 10T, and polyamide 9N (a polyamide made from a mixed diamine of 1,9-nonanediamine and 2-methyl-1,8-octanediamine and 2,6-naphthalenedicarboxylic acid). An example of a semi-aromatic polyamide resin is a xylylenediamine-based polyamide resin that is composed of diamine-derived structural units and dicarboxylic acid-derived structural units, with 70 mol % or more of the diamine-derived structural units being derived from at least one of meta-xylylenediamine and para-xylylenediamine, and 70 mol % or more of the dicarboxylic acid-derived structural units being derived from an α,ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms. Specific examples include MXD6, a polycondensate of meta-xylylenediamine and adipic acid, MXD6I, a polycondensate of meta-xylylenediamine, adipic acid, and isophthalic acid, MP6, a polycondensate of meta-xylylenediamine, para-xylylenediamine, and adipic acid, MXD10, a polycondensate of meta-xylylenediamine and sebacic acid, MP10, a polycondensate of meta-xylylenediamine, para-xylylenediamine, and sebacic acid, and PXD10, a polycondensate of para-xylylenediamine and sebacic acid. Further examples of semi-aromatic polyamide resins include polyamide resins that are polycondensates of at least one of 1,9-nonanediamine, 2-methyl-1,8-octanediamine, and 1,10-decanediamine with terephthalic acid and / or naphthalenedicarboxylic acid. In particular, polyamide resins that are polycondensates of 1,9-nonanediamine, 2-methyl-1,8-octanediamine, and naphthalenedicarboxylic acid are preferred.

[0038] When the resin composition of this embodiment contains another polyamide resin, the content thereof is preferably 1 part by mass or more, and may be 10 parts by mass or more, relative to 100 parts by mass of the polyamide resin of this embodiment, and is preferably 100 parts by mass or less, more preferably 50 parts by mass or less, and even more preferably 30 parts by mass or less. The resin composition of this embodiment may contain only one type of other polyamide resin, or may contain two or more types. When two or more types are contained, the total amount is preferably within the above range.

[0039] <<Thermoplastic resins other than polyamide resins>> Examples of thermoplastic resins other than polyamide resins include polyester resins such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, etc. These thermoplastic resins other than polyamide resins may each be one type or two or more types.

[0040] <<Antioxidants>> The resin composition of the present embodiment may further contain an antioxidant. By containing an antioxidant, a molded article having excellent heat resistance can be obtained. The antioxidant may include an organic antioxidant, more specifically, a primary antioxidant and a secondary antioxidant. The antioxidant may include an inorganic antioxidant. Furthermore, both an organic antioxidant and an inorganic antioxidant may be included.

[0041] The primary antioxidant acts as a so-called radical scavenger, and plays a role in capturing various radicals generated by autoxidation, for example, to generate hydroperoxides. Examples of the primary antioxidant include phenolic antioxidants (preferably hindered phenolic antioxidants) and amine antioxidants. The secondary antioxidant acts as a so-called peroxide decomposer, for example, by decomposing generated hydroperoxides and converting them into stable alcohol compounds. Examples of the secondary antioxidant include phosphorus-based antioxidants and sulfur-based antioxidants. By using the primary antioxidant and secondary antioxidant in combination, the antioxidant functions act in a chain reaction, enabling more effective antioxidant effects to be achieved. It is particularly preferable to use a phenolic antioxidant (preferably a hindered phenolic antioxidant) in combination with a phosphorus-based antioxidant. When the primary antioxidant and secondary antioxidant are used in combination, the ratio of the mixture is preferably 1:0.1 to 1:10 (mass ratio), and more preferably 1:0.5 to 1:2.

[0042] Specifically, the phenolic antioxidant is preferably a hindered phenolic antioxidant. Here, the hindered phenolic antioxidant is, for example, a compound having a hindered phenol structure in which at least one of the carbon atoms on either side of the carbon atom to which the OH group of the phenyl group is bonded has a bulky substituent, and the bulky substituent is generally a t-butyl group. Hindered phenolic antioxidants are generally classified into hindered and less hindered types, and the hindered type is preferred. The hindered type is a compound in which a bulky substituent is present on each of the carbon atoms on either side of the carbon atom to which the OH group of the phenyl group is bonded. On the other hand, the less hindered type is a hindered phenolic antioxidant in which a bulky substituent is present on only one of the carbon atoms on either side of the carbon atom to which the OH group of the phenyl group is bonded, or a hindered phenolic antioxidant in which no bulky substituent is present on either of the carbon atoms at both ends. In particular, in this embodiment, a hindered phenol-based antioxidant having 2 to 6 hindered phenol structures is preferred, and a hindered phenol-based antioxidant having two hindered phenol structures is more preferred. In this embodiment, a hindered phenol-based antioxidant having an amide bond is preferred, a hindered hindered phenol-based antioxidant having an amide bond is more preferred, a hindered phenol-based antioxidant having 2 to 6 amide bonds and 2 to 6 hindered hindered phenol structures is more preferred, a hindered phenol-based antioxidant having 2 to 6 di-tert-butyl-4 hydroxyphenylalkylcarbonylamide groups (the number of carbon atoms in the alkyl chain portion is preferably 1 to 5, and more preferably 2 to 4), is even more preferred, and N,N'-(hexane-1,6-diyl)bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionamide] is particularly preferred. As commercially available hindered phenol-based antioxidants, antioxidants sold by BASF as the Irganox series and antioxidants sold by ADEKA as the Adeka STAB series (e.g., AO-20, AO-50, AO-50F, AO-60, AO-60G, AO-330) are preferred, and Irganox 1098 is preferred.

[0043] Examples of antioxidants that are preferably used in this embodiment are listed below, but it goes without saying that this embodiment is not limited to these. [ka] [ka]

[0044] Amine antioxidants include N,N'-di-2-naphthyl-p-phenylenediamine, N,N-diphenylethylenediamine, N,N-diphenylacetamidine, N,N-diphenylformamidine, N-phenylpiperidine, dibenzylethylenediamine, triethanolamine, phenothiazine, N,N'-di-sec-butyl-p-phenylenediamine, 4,4'-tetramethyl-diaminodiphenylmethane, P,P'-dioctyl-diphenylamine, N,N'-bis(1,4-dimethyl- Examples of amines include amines such as N-phenyl-N'-isopropyl-p-phenylenediamine, N-phenyl-N'-(1,3-dimethylbutyl)-p-phenylenediamine, reaction products of amines and aldehydes, and reaction products of amines and ketones. In this embodiment, an amine-based antioxidant containing an aromatic ring is particularly preferred, and an amine-based antioxidant containing two or more (preferably 2 to 5) benzene rings is more preferred. The amine-based antioxidants represented by the following formula (A) and formula (B) are preferred. Formula (A) [ka] (In formula (A), R A1 and R A2 are each independently a hydrocarbon group. R A1 and R A2 is preferably an alkyl group or an aryl group, and R A1 and R A2 It is more preferable that at least one of the alkyl group and the aryl group is an aryl group. The alkyl group and the aryl group may have a substituent. Examples of the aryl group include a phenyl group and a naphthyl group. Formula (B) [ka] (In formula (B), R B1 and R B2 are each independently a hydrocarbon group containing an aromatic ring. R B1 and R B2 is preferably a hydrocarbon group containing two or more aromatic rings, more preferably a hydrocarbon group containing two aromatic rings, even more preferably a hydrocarbon group containing two benzene rings, and even more preferably a hydrocarbon group in which two benzene rings are linked by an alkylene group having 1 to 4 carbon atoms. The amine-based antioxidant represented by formula (A) and the amine-based antioxidant represented by formula (B) preferably have a molecular weight of 200-1200, more preferably 300-600. The antioxidant represented by formula (A) has two amines as active sites, which is thought to be the reason why the effects of this embodiment are effectively exhibited. Furthermore, other compounds may be copolymerized within the scope of this embodiment.

[0045] Examples of phosphorus-based antioxidants include phosphites and phosphates, with phosphites being more preferred.Specific examples of the phosphorus-based antioxidant include monosodium phosphate, disodium phosphate, trisodium phosphate, sodium phosphite, calcium phosphite, magnesium phosphite, manganese phosphite, pentaerythritol-type phosphite compounds, trioctyl phosphite, trilauryl phosphite, octyl diphenyl phosphite, trisisodecyl phosphite, phenyl diisodecyl phosphite, phenyl di(tridecyl) phosphite, diphenyl isooctyl phosphite, diphenyl isodecyl phosphite, diphenyl (tridecyl) phosphite, decyl) phosphite, triphenyl phosphite, trioctadecyl phosphite, tridecyl phosphite, tri(nonylphenyl) phosphite, tris(2,4-di-tert-butylphenyl) phosphite, tris(2,4-di-tert-butyl-5-methylphenyl) phosphite, tris(butoxyethyl) phosphite, 4,4'-butylidene-bis(3-methyl-6-tert-butylphenyl-tetratridecyl) diphosphite, tetra(C12-C15 mixed alkyl)-4,4'-isopropylidene diphenyl diphosphite phosphite, 4,4'-isopropylidenebis(2-tert-butylphenyl)di(nonylphenyl)phosphite, tris(biphenyl)phosphite, tetra(tridecyl)-1,1,3-tris(2-methyl-5-tert-butyl-4-hydroxyphenyl)butane diphosphite, tetra(tridecyl)-4,4'-butylidenebis(3-methyl-6-tert-butylphenyl)diphosphite, tetra(C1-C15 mixed alkyl)-4,4'-isopropylidenediphenyl diphosphite, tris(mono- and di-mixed nonylphenyl)phosphite Phosphite, 4,4'-isopropylidenebis(2-tert-butylphenyl)di(nonylphenyl)phosphite, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, tris(3,5-di-tert-butyl-4-hydroxyphenyl)phosphite, hydrogenated 4,4'-isopropylidenediphenyl polyphosphite, bis(octylphenyl)bis(4,4'-butylidenebis(3-methyl-6-tert-butylphenyl))1,6-hexanol diphosphite, hexatridecyl-1,1,3-Tris(2-methyl-4-hydroxy-5-tert-butylphenyl)diphosphite, tris(4,4'-isopropylidenebis(2-tert-butylphenyl))phosphite, tris(1,3-stearoyloxyisopropyl)phosphite, 2,2-methylenebis(4,6-di-tert-butylphenyl)octylphosphite, 2,2-methylenebis(3-methyl-4,6-di-tert-butylphenyl)-2-ethylhexyl tetrakis(2,4-di-tert-butyl-5-methylphenyl)-4,4'-biphenylene diphosphite, tetrakis(2,4-di-tert-butylphenyl)-4,4'-biphenylene diphosphite, 6-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propoxy]-2,4,8,10-tetra-tert-butyldibenzo[d,f][1,3,2]-dioxaphosphepine, and the like.

[0046] In this embodiment, a phosphorus-based antioxidant represented by the following formula (P) is particularly preferred. Formula (P) [ka] (In formula (P), R P1 and R P2 are each independently a hydrocarbon group. R P1 and R P2 is preferably an aryl group, more preferably a phenyl group. The aryl group may have a substituent. Examples of the substituent include a hydrocarbon group, and an alkyl group is preferred. The substituent may further have a substituent such as a hydrocarbon group. The compound represented by formula (P) preferably has a molecular weight of 400-1200, more preferably 500-800.

[0047] Examples of sulfur-based antioxidants include dilauryl thiodipropionate, distearyl thiodipropionate, dimyristyl thiodipropionate, laurylstearyl thiodipropionate, pentaerythritol tetrakis(3-dodecylthiopropionate), and pentaerythritol tetrakis(3-laurylthiopropionate). For example, commercially available products such as DSTP "Yoshitomi," DLTP "Yoshitomi," DLTOIB, and DMTP "Yoshitomi" (all manufactured by API Corporation), Seenox 412S (manufactured by Shipro Chemical Co., Ltd.), Cyanox 1212 (manufactured by Cyanamid), and SUMILIZER TP-D (manufactured by Sumitomo Chemical Co., Ltd.) can be used (all are trade names).

[0048] Examples of inorganic antioxidants include copper compounds and alkali halides. Examples of the copper compound used in this embodiment include copper halides (e.g., copper iodide, copper bromide, copper chloride) and copper acetate. The copper compound is preferably selected from among copper (I) iodide, copper (II) iodide, copper (I) bromide, copper (II) bromide, copper (I) acetate, copper (II) acetate, copper (I) chloride, and copper (II) chloride, and more preferably selected from copper iodide, copper acetate, and copper (I) chloride.

[0049] The alkali halide used in this embodiment refers to a halide of an alkali metal. As the alkali metal, potassium and sodium are preferred, and potassium is more preferred. Furthermore, as the halogen atom, iodine, bromine, and chlorine are preferred, and iodine is more preferred. Specific examples of the alkali halide used in this embodiment include potassium iodide, potassium bromide, potassium chloride, and sodium chloride.

[0050] It is also preferable to use a combination of a copper compound and an alkali halide. When a copper compound and an alkali halide are combined, the mixture is preferably a copper compound:alkali halide mixture with a mass ratio of 1:3 to 1:15, more preferably a mixture with a mass ratio of 1:4 to 1:8. When a copper compound and an alkali halide are combined, the disclosures in paragraphs 0046 to 0048 of JP-A No. 2013-513681 may also be taken into consideration, the contents of which are incorporated herein by reference.

[0051] In addition, as an antioxidant other than those described above, a mixture of a copper complex and a halogen-containing phosphate can also be used, and a mixture of this copper complex and a halogen-containing phosphate with the above-mentioned antioxidant can also be used. The antioxidants described in paragraphs 0025 to 0039 of JP-A No. 2019-532168 can also be used, the contents of which are incorporated herein by reference.

[0052] In addition, polyhydric alcohols can also be used as antioxidants other than those described above, and mixtures of such polyhydric alcohols with the above antioxidants can also be used. Antioxidants described in paragraphs 0039 to 0045 of JP-T No. 2013-538927 and paragraphs 0083 to 0085 of JP-T No. 2014-525506 can also be used, the contents of which are incorporated herein by reference.

[0053] In addition, metal cyanide salts can also be used as antioxidants other than those described above, and mixtures of these metal cyanide salts with the above antioxidants can also be used. Antioxidants described in paragraphs 0018 to 0019 of WO2018 / 101163 can also be used, the contents of which are incorporated herein by reference.

[0054] In addition to the above, examples of the antioxidant include the antioxidants described in paragraphs 0025 to 0030 of Japanese Patent Publication No. 6466632, the antioxidants described in paragraphs 0017 to 0020 of Japanese Patent Application Laid-Open No. 2016-074804, the antioxidants described in paragraphs 0044 to 0048 of Japanese Patent Application Laid-Open No. 2021-038370, the antioxidants described in paragraphs 0043 to 0056 of Japanese Patent Application Laid-Open No. 2012-179911, the antioxidants described in paragraphs 0045 to 0056 of Japanese Patent Application Laid-Open No. 2020-033539, and the antioxidants described in paragraphs 0030 to 0038 of International Publication No. 2010 / 143638. The contents of these antioxidants are incorporated herein by reference.

[0055] When the resin composition of this embodiment contains an antioxidant, the content thereof is preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, even more preferably 0.1 parts by mass or more, even more preferably 0.2 parts by mass or more, and even more preferably 0.4 parts by mass or more, relative to 100 parts by mass of the polyamide resin. By setting the content at or above the lower limit, the retention of the weight-average molecular weight after heat aging and the retention of mechanical strength tend to be improved. Furthermore, the content is preferably 10.0 parts by mass or less, more preferably 5.0 parts by mass or less, even more preferably 3.0 parts by mass or less, even more preferably 2.0 parts by mass or less, and even more preferably 1.5 parts by mass or less, relative to 100 parts by mass of the polyamide resin. Setting the content at or below the upper limit reduces outgassing during molding, thereby reducing mold contamination and tending to improve continuous productivity. The resin composition of the present embodiment may contain only one type of antioxidant, or may contain two or more types. When two or more types are contained, the total amount is preferably in the above range.

[0056] <<Flame retardants>> The resin composition of the present embodiment may contain a flame retardant, which can improve flame retardancy. Examples of flame retardants include phosphorus-based flame retardants, halogen-based flame retardants, and organic metal salt-based flame retardants, with phosphorus-based flame retardants and halogen-based flame retardants being preferred, and phosphorus-based flame retardants being more preferred.

[0057] Examples of phosphorus-based flame retardants include metal ethylphosphinate, metal diethylphosphinate, melamine polyphosphate, condensed phosphate esters, and phosphazene compounds, with condensed phosphate esters and phosphazenes being preferred. Furthermore, to suppress the generation of gas and mold deposits during molding and the bleed-out of the flame retardant, a thermoplastic resin that is highly compatible with the phosphorus-based flame retardant may be blended. Such thermoplastic resins are preferably polyphenylene ether resins, polycarbonate resins, or styrene-based resins.

[0058] The condensed phosphate ester is preferably a compound represented by the following formula (FP1). Formula (FP1) [ka] (In formula (FP1), R f1 , R f2 , R f3 and R f4 each independently represents a hydrogen atom or an organic group. f1 , R f2 , R f3 and R f4 are all hydrogen atoms. X represents a divalent organic group, p is 0 or 1, q is an integer of 1 or more, and r is an integer of 0 or 1 or more.

[0059] In the above formula (FP1), examples of the organic group include an alkyl group, a cycloalkyl group, and an aryl group. The organic group may have a substituent such as an alkyl group, an alkoxy group, an alkylthio group, an aryl group, an aryloxy group, an arylthio group, a halogen atom, or an aryl halide group. The organic group may also be a group formed by combining these substituents, or a group formed by combining these substituents through an oxygen atom, a sulfur atom, a nitrogen atom, or the like. The divalent organic group refers to a divalent group formed by removing one carbon atom from the above organic group. Examples include an alkylene group, a phenylene group, a substituted phenylene group, and a polynuclear phenylene group derived from a bisphenol. The formula weight of each of these groups is preferably 15 to 300, more preferably 15 to 200, and even more preferably 15 to 100.

[0060] Specific examples of the condensed phosphate ester represented by the above formula (FP1) include, for example, trimethyl phosphate, triethyl phosphate, tributyl phosphate, trioctyl phosphate, triphenyl phosphate, tricresyl phosphate, tricresyl phenyl phosphate, octyl diphenyl phosphate, diisopropyl phenyl phosphate, tris(chloroethyl) phosphate, tris(dichloropropyl) phosphate, tris(chloropropyl) phosphate, bis(chloroethyl) phosphate, Examples include (2,3-dibromopropyl)phosphate, bis(2,3-dibromopropyl)-2,3-dichlorophosphate, bis(chloropropyl)monoctylphosphate, bisphenol A tetraphenyl phosphate, bisphenol A tetracresyl diphosphate, bisphenol A tetraxylyl diphosphate, hydroquinone tetraphenyl diphosphate, hydroquinone tetracresyl phosphate, and hydroquinone tetraxylyl diphosphate. Commercially available condensed phosphate esters are readily available, such as those sold by Daihachi Chemical Industry Co., Ltd. under the trade names "CR733S" (resorcinol bis(diphenyl phosphate)), "CR741" (bisphenol A bis(diphenyl phosphate)), and "PX-200" (resorcinol bis(dixylenyl phosphate)), and by Asahi Denka Kogyo Co., Ltd. under the trade names "ADK STAB FP-700" (phenol condensate of 2,2-bis(p-hydroxyphenyl)propane-trichlorophosphine oxide polycondensate (degree of polymerization 1 to 3)).

[0061] The phosphazene compound is an organic compound having a -P=N- bond in the molecule, and is preferably at least one compound selected from the group consisting of a cyclic phosphazene compound represented by formula (FP2), a chain phosphazene compound represented by formula (FP3), and a crosslinked phosphazene compound obtained by crosslinking at least one phosphazene compound selected from the group consisting of formulas (FP2) and (FP3) with a crosslinking group.

[0062] Formula (FP2) [ka] (In formula (FP2), a is an integer of 3 to 25, and R f5 and R f6 may be the same or different and represent an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryloxy group, an amino group, a hydroxy group, an aryl group, or an alkylaryl group.

[0063] Formula (FP3) [ka] (In formula (FP3), b is an integer of 3 to 10,000, and R f7 and R f8 may be the same or different and represent an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryloxy group, an amino group, a hydroxy group, an aryl group, or an alkylaryl group. R f9 is -N=P(OR f7 ) 3 groups, -N=P(OR f8 ) 3 groups, -N=P(O)OR f7 Group, -N=P(O)OR f8 represents at least one selected from the group R f10 is -P(OR f7 ) 4 groups, -P(OR f8 ) 4 groups, -P(O)(OR f7 ) 2 groups, -P(O)(OR f8 ) represents at least one selected from the following two groups.

[0064] In formula (FP2) and formula (FP3), examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a t-butyl group, a pentyl group, a hexyl group, an octyl group, a decyl group, and a dodecyl group. Of these, an alkyl group having 1 to 6 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a t-butyl group, a pentyl group, or a hexyl group, is preferred, and an alkyl group having 1 to 4 carbon atoms, such as a methyl group, an ethyl group, or a propyl group, is particularly preferred.

[0065] Examples of the cycloalkyl group include cycloalkyl groups having 5 to 14 carbon atoms, such as cyclopentyl and cyclohexyl groups, and cycloalkyl groups having 5 to 8 carbon atoms are preferred.

[0066] Examples of the alkenyl group include alkenyl groups having 2 to 8 carbon atoms, such as a vinyl group and an allyl group. Examples of the cycloalkenyl group include cycloalkenyl groups having 5 to 12 carbon atoms, such as a cyclopentenyl group and a cyclohexenyl group.

[0067] Examples of the alkynyl group include alkynyl groups having 2 to 8 carbon atoms, such as ethynyl and propynyl groups, and alkynyl groups having an aryl group as a substituent, such as ethynylbenzene groups.

[0068] Examples of the aryl group include aryl groups having 6 to 20 carbon atoms, such as a phenyl group, a methylphenyl (i.e., tolyl) group, a dimethylphenyl (i.e., xylyl) group, a trimethylphenyl group, and a naphthyl group. Among these, aryl groups having 6 to 10 carbon atoms are preferred, and a phenyl group is particularly preferred.

[0069] Examples of the alkylaryl group include aralkyl groups having 6 to 20 carbon atoms, such as benzyl, phenethyl, and phenylpropyl groups. Of these, aralkyl groups having 7 to 10 carbon atoms are preferred, with benzyl being particularly preferred.

[0070] Among them, R in formula (FP2) f5 and R f6 , R in Equation (FP3) f7 and R f8 However, the aromatic phosphazene is preferably an aryl group or an arylalkyl group, more preferably an aryl group, and further preferably a phenyl group. By using such an aromatic phosphazene, the thermal stability of the resulting resin composition can be effectively improved.

[0071] Examples of the cyclic and / or chain phosphazene compounds represented by formula (FP2) and formula (FP3) include (poly)tolyloxyphosphazenes such as phenoxyphosphazene, o-tolyloxyphosphazene, m-tolyloxyphosphazene, and p-tolyloxyphosphazene, (poly)xylyloxyphosphazenes such as o,m-xylyloxyphosphazene, o,p-xylyloxyphosphazene, and m,p-xylyloxyphosphazene, o,m,p-trimethylphenyloxyphosphazene, and phenoxy-o-tolyloxyphosphazene, Examples include (poly)phenoxytolyloxyphosphazenes such as phosphazene, phenoxy m-tolyloxyphosphazene, and phenoxy p-tolyloxyphosphazene, (poly)phenoxytolyloxyxylyloxyphosphazenes such as phenoxy o,m-xylyloxyphosphazene, phenoxy o,p-xylyloxyphosphazene, and phenoxy m,p-xylyloxyphosphazene, and phenoxy o,m,p-trimethylphenyloxyphosphazene, and preferably cyclic and / or chain phenoxyphosphazenes.

[0072] The cyclic phosphazene compound represented by formula (FP2) includes R f5 and R f6 is a phenyl group. Examples of such cyclic phenoxyphosphazene compounds include compounds such as hexaphenoxycyclotriphosphazene, octaphenoxycyclotetraphosphazene, and decafenoxycyclopentaphosphazene, which are obtained by isolating cyclic chlorophosphazenes such as hexachlorocyclotriphosphazene, octachlorocyclotetraphosphazene, and decachlorocyclopentaphosphazene from a mixture of cyclic and linear chlorophosphazenes obtained by reacting ammonium chloride and phosphorus pentachloride at a temperature of 120 to 130°C, and then substituting the cyclic chlorophosphazenes with phenoxy groups. Furthermore, the cyclic phenoxyphosphazene compound is preferably a compound represented by formula (FP2) in which a is an integer of 3 to 8, and may be a mixture of compounds with different a's.

[0073] The average of the above a is preferably 3 to 5, and more preferably 3 to 4. Among these, a mixture of compounds in which those in which a=3 are 50% by mass or more, those in which a=4 are 10 to 40% by mass, and those in which a=5 or more are 30% by mass or less in total is preferred.

[0074] The chain phosphazene compound represented by formula (FP3) includes R f7 and R f8 is a phenyl group. Examples of such chain phenoxyphosphazene compounds include compounds obtained by ring-opening polymerization of hexachlorocyclotriphosphazene obtained by the above method at a temperature of 220 to 250°C, and substituting the resulting linear dichlorophosphazene having a degree of polymerization of 3 to 10,000 with a phenoxy group. In the linear phenoxyphosphazene compound, b in formula (FP3) is preferably 3 to 1,000, more preferably 3 to 100, and even more preferably 3 to 25.

[0075] Examples of the crosslinked phosphazene compound include compounds having a crosslinked structure of a 4,4'-diphenylene group, such as a compound having a crosslinked structure of 4,4'-sulfonyldiphenylene (i.e., a bisphenol S residue), a compound having a crosslinked structure of a 2,2-(4,4'-diphenylene)isopropylidene group, a compound having a crosslinked structure of a 4,4'-oxydiphenylene group, and a compound having a crosslinked structure of a 4,4'-thiodiphenylene group.

[0076] In addition, the crosslinked phosphazene compound is a compound represented by the formula (FP3) f7 , R f8 a bridged phenoxyphosphazene compound obtained by crosslinking a cyclic phenoxyphosphazene compound in which R is a phenyl group with the above-mentioned crosslinking group, or f7 , R f8is a phenyl group, is crosslinked by the above crosslinking group, is preferred from the viewpoint of flame retardancy, and a bridged phenoxyphosphazene compound is more preferred in which a cyclic phenoxyphosphazene compound is crosslinked by the above crosslinking group. The content of phenylene groups in the crosslinked phenoxyphosphazene compound is usually 50 to 99.9%, preferably 70 to 90%, based on the total number of phenyl groups and phenylene groups in the cyclic phosphazene compound represented by formula (FP2) and / or the chain phenoxyphosphazene compound represented by formula (FP3). It is particularly preferable that the crosslinked phenoxyphosphazene compound is a compound having no free hydroxyl groups in its molecule.

[0077] In this embodiment, the phosphazene compound is preferably at least one selected from the group consisting of a cyclic phenoxyphosphazene compound represented by formula (FP2) and a crosslinked phenoxyphosphazene compound obtained by crosslinking the cyclic phenoxyphosphazene compound represented by formula (FP2) with a crosslinking group, from the viewpoint of flame retardancy and mechanical properties of the resin composition. An example of a commercially available phosphazene compound is FP-110 manufactured by Fushimi Pharmaceutical Co., Ltd.

[0078] The halogen-based flame retardant is preferably a bromine-based flame retardant or a chlorine-based flame retardant, and more preferably a bromine-based flame retardant. Examples of brominated flame retardants include hexabromocyclododecane, decabromodiphenyl oxide, octabromodiphenyl oxide, tetrabromobisphenol A, bis(tribromophenoxy)ethane, bis(pentabromophenoxy)ethane, tetrabromobisphenol A epoxy resin, tetrabromobisphenol A carbonate, ethylene(bistetrabromophthal)imide, ethylenebispentabromodiphenyl, tris(tribromophenoxy)triazine, bis(dibromopropyl)tetrabromobisphenol A, bis(dibromopropyl)tetrabromobisphenol S, brominated polyphenylene ether (including poly(di)bromophenylene ether, etc.), and brominated polystyrene (including polydibromostyrene, polytribromostyrene, crosslinked brominated polystyrene, brominated polycarbonate, etc.).

[0079] As the organic metal salt flame retardant, organic alkali metal salt compounds and organic alkaline earth metal salt compounds are preferred (hereinafter, alkali metals and alkaline earth metals are referred to as "alkali (earth) metals"). In addition, as the organic metal salt flame retardant, metal sulfonates, metal carboxylates, metal borates, metal phosphates, etc. can be mentioned, but metal sulfonates are preferred from the viewpoint of thermal stability when added to aromatic polycarbonate resins, and metal perfluoroalkanesulfonates are particularly preferred.

[0080] Examples of metal sulfonates include lithium (Li) sulfonate, sodium (Na) sulfonate, potassium (K) sulfonate, rubidium (Rb) sulfonate, cesium (Cs) sulfonate, magnesium (Mg) sulfonate, calcium (Ca) sulfonate, strontium (Sr) sulfonate, and barium (Ba) sulfonate. Of these, sodium (Na) sulfonate and potassium (K) sulfonate are particularly preferred.

[0081] Examples of such sulfonic acid metal salts include aromatic sulfonic acid alkali (earth) metal salt compounds such as dipotassium diphenylsulfone-3,3'-disulfonate, potassium diphenylsulfone-3-sulfonate, sodium benzenesulfonate, sodium (poly)styrenesulfonate, sodium paratoluenesulfonate, sodium (branched)dodecylbenzenesulfonate, sodium trichlorobenzenesulfonate, potassium benzenesulfonate, potassium styrenesulfonate, potassium (poly)styrenesulfonate, potassium paratoluenesulfonate, potassium (branched)dodecylbenzenesulfonate, potassium trichlorobenzenesulfonate, cesium benzenesulfonate, cesium (poly)styrenesulfonate, cesium paratoluenesulfonate, cesium (branched)dodecylbenzenesulfonate, and cesium trichlorobenzenesulfonate; and perfluoroalkanesulfonic acid metal salts (the number of carbon atoms of the alkane is preferably 2 to 6) such as perfluoroalkanesulfonic acid alkali metal salts such as potassium perfluorobutanesulfonate. Among these, dipotassium diphenylsulfone-3,3'-disulfonate, potassium diphenylsulfone-3-sulfonate, sodium paratoluenesulfonate, potassium paratoluenesulfonate, and potassium perfluorobutanesulfonate are particularly preferred because they have an excellent balance of transparency and flame retardancy, and metal salts of perfluoroalkanesulfonates such as potassium perfluorobutanesulfonate are particularly preferred.

[0082] When the resin composition of this embodiment contains a flame retardant, the content thereof is preferably 0.01 parts by mass or more, more preferably 1 part by mass or more, even more preferably 5 parts by mass or more, particularly preferably 6 parts by mass or more, and even more preferably 7 parts by mass or more, relative to 100 parts by mass of polyamide resin. The content of the flame retardant is preferably 50 parts by mass or less, more preferably 40 parts by mass or less, particularly preferably 35 parts by mass or less, and even more preferably 30 parts by mass or less, relative to 100 parts by mass of polyamide resin. The resin composition of the present embodiment may contain only one type of flame retardant, or may contain two or more types. When two or more types are contained, the total amount is preferably in the above range.

[0083] <<Flame retardant synergist>> The resin composition of the present embodiment may also contain a flame retardant aid. Examples of the flame retardant aid include antimony compounds, zinc stannate, copper oxide, magnesium oxide, zinc oxide, molybdenum oxide, zirconium oxide, tin oxide, iron oxide, titanium oxide, aluminum oxide, zinc borate, etc., and antimony compounds and zinc stannate are preferred. In particular, zinc stannate is preferred when a phosphorus-based flame retardant is used, and antimony compounds are preferred when a halogen-based flame retardant is used.

[0084] As the zinc stannate, at least one of zinc tin trioxide (ZnSnO3) and zinc tin hexahydroxide (ZnSn(OH)6) is preferred. Antimony compounds are compounds containing antimony that contribute to flame retardancy. Specific examples include antimony oxides such as antimony trioxide (Sb2O3), antimony tetroxide, and antimony pentoxide (Sb2O5), sodium antimonate, and antimony phosphate. Among these, antimony oxide is preferred because of its excellent resistance to moist heat. Antimony trioxide is more preferred.

[0085] The content of the flame retardant aid is preferably such that the flame retardant:flame retardant aid ratio is 1:0.05 to 2.0 (mass ratio), and more preferably 1:0.2 to 1.0. The resin composition of the present embodiment may contain only one type of flame retardant auxiliary, or may contain two or more types. When two or more types are contained, the total amount is preferably in the above range.

[0086] <<Reinforcing material (filler)>> The resin composition of the present embodiment may contain a reinforcing material, and the resin composition preferably contains the reinforcing material in an amount of 5.0 to 60.0% by mass. The reinforcing material that can be used in this embodiment is not particularly limited in terms of type, and may be any of fibers, fillers, flakes, beads, etc., with fibers being preferred.

[0087] When the reinforcing material is a fiber, it may be a short fiber or a long fiber. When the reinforcing material is short fibers, fillers, 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, examples of the reinforcing material include so-called long fiber for unidirectional (UD) materials, sheet-like long fiber such as woven fabric and knitted fabric, etc. When using these long fibers, the components other than the reinforcing material of the resin composition of the present embodiment can be impregnated into the sheet-like long fiber reinforcing material to form a sheet-like resin composition (for example, a prepreg).

[0088] 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 and bamboo), aramid, polyoxymethylene, aromatic polyamide, polyparaphenylene benzobisoxazole, and ultra-high molecular weight polyethylene, with glass being preferred.

[0089] The resin composition of the present embodiment preferably contains glass fibers as a reinforcing material. The glass fiber is 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 fiber refers to a fibrous material whose cross section, cut perpendicular to the longitudinal direction, is circular or polygonal. The number-average fiber diameter of the single fiber of the glass fiber is usually 1 to 25 μm, preferably 5 to 17 μm. By making the number-average fiber diameter 1 μm or more, the molding processability of the resin composition tends to be further improved. By making the number-average fiber diameter 25 μm or less, the appearance of the obtained molded article tends to be improved, and the reinforcing effect also tends to be improved. The glass fiber may be a single fiber or a plurality of single fibers twisted together. 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), but chopped strand cut to a length of 1 to 10 mm is preferred. Glass fibers of different forms can also be used in combination. Glass fibers having an irregular cross-sectional shape are also preferred. The irregular cross-sectional shape has an oblateness, which is the ratio of the major axis to the minor axis of the cross section perpendicular to the longitudinal direction of the fiber, of, for example, 1.5 to 10, preferably 2.5 to 10, more preferably 2.5 to 8, and even more preferably 2.5 to 5.

[0090] 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.

[0091] The reinforcing material used in this embodiment may be a conductive reinforcing material, specifically, a metal, a metal oxide, a conductive carbon compound, or a conductive polymer, and preferably a conductive carbon compound. Examples of metals include copper, nickel, silver, and stainless steel, with metal fillers, stainless steel fibers, and magnetic fillers being preferred. Examples of metal oxides include alumina and zinc oxide, with alumina fibers and zinc oxide nanotubes being preferred. Examples of conductive carbon compounds include carbon black, ketjen carbon, graphene, graphite, fullerene, carbon nanocoils, carbon nanotubes, and carbon fibers, with carbon nanotubes being more preferred. Also preferred are fibers coated with metals, metal oxides, or conductive carbon compounds, such as carbon-coated potassium titanate whiskers and metal-coated fibers. Other reinforcing materials may be found in paragraphs 0033 to 0041 of Japanese Patent Application Laid-Open No. 2021-031633, the contents of which are incorporated herein by reference.

[0092] 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 article 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 article tends to be improved, and the flowability of the resin composition tends to be further improved. The resin composition of the present 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 in the above range.

[0093] <<Nucleating agent>> The resin composition of the present embodiment may contain a nucleating agent, which can increase the crystallization rate.

[0094] The nucleating agent is not particularly limited as long as it remains unmelted during melt processing and can serve as a nucleus for crystals during the cooling process. Either an organic or inorganic nucleating agent may be used, with an inorganic nucleating agent being preferred. Examples of inorganic nucleating agents include graphite, molybdenum disulfide, barium sulfate, talc, calcium carbonate, sodium phosphate, mica, and kaolin, and at least one selected from talc and calcium carbonate is more preferred, with talc being even more preferred. The organic nucleating agent is not particularly limited, and any known nucleating agent can be used. For example, the nucleating agent is preferably at least one selected from dibenzylidene sorbitol-based nucleating agents, nonitol-based nucleating agents, phosphate ester salt-based nucleating agents, rosin-based nucleating agents, and metal benzoate salt-based nucleating agents. The lower limit of the number average particle size of the nucleating agent is preferably 0.1 μm or more. The upper limit of the number average particle size of the nucleating agent is preferably 40 μm or less, more preferably 30 μm or less, even more preferably 28 μm or less, even more preferably 15 μm or less, and even more preferably 10 μm or less. By setting the number average particle size to 40 μm or less, the number of nucleating agents that become nuclei increases compared to the amount of nucleating agent blended, which tends to make the crystal structure more stable.

[0095] The content of the nucleating agent in the resin composition of this embodiment is more than 0.01 parts by mass, preferably 0.05 parts by mass or more, more preferably 0.1 parts by mass or more, even more preferably 0.3 parts by mass or more, and even more preferably 0.7 parts by mass or more, per 100 parts by mass of polyamide resin. By setting the content at or above the lower limit, the crystalline state of the resin composition can be more sufficiently stabilized. Furthermore, the content of the nucleating agent in the resin composition of this embodiment is 10 parts by mass or less, preferably 5 parts by mass or less, more preferably 3 parts by mass or less, and may be 2 parts by mass or less, per 100 parts by mass of polyamide resin. When the resin composition of the present embodiment contains a nucleating agent, it may contain only one type of nucleating agent or may contain two or more types. When two or more types are contained, the total amount is preferably in the above range.

[0096] <<Release Agent>> The resin composition of the present embodiment may contain a release agent. Examples of the release agent include aliphatic carboxylic acids, salts of aliphatic carboxylic acids, esters of aliphatic carboxylic acids and alcohols, aliphatic hydrocarbon compounds having a number average molecular weight of 200 to 15,000, polysiloxane-based silicone oils, ketone waxes, and light amides. Of these, aliphatic carboxylic acids, salts of aliphatic carboxylic acids, and esters of aliphatic carboxylic acids and alcohols are preferred, and salts of aliphatic carboxylic acids are more preferred. For details about the release agent, please refer to paragraphs 0055 to 0061 of JP 2018-095706 A, the contents of which are incorporated herein by reference. When the resin composition of the present embodiment contains a release agent, the content thereof in the resin composition is preferably 0.05 to 3 mass %, more preferably 0.1 to 0.8 mass %, and even more preferably 0.2 to 0.6 mass %. The resin composition of the present embodiment may contain only one type of release agent, or may contain two or more types. When two or more types are contained, the total amount is preferably in the above range.

[0097] <Method of manufacturing resin composition> The method for producing the resin composition of this embodiment is not particularly limited, and a wide variety of known methods for producing thermoplastic resin compositions can be used. Specifically, the resin composition can be produced by pre-mixing the components using various mixers such as a tumbler or a Henschel mixer, and then melt-kneading the mixture using a Banbury mixer, a roll, a Brabender mixer, a single-screw extruder, a twin-screw extruder, a kneader, or the like.

[0098] The resin composition of the present embodiment can also be produced, for example, without mixing the components in advance, or by mixing only some of the components in advance and supplying the mixture to an extruder using a feeder and melt-kneading it.Furthermore, the resin composition of the present embodiment can also be produced, for example, by mixing some of the components in advance, supplying them to an extruder and melt-kneading them to obtain a resin composition, which is used as a masterbatch, and then mixing this masterbatch again with the remaining components and melt-kneading them.

[0099] <Molded products> A molded article is formed from the polyamide resin of this embodiment or the resin composition of this embodiment. The method for molding the molded article is not particularly limited, and any conventionally known molding method 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, and the like. Examples of molded articles formed from the composition of the present embodiment include injection molded articles, thin-walled molded articles, hollow molded articles, films (including plate-shaped and sheet-shaped articles), cylindrical shapes (hoses, tubes, etc.), annular, circular, elliptical, gear-shaped, polygonal, irregularly shaped articles, hollow articles, frame-shaped, box-shaped, and panel-shaped extrusion molded articles, fibers, and the like.

[0100] The polyamide resin or polyamide resin composition of the present embodiment is further preferably used as the following material. Examples include a prepreg in which the polyamide resin or polyamide resin composition of this embodiment is impregnated into the above-mentioned reinforcing material (particularly reinforcing fibers, preferably carbon fibers or glass fibers); a mixed yarn, braided cord, or twisted cord containing, as fiber components, continuous thermoplastic resin fibers containing the polyamide resin or polyamide resin composition of this embodiment and continuous reinforcing fibers; a woven or knitted fabric using continuous thermoplastic resin fibers containing the polyamide resin or polyamide resin composition of this embodiment and continuous reinforcing fibers; and a nonwoven fabric composed of thermoplastic resin fibers containing the polyamide resin or polyamide resin composition of this embodiment and reinforcing fibers.

[0101] 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 components, 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 bay parts, cooling system parts, sliding parts, automotive supplies such as electrical components, electronic components, surface-mounted connectors, sockets, camera modules, power supply parts, switches, sensors, capacitor base plates, hard disk components, relays, resistors, fuse holders, coil bobbins, IC housings, and fuel system parts such as 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 fuel 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. [Example]

[0102] The present invention will be described more specifically with reference to the following examples. The materials, amounts used, ratios, processing details, processing procedures, etc. shown in the following examples can be appropriately changed 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. When the measuring instruments and the like used in the examples are difficult to obtain due to obsolescence or the like, measurements can be made using other instruments having equivalent performance.

[0103] <Raw materials> p-BDPA: p-benzenedipropylamine, 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 became 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 in the reactor was released. The contents were filtered and purified by distillation to obtain p-benzenedipropylamine. As a result of analysis using gas chromatography, the purity was 99.3%.

[0104] MXDA: m-xylylenediamine, manufacturer: Tokyo Chemical Industry PXDA: p-xylylenediamine, manufacturer: Tokyo Chemical Industry Hexamethylenediamine: 1,6-hexamethylenediamine, manufacturer: Tokyo Chemical Industry Nonanediamine: 1,9-nonanediamine, manufacturer: Tokyo Chemical Industry Decanediamine: 1,10-decanediamine, manufacturer: Tokyo Chemical Industry

[0105] Isophthalic acid: manufacturer: Tokyo Chemical Industry Terephthalic acid: manufacturer: Tokyo Chemical Industry p-PDAA: p-phenylenediacetic acid, manufacturer: Tokyo Chemical Industry m-PDAA: m-phenylenediacetic acid, manufacturer: Tokyo Chemical Industry Sebacic acid: manufacturer: Tokyo Chemical Industry <​ Calcium hypophosphite: Manufacturer: Fujifilm Wako Pure Chemical Industries Sodium acetate: Manufacturer: Fujifilm Wako Pure Chemical Industries

[0106] Example 1 <<Synthesis of Polyamide Resin>> 0.0034 mol (0.6538 g) of p-BDPA, 0.00340 mol (0.5648 g) of isophthalic acid, and 7.0 g of pure water were placed in a flat-bottom test tube. The test tube was then placed in a 20 mL reactor equipped with a thermometer, pressure gauge, and pressure control valve. The atmosphere inside the reactor was then thoroughly purged with nitrogen, and the reactor was returned to atmospheric pressure. The pressure control valve was then closed. The reactor was heated using an aluminum block heater, and the reactor's internal pressure was maintained at 1.9 MPa and 210°C for 20 minutes, followed by 2.8 MPa and 230°C for 40 minutes. The pressure control valve was then slightly opened while the temperature was raised to 260°C, and the pressure was reduced to atmospheric pressure over 30 minutes while water was removed through the pressure control valve. The reactor was then heated to the melting point +10°C while removing water as needed through the pressure control valve, and held there for 10 minutes. After the reactor was cooled to room temperature, the test tube was taken out to obtain a polyamide resin.

[0107] <<Measurement of melting point (Tm), glass transition temperature (Tg), crystallization temperature (Tcc), crystallization enthalpy change upon cooling (ΔH(Tcc)), and enthalpy change upon melting (ΔH)>> The melting point (Tm), glass transition temperature (Tg), crystallization temperature (Tcc), crystallization enthalpy change (ΔH(Tcc)), and enthalpy change of fusion (ΔH) of the synthesized polyamide resin were measured by differential scanning calorimetry (DSC) in accordance with JIS K7121 and K7122. Specifically, a differential scanning calorimeter was used. The synthesized polyamide resin was crushed and placed in the measurement pan of the differential scanning calorimeter. The temperature was raised to a temperature 20°C above the assumed melting point at a rate of 10°C / min under a nitrogen atmosphere. Immediately after the temperature rise was completed, the measurement pan was removed and pressed against dry ice to rapidly cool. Measurements were then performed on the melting point, glass transition temperature (Tg), and temperature-decreasing crystallization temperature (Tcc). The measurement conditions were as follows: the temperature was raised to approximately 20°C above the assumed melting point at a rate of 10°C / min, held for 5 minutes, and then cooled to 100°C at a rate of -5°C / min. The differential scanning calorimeter used was a "DSC-60" manufactured by Shimadzu Corporation. The units of melting point (Tm) are °C, glass transition temperature (Tg) are °C, cooling crystallization temperature (Tcc) are °C, cooling crystallization enthalpy change (ΔH(Tcc)) are J / g, and enthalpy change at melting (ΔH) are J / g.

[0108] <<Mass reduction rate>> The mass loss rate of the obtained polyamide resin (in a powder state) was measured by thermogravimetric analysis. The obtained polyamide resin was placed in a measuring pan of a thermogravimetric analyzer and heated to the melting point +25°C at a heating rate of 10°C / min under a nitrogen atmosphere, and then heated for 30 minutes. The mass loss rate was measured using the following formula. Mass reduction rate = {[(mass of polyamide resin when heated to melting point - 50°C) - (mass of polyamide resin when heated at melting point + 25°C for 30 minutes)] / (mass of polyamide resin when heated to melting point - 50°C)} x 100 The mass loss rate is expressed in %. The thermogravimetric analyzer used was Shimadzu Corporation's "DTG-60."

[0109] <<Outgassing>> Among the components contained in the obtained polyamide resin, those with low molecular weight, especially cyclic compounds (cyclic monomers) formed by one molecule each of diamine and dicarboxylic acid, tend to volatilize easily during molding and become outgassed. Therefore, to evaluate the outgassing properties of polyamide resin, the amount of cyclic monomer was measured using gel permeation chromatography (GPC). The GPC analyzer used was "HLC-8320GPC" manufactured by Tosoh Corporation. The column used was TSKgel SuperHM-H (manufactured by Tosoh Corporation), the solvent was hexafluoroisopropanol (sodium trifluoroacetate 2 mmol / L solution), and the standard substance was PMMA. The obtained polyamide resin was subjected to GPC measurement at a temperature of 40° C. and a sample concentration of 0.3 g / L, and the areas of the peaks of the cyclic monomer and higher molecular weight components were measured from the GPC chart of the obtained polyamide resin. Outgassing property = {(area of ​​cyclic monomer) / (area of ​​cyclic monomer + area of ​​components with higher molecular weight than cyclic monomer)} x 100 The outgassing property is expressed in units of (%). The lower the outgassing property value, the less likely the outgas is to be generated and the less likely the molding machine or mold to be contaminated during molding, meaning the material has excellent outgassing properties.

[0110] <Examples 2 to 5 and Reference Examples 1 to 7> The same procedures were carried out as in Example 1, except that the types of diamine and dicarboxylic acid were changed as shown in Table 1 or Table 2.

[0111] [Table 1]

[0112] [Table 2]

[0113] As is clear from the above results, the polyamide resin of the present invention had a high glass transition temperature. Furthermore, it also had a high melting point. In other words, the polyamide resin of the present invention had excellent heat resistance. Furthermore, because the Tm-Tcc temperature was low, the molding cycle was short, demonstrating excellent moldability. In addition, the mass loss rate after heating at a temperature of the melting point + 25°C for 30 minutes was also low. Furthermore, outgassing was low. In particular, the use of a p-aromatic dicarboxylic acid as the dicarboxylic acid component further enhanced these properties. Furthermore, the use of an aromatic dicarboxylic acid in which the aromatic ring and the carboxyl group are directly bonded as the dicarboxylic acid component further enhanced these properties.

Claims

1. Contains a diamine-derived structural unit and a dicarboxylic acid-derived structural unit, 50 mol % or more of the diamine-derived constitutional units are derived from a compound represented by formula (1), and the compound represented by formula (1) contains p-benzenedipropanamine, A polyamide resin in which more than 50 mol% of the dicarboxylic acid-derived constitutional units are derived from an aromatic dicarboxylic acid, The polyamide resin is composed of 90 mass % or more of structural units derived from dicarboxylic acid and structural units derived from diamine. Formula (1) 【Chemistry 1】 (In formula (1), R １ ~R ８ each independently represents a hydrogen atom or an aliphatic group having 1 to 5 carbon atoms.

2. 2. The polyamide resin according to claim 1, wherein the enthalpy change (ΔH) upon melting of the polyamide resin as measured by differential scanning calorimetry is 5 to 60 J / g.

3. The polyamide resin according to claim 1 or 2, wherein the aromatic dicarboxylic acid comprises a compound represented by formula (FC1): Formula (FC1) HOOC-Aromatic ring structure-COOH

4. The polyamide resin according to claim 1 or 2, wherein the aromatic dicarboxylic acid comprises a p-aromatic dicarboxylic acid.

5. 3. The polyamide resin according to claim 1, wherein the aromatic dicarboxylic acid comprises at least one selected from the group consisting of isophthalic acid, terephthalic acid, and phenylene diacetic acid.

6. The polyamide resin according to claim 1 or 2, wherein the aromatic dicarboxylic acid comprises terephthalic acid.

7. 70 mol % or more of the diamine-derived constitutional units are derived from p-benzenedipropanamine, The polyamide resin according to claim 1 or 2, wherein more than 70 mol% of the constitutional units derived from the dicarboxylic acid are derived from terephthalic acid.

8. The polyamide resin according to any one of claims 1 to 7, wherein the polyamide resin has a glass transition temperature of 80 to 160°C according to differential scanning calorimetry.

9. The polyamide resin according to any one of claims 1 to 8, wherein the mass loss rate after heating for 30 minutes at a temperature of the melting point of the polyamide resin + 25°C according to differential scanning calorimetry is 4.0% or less.

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