Polyamide resin, resin composition, molded article, method for producing polyamide resin, and method for producing molded article

Abstract

Provided are a polyamide resin, a resin composition, a molded article, a method for producing a polyamide resin, and a method for producing a molded article. A polyamide resin which is a copolymer of a diamine, a dicarboxylic acid, and trimesic acid, wherein 50 mol% or more of the diamine is xylylenediamine, and trimesic acid is 0.01 to 5 mol% based on 100 mol% in total of the diamine, the dicarboxylic acid, and trimesic acid.

Description

Technical Field

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

Background Art

[0002] Polyamide resins are widely used as various industrial materials from the viewpoints of their excellent processability, durability, heat resistance, gas barrier property, chemical resistance, and the like. As such polyamide resins, aliphatic polyamide resins typified by polyamide 6 and polyamide 66 have been used since long ago. Furthermore, aromatic polyamide resins using aromatic dicarboxylic acids and / or aromatic diamines as raw materials of polyamide resins have also come to be used. For example, Patent Document 1 discloses a polyamide resin (A) composed of a diamine structural unit containing 50 mol% or more of a structural unit derived from xylylenediamine and a dicarboxylic acid structural unit, and a polyamide resin composition containing trimesic acid, wherein the content of trimesic acid with respect to 100 parts by mass of the polyamide resin (A) is 0.001 to 2 parts by mass.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The resin composition described in Patent Document 1 can provide a molded article having excellent toughness while maintaining the tensile elastic modulus inherent to the polyamide resin synthesized from metaxylylenediamine and sebacic acid. However, such resin compositions have a low melt viscosity, and different polyamide resins or resin compositions that can be suitable for performing extrusion molding or the like are required. An object of the present invention is to solve such problems, and it is an object to provide a polyamide resin having a high melt viscosity, as well as a resin composition, a molded body, a method for producing a polyamide resin, and a method for producing a molded body.

Means for Solving the Problems

[0005] As a result of investigations by the present inventors based on the above problems, it has been found that the above problems can be solved by using a copolymer of a diamine such as xylylenediamine, a dicarboxylic acid, and trimesic acid. Specifically, the above problems have been solved by the following means. <1>A copolymer of a diamine, a dicarboxylic acid, and trimesic acid, wherein 50 mol% or more of the diamine is xylylenediamine, A polyamide resin in which trimesic acid is 0.01 to 5 mol% with respect to a total of 100 mol% of the diamine, the dicarboxylic acid, and trimesic acid. <2>The polyamide resin according to <1>, wherein 50 mol% or more of the dicarboxylic acid is an α,ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms and / or an aromatic dicarboxylic acid. <3>The polyamide resin according to <1>, wherein 5 to 100 mol% of the dicarboxylic acid is an α,ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms and 95 to 0 mol% is isophthalic acid. <4>The polyamide resin according to <1>, wherein 60 to 40 mol% of the dicarboxylic acid is an α,ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms and 40 to 60 mol% is isophthalic acid. <5>The polyamide resin according to <1>, wherein 97 to 80 mol% of the dicarboxylic acid is an α,ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms and 3 to 20 mol% is isophthalic acid. <6>5 to 100 mol% of the dicarboxylic acid is any one or more of adipic acid, sebacic acid, and dodecanedioic acid, and the polyamide resin according to any one of <1> to <5>. <7>The polyamide resin has a melt viscosity of 510 Pa·s or more measured according to a melt temperature of 250°C and a shear rate of 121.6 s -1 The polyamide resin according to any one of <1> to <6>. <8>A resin composition containing the polyamide resin according to any one of <1> to <7>. <9>A molded article formed from the resin composition containing the polyamide resin according to any one of <1> to <7>. <10>The molded article according to <9>, which is an extruded molded article. <11>The molded article according to <9> or <10>, which is a film, fiber, or foam. <12>Comprising copolymerizing a diamine, a dicarboxylic acid, and trimesic acid, 50 mol% or more of the diamine is xylylenediamine, A method for producing a polyamide resin, wherein trimesic acid is 0.01 to 5 mol% based on a total of 100 mol% of the diamine, the dicarboxylic acid, and trimesic acid. <13>The method for producing a polyamide resin, wherein the polyamide resin is the polyamide resin according to any one of <1> to <7>. <14>A method for producing a molded article, comprising extrusion molding the resin composition according to <8>.

Advantages of the Invention

[0006] According to the present invention, it has become possible to provide a polyamide resin having a high melt viscosity, as well as a resin composition, a molded article, a method for producing a polyamide resin, and a method for producing a molded article.

Embodiments for Carrying Out the Invention

[0007] Hereinafter, embodiments for carrying out the present invention (hereinafter simply referred to as "the present embodiment") will be described in detail. Note that the following present embodiment is an exemplification for explaining the present invention, and the present invention is not limited only to the present embodiment. In this specification, "~" is used to mean including the numerical values described before and after it as the lower limit value and the upper limit value. In this specification, various physical property values and characteristic values are those at 23°C unless otherwise specified. When the measurement methods and the like described according to the standards shown in this specification differ depending on the year, they are based on the standards as of January 1, 2023 unless otherwise specified.

[0008] The polyamide resin of the present embodiment is a copolymer of diamine, dicarboxylic acid, and trimesic acid, wherein 50 mol% or more of the diamine is xylylenediamine, and with respect to a total of 100 mol% of the diamine, dicarboxylic acid, and trimesic acid, trimesic acid is 0.01 to 5 mol%. By adopting such a configuration, it becomes possible to provide a polyamide resin having a high melt viscosity. Regarding the above Patent Document 1, when the present inventor conducted studies, in Patent Document 1, trimesic acid and a predetermined polyamide resin are melt-kneaded. However, in this method, as shown also in the examples of Patent Document 1, trimesic acid does not react with the polyamide resin. In such a resin composition containing polyamide resin and trimesic acid, trimesic acid plays a role like a plasticizer, and it is excellent when injection molding, but it is not always suitable for extrusion molding that requires a high melt viscosity and melt tension. In this embodiment, it is presumed that the melt tension was increased by copolymerizing diamine, dicarboxylic acid, and trimesic acid and incorporating trimesic acid into the polyamide chain. That is, in this embodiment, since diamine, dicarboxylic acid, and trimesic acid are copolymerized, trimesic acid is usually incorporated into the polyamide chain. Further, although trimesic acid has three carboxylic acid groups, these carboxylic acid groups are directly bonded to the benzene ring, so the reactivity is not necessarily high. Therefore, when attempting to synthesize a polyamide resin by polycondensing diamine, dicarboxylic acid, and trimesic acid, usually, out of the three carboxylic acid groups of trimesic acid, two carboxylic acid groups react with diamine, and it is presumed that the remaining one carboxylic acid remains as a carboxylic acid group in the polyamide chain. And in this embodiment, it is presumed that the carboxylic acid groups remaining in the polyamide chain interacted, resulting in a decrease in the fluidity of the polyamide resin and an increase in the melt viscosity. As a result, it is presumed that the melt tension of the obtained polyamide resin was also improved.

[0009] In the polyamide resin of this embodiment, 50 mol% or more of the diamine is xylylenediamine, preferably 60 mol% or more, more preferably 70 mol% or more, still more preferably 80 mol% or more, even more preferably 90 mol% or more, even more preferably 94 mol% or more, and may be 96 mol% or more, 98 mol%, 99 mol% or more, or even 100 mol%. By setting it to the above lower limit value or more, the barrier property to various gases tends to be improved.

[0010] Xylylenediamine is preferably para-xylylenediamine and / or meta-xylylenediamine. It is preferred that the xylylenediamine contains 0 to 100 mol% of meta-xylylenediamine and 100 to 0 mol% of para-xylylenediamine (however, the total of meta-xylylenediamine and para-xylylenediamine does not exceed 100 mol%). More preferably, it contains 10 to 100 mol% of meta-xylylenediamine and 90 to 0 mol% of para-xylylenediamine. Even more preferably, it contains 30 to 100 mol% of meta-xylylenediamine and 70 to 0 mol% of para-xylylenediamine. Still more preferably, it contains 40 to 100 mol% of meta-xylylenediamine and 60 to 0 mol% of para-xylylenediamine. Even more preferably, it contains 60 to 100 mol% of meta-xylylenediamine and 40 to 0 mol% of para-xylylenediamine. Even more preferably, it contains 80 to 100 mol% of meta-xylylenediamine and 20 to 0 mol% of para-xylylenediamine. Particularly preferably, it contains 95 to 100 mol% of meta-xylylenediamine and 5 to 0 mol% of para-xylylenediamine. The total of para-xylylenediamine and meta-xylylenediamine that constitutes the polyamide resin of this embodiment preferably accounts for 80 mol% or more, more preferably 85 mol% or more, even more preferably 90 mol% or more, still more preferably 95 mol% or more, even more preferably 98 mol% or more, and particularly preferably 99 mol% or more of the diamine. The upper limit of the total of para-xylylenediamine and meta-xylylenediamine is 100 mol%.

[0011] In addition, examples of diamines other than xylylenediamine that constitute the polyamide resin of the present embodiment include aliphatic diamines such as tetramethylenediamine, pentamethylenediamine, 2-methylpentanediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, dodecamethylenediamine, 2,2,4-trimethyl-hexamethylenediamine, and 2,4,4-trimethylhexamethylenediamine; alicyclic diamines such as 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, 1,3-diaminocyclohexane, 1,4-diaminocyclohexane, bis(4-aminocyclohexyl)methane, 2,2-bis(4-aminocyclohexyl)propane, bis(aminomethyl)decalin, and bis(aminomethyl)tricyclodecane; and diamines having an aromatic ring such as bis(4-aminophenyl)ether, paraphenylenediamine, and bis(aminomethyl)naphthalene. One or more of these can be mixed and used.

[0012] In the polyamide resin of the present embodiment, the type of dicarboxylic acid is not particularly defined, but it is preferable that 50 mol% or more of the dicarboxylic acid is an α,ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms and / or an aromatic dicarboxylic acid, more preferably 5 to 100 mol% is an α,ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms, and 95 to 0 mol% is isophthalic acid, and even more preferably 85 to 100 mol% is an α,ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms, and 15 to 0 mol% is isophthalic acid (however, the total of the α,ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms and the aromatic dicarboxylic acid does not exceed 100 mol%).

[0013] More specifically, when the dicarboxylic acid is an α,ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms, it is preferably an α,ω-linear aliphatic dicarboxylic acid having 4 to 14 carbon atoms, more preferably any one or more of adipic acid, sebacic acid, and dodecanedioic acid, even more preferably adipic acid and / or sebacic acid, and still more preferably adipic acid.

[0014] In the polyamide resin of the present embodiment, in the first embodiment of the dicarboxylic acid, preferably 50 mol% or more, more preferably 80 mol% or more, even more preferably 90 mol% or more, still more preferably 95 mol% or more, even more preferably 98 mol% or more, and still even more preferably 99 mol% or more of the dicarboxylic acid is an α,ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms. In particular, in the first embodiment of the dicarboxylic acid, it is preferable that the α,ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms is adipic acid.

[0015] When the dicarboxylic acid is in the first embodiment, the melting point of the polyamide resin is preferably 210°C or higher, more preferably 220°C or higher, and preferably 236°C or lower, more preferably 235°C or lower.

[0016] When the dicarboxylic acid is in the first embodiment, the glass transition temperature of the polyamide resin is preferably 86°C or higher, more preferably 87°C or higher, and preferably 100°C or lower, more preferably 95°C or lower, and even more preferably 90°C or lower. The melting point and glass transition temperature of the polyamide resin when the dicarboxylic acid is in the first embodiment are measured according to the description of the examples described later (the same applies to the polyamide resin when the dicarboxylic acid is in the second embodiment and the polyamide resin when the dicarboxylic acid is in the third embodiment).

[0017] When the dicarboxylic acid is in the first embodiment, the polyamide resin has a melting temperature of 250°C and a shear rate of 121.6 s -1The melt viscosity measured according to this is preferably 510 Pa·s or more, more preferably 550 Pa·s or more, still more preferably 600 Pa·s or more, even more preferably 700 Pa·s or more, yet more preferably 750 Pa·s or more, still yet more preferably 800 Pa·s or more, and preferably 1500 Pa·s or less, more preferably 1200 Pa·s or less, still more preferably 1000 Pa·s or less.

[0018] When the dicarboxylic acid is in the first embodiment, the polyamide resin has a melt temperature of 250 °C and a shear rate of 1216 s -1 The melt viscosity measured according to this is preferably 240 Pa·s or more, more preferably 250 Pa·s or more, still more preferably 260 Pa·s or more, and preferably 500 Pa·s or less, more preferably 450 Pa·s or less, still more preferably 400 Pa·s or less, and even more preferably 350 Pa·s or less. The shear rate of the polyamide resin when the dicarboxylic acid is in the first embodiment is measured according to the description of the examples described later (the same applies to the polyamide resin when the dicarboxylic acid is in the second embodiment and the polyamide resin when the dicarboxylic acid is in the third embodiment).

[0019] In the polyamide resin of this embodiment, in the second embodiment of the dicarboxylic acid, 95 to 40 mol% is an α,ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms, and 5 to 60 mol% is preferably isophthalic acid, 60 to 40 mol% is an α,ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms, and 40 to 60 mol% is more preferably isophthalic acid, 60 to 43 mol% is an α,ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms, and 40 to 57 mol% is still more preferably isophthalic acid.

[0020] When the dicarboxylic acid is in the second embodiment, the polyamide resin is preferably an amorphous resin having no distinct melting point.

[0021] When the dicarboxylic acid is in the second embodiment, the glass transition temperature of the polyamide resin is preferably above 125 °C, more preferably 126 °C or higher, and preferably 135 °C or lower, more preferably 132 °C or lower, and even more preferably 130 °C or lower.

[0022] When the dicarboxylic acid is in the second embodiment, the polyamide resin has a melting temperature of 250 °C and a shear rate of 121.6 s -1 The melt viscosity measured according to is preferably above 125 Pa·s, more preferably 126 Pa·s or higher, and preferably 300 Pa·s or lower, more preferably 250 Pa·s or lower, even more preferably 200 Pa·s or lower, and still more preferably 150 Pa·s or lower.

[0023] When the dicarboxylic acid is in the second embodiment, the polyamide resin has a melting temperature of 250 °C and a shear rate of 1216 s -1 The melt viscosity measured according to is preferably 1720 Pa·s or higher, more preferably 1730 Pa·s or higher, even more preferably 1735 Pa·s or higher, and preferably 2000 Pa·s or lower, more preferably 1900 Pa·s or lower, and even more preferably 1800 Pa·s or lower.

[0024] In the polyamide resin of this embodiment, in the third embodiment of the dicarboxylic acid, 97 to 80 mol% is an α,ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms, and 3 to 20 mol% is preferably isophthalic acid, more preferably 97 to 85 mol% is an α,ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms, and 3 to 15 mol% is isophthalic acid, even more preferably 97 to 90 mol% is an α,ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms, and 3 to 10 mol% is isophthalic acid, and still more preferably 96 to 92 mol% is an α,ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms, and 4 to 8 mol% is isophthalic acid.

[0025] When the dicarboxylic acid is in the third embodiment, the melting point of the polyamide resin is preferably 220 °C or higher, more preferably 225 °C or higher, and preferably 229 °C or lower, more preferably 228 °C or lower.

[0026] When the dicarboxylic acid is in the third embodiment, the glass transition temperature of the polyamide resin is preferably above 92 °C, more preferably 93 °C or higher, and preferably 100 °C or lower, more preferably 95 °C or lower.

[0027] When the dicarboxylic acid is in the third embodiment, the polyamide resin has a melt viscosity of 650 Pa·s or higher, more preferably 700 Pa·s or higher, even more preferably 730 Pa·s or higher, and preferably 2000 Pa·s or lower, more preferably 1900 Pa·s or lower, even more preferably 1800 Pa·s or lower, measured according to a melt temperature of 250 °C and a shear rate of 121.6 s -1 -1.

[0028] When the dicarboxylic acid is in the third embodiment, the polyamide resin has a melt viscosity of 250 Pa·s or higher, more preferably 260 Pa·s or higher, and preferably 700 Pa·s or lower, more preferably 650 Pa·s or lower, even more preferably 600 Pa·s or lower, measured according to a melt temperature of 250 °C and a shear rate of 1216 s -1 -1.

[0029] Examples of dicarboxylic acids other than those described above include phthalic acid compounds such as terephthalic acid and orthophthalic acid, isomers of naphthalenedicarboxylic acid such as 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. One or more of them can be mixed and used. The polyamide resin of this embodiment preferably does not substantially contain terephthalic acid. "Not substantially containing" means that the proportion of terephthalic acid is less than 3% by mass of the dicarboxylic acid constituting the polyamide resin, and preferably less than 1% by mass.

[0030] The polyamide resin of this embodiment copolymerizes trimellitic acid together with diamine and dicarboxylic acid. With respect to a total of 100 mol% of the diamine, dicarboxylic acid, and trimellitic acid, trimellitic acid is 0.01 to 5 mol%. By using such a small amount of trimellitic acid, a polyamide resin with a high melt viscosity can be obtained. The proportion of the trimellitic acid is preferably 0.03 mol% or more, more preferably 0.05 mol% or more, further preferably 0.1 mol% or more, still more preferably 0.2 mol% or more. Also, it is preferably 4 mol% or less, more preferably 3.5 mol% or less, further preferably 3 mol% or less, still more preferably 2 mol% or less, and even more preferably 1.5 mol% or less. By setting it to be not less than the lower limit value, the melt tension tends to be further improved. Also, by setting it to be not more than the upper limit value, the processability during molding tends to be further improved.

[0031] The polyamide resin of the present embodiment is mainly composed of structural units derived from diamine and structural units derived from dicarboxylic acid. However, it does not completely exclude structural units other than these. Needless to say, it may contain structural units derived from lactams such as ε-caprolactam and laurolactam, and aliphatic aminocarboxylic acids such as aminocaproic acid and aminoundecanoic acid. Here, the main component means that among the structural units constituting the polyamide resin of the present embodiment, the total number of structural units derived from diamine and structural units derived from dicarboxylic acid is the largest among all the structural units. In the polyamide resin of the present embodiment, the total of the structural units derived from diamine, the structural units derived from dicarboxylic acid, and the structural units derived from trimesic acid preferably accounts for 90% by mass or more of all the structural units, more preferably 95% by mass or more, still more preferably 97% by mass or more, and even more preferably 99% by mass or more.

[0032] The polyamide resin of the present embodiment is preferably a polyamide resin (biomass polyamide resin) produced using biomass raw materials. By using a biomass polyamide resin, it is possible to reduce the environmental load. In the polyamide resin of the present embodiment, bioadipic acid can be used as the biomass raw material. Also, adipic acid certified by mass balance (ISCC PLUS) can be used. Mass balance certification means that for each factory or production facility, the extent to which renewable raw materials and bio-based raw materials are used and the extent to which products are produced and shipped are quantified and guaranteed together with the quality.

[0033] In the polyamide resin of the present embodiment, the lower limit of the number average molecular weight (Mn) is preferably 6,000 or more, more preferably 8,000 or more, still more preferably 10,000 or more, and preferably 100,000 or less, more preferably 50,000 or less. When it is in such a range, the heat resistance, elastic modulus, dimensional stability, and molding processability are better.

[0034] The polyamide resin of the present embodiment preferably has a lower limit of weight average molecular weight (Mw) of 10,000 or more, more preferably 30,000 or more, still more preferably 50,000 or more, and preferably 140,000 or less, more preferably 120,000 or less. When it is in such a range, heat resistance, elastic modulus, dimensional stability, and moldability are better. The number average molecular weight and weight average molecular weight of the polyamide resin are measured according to the description of the examples described later. The polyamide resin of the present embodiment may be a crystalline resin having a distinct melting point or an amorphous resin not showing a distinct melting point, but is preferably a crystalline resin. By being a crystalline resin, it can have high chemical resistance.

[0035] The method for producing the polyamide resin of the present embodiment includes copolymerizing a diamine, a dicarboxylic acid, and trimesic acid, wherein 50 mol% or more of the diamine is xylylenediamine, and with respect to a total of 100 mol% of the diamine, dicarboxylic acid, and trimesic acid, trimesic acid is preferably 0.01 to 5 mol%. The polyamide resin produced by the production method of the present embodiment is preferably the polyamide resin of the present embodiment described above.

[0036] The polyamide resin of the present embodiment can be produced by a known method in other respects, preferably by a melt polycondensation (melt polymerization) method or a pressure salt method using a phosphorus atom-containing compound as a catalyst, and more preferably by a melt polycondensation method. As the melt polycondensation method, a method is preferred in which the raw material diamine is dropped into the molten raw material dicarboxylic acid, the temperature is raised under pressure, and polymerization is carried out while removing the condensation water. As the pressure salt method, a method is preferred in which a salt composed of a raw material diamine and a raw material dicarboxylic acid is heated under pressure in the presence of water, and polymerization is carried out in a molten state while removing the added water and the condensation water. Also, in the present embodiment, the copolymerization (polyamide resin) of the diamine, dicarboxylic acid, and trimesic acid may be further subjected to solid-phase polymerization. By carrying out solid-phase polymerization, a polyamide resin having a higher molecular weight can be obtained.

[0037] <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 body formed from the resin composition of the present embodiment. The resin composition of the present embodiment may consist of only one or two or more kinds of the polyamide resin of the present embodiment, or may contain other components. As other components, other polyamide resins other than the polyamide resin of the present embodiment, thermoplastic resins other than polyamide resins, reinforcing materials (fillers), antioxidants such as heat stabilizers and weather stabilizers (especially heat stabilizers), flame retardants, flame retardant aids, release agents, anti-dripping agents, matting agents, ultraviolet absorbers, plasticizers, antistatic agents, anti-coloring agents, anti-gelling agents, nucleating agents and other additives can be added as necessary. Each of these additives may be one kind or two or more kinds. Details of these can incorporate the additives described in paragraphs 0047 to 0103 of International Publication No. 2021 / 241471, and this content is incorporated herein.

[0038] <Method for producing resin composition> The method for producing the resin composition of the present embodiment is not particularly defined, and a known method for producing a thermoplastic resin composition can be widely adopted. Specifically, after premixing each component using various mixers such as a tumbler and a Henschel mixer, the resin composition can be produced by melt-kneading with a Banbury mixer, a roll, a Brabender, a single-screw extruder, a twin-screw extruder, a kneader, or the like.

[0039] Alternatively, for example, the resin composition of the present embodiment can also be produced by feeding the components to an extruder using a feeder and melt-kneading them without previously mixing all the components or by previously mixing only some of the components. Further, for example, a resin composition obtained by previously mixing some of the components, feeding them to an extruder, and melt-kneading them can be used as a masterbatch, and this masterbatch can be mixed again with the remaining components and melt-kneaded to produce the resin composition of the present embodiment.

[0040] <Molded article> The molded article of the present embodiment is molded from the polyamide resin of the present embodiment or the resin composition of the present embodiment. The method for molding the molded article is not particularly limited, and a conventionally known molding method can be employed. For example, injection molding method, injection compression molding method, extrusion molding method, profile extrusion method, transfer molding method, blow molding method, gas-assisted blow molding method, blow molding method, extrusion blow molding, IMC (in-mold coating molding) molding method, rotational molding method, multilayer molding method, two-color molding method, insert molding method, sandwich molding method, foam molding method, pressure molding method, stretching, vacuum molding, etc. can be mentioned. The extrusion molding method and the foam molding method are preferable, and the extrusion molding method is more preferable. That is, since the molded article of the present embodiment has a high melt viscosity and thus a high melt tension, an extruded molded article is suitable. Examples of the molded article formed from the polyamide resin or the resin composition of the present embodiment include hollow molded articles (hoses, tubes, etc.), films (including plates and sheets), fibers, foams, etc. It is preferably a film, fiber, or foam. The foam is produced by blending a foaming agent into the polyamide resin or the resin composition and foaming the foaming agent after extrusion. At this time, if the melt tension of the polyamide resin is high, the polyamide resin can appropriately stretch in response to the foaming of the foaming agent, and a good foam can be produced.

[0041] As the molded article, in addition to those described above, pipes, gears, cams, various housings, rollers, impellers, bearing retainers, spring holders, clutch parts, chain tensioners, tanks, wheels, connectors, switches, sensors, sockets, capacitors, hard disk parts, jacks, fuse holders, relays, coil bobbins, resistors, IC housings, LED reflectors, intake pipes, blow-by tubes, base materials for 3D printers, interior and exterior automotive parts, parts in the engine room, cooling system parts, sliding parts, automotive supplies such as electrical parts, electrical and electronic parts, surface mount type connectors, sockets, camera modules, power supply parts, switches, sensors, capacitor base plates, hard disk parts, relays, resistors, fuse holders, coil bobbins, IC housings and other surface mount parts, fuel caps, fuel tanks, fuel sender modules, fuel cut-off valves, canisters, fuel pipes and other fuel system parts can be used.

Example

[0042] 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 measuring instruments and the like used in the examples are difficult to obtain due to being obsolete or the like, measurements can be made using other devices having equivalent performance.

[0043] Comparative Example 1 <Synthesis of polyamide resin> In a reaction vessel with a jacket equipped with a stirrer, a partial condenser, a cooler, a thermometer, a dropping funnel, and a nitrogen gas inlet tube, 9000 g (61.58 mol) of adipic acid and 13.3 g of sodium acetate / sodium hypophosphite monohydrate (molar ratio = 0.9 / 1.0) were charged, thoroughly purged with nitrogen, heated to 180 °C and melted. Then, while stirring the contents, 8388 g of metaxylylenediamine (61.58 mol of metaxylylenediamine, manufactured by Mitsubishi Gas Chemical Company) was added dropwise to the melt in the reaction vessel with stirring, and the temperature was raised to 240 °C while discharging the generated condensation water out of the system. After completion of the dropping, the temperature was raised to 260 °C and maintained for 20 minutes. Then, the pressure inside the reaction system was continuously reduced to 0.08 MPa, and the reaction was continued. After completion of the reaction, the inside of the reaction vessel was pressurized with nitrogen gas to 0.2 MPa, and the polymer was taken out as a strand from the nozzle at the bottom of the polymerization tank, water-cooled, and pelletized with a pelletizer to obtain polyamide MXD6. The melting point, glass transition temperature, melt viscosity, melt tension, and molecular weight (Mn, Mw) were measured. The melt viscosity and melt tension were measured after drying the obtained pellets in a vacuum dryer at 130 °C for 8 hours.

[0044] <Melting point (Tm) and glass transition temperature (Tg)> The melting point and glass transition temperature of the polyamide resin were measured by differential scanning calorimetry (DSC). The DSC measurement was carried out in accordance with JIS K7121 and K7122. Using a differential scanning calorimeter, the synthesized polyamide resin was crushed and charged into the measurement pan of the differential scanning calorimeter. The temperature was raised at a rate of 10 °C / min to the melting point (assumed value) + 20 °C under a nitrogen atmosphere. Immediately after the temperature rise was completed, the measurement pan was taken out and pressed against dry ice for rapid cooling. Then the measurement was carried out. The measurement conditions were as follows: the temperature was raised at a rate of 10 °C / min to about the melting point + 20 °C and held for 5 minutes, and then the temperature was lowered at a rate of -5 °C / min to 100 °C for measurement to determine the melting point (Tm) and glass transition temperature (Tg). As the differential scanning calorimeter, "DSC-60" manufactured by Shimadzu Corporation was used. The unit of the melting point and the unit of the glass transition temperature were shown in °C.

[0045] <Melt viscosity> The melt viscosity of the polyamide resin was measured using a capillary graph, with a die having a diameter of 1 mm and a length of 10 mm, apparent shear rates of 121.6 s -1 , 1216 s -1 , at a measurement temperature of 250 °C, a holding time of 6 minutes, and a water content of the polyamide resin of 1000 weight ppm or less. In this example, a capillary graph 1D manufactured by Toyo Seiki Seisakusho Co., Ltd. was used as the capillary graph.

[0046] <Melt Tension> The melt viscosity of the polyamide resin was measured using a capillary graph, with a die having a diameter of 2 mm and a length of 8 mm, at a measurement temperature of 250 °C, a preheating time of 6 minutes, a piston speed of 5 mm / min, and a take-up speed of 5 m / min. In this example, a capillary graph 1D manufactured by Toyo Seiki Seisakusho Co., Ltd. was used as the capillary graph.

[0047] <Weight Average Molecular Weight and Number Average Molecular Weight> The weight average molecular weight (Mw) and number average molecular weight (Mn) of the polyamide resin were determined from the standard polymethyl methacrylate (PMMA) conversion values by gel permeation chromatography (GPC) measurement. As columns, two columns filled with a styrene-based polymer as a filler were used. As the solvent, hexafluoroisopropanol (HFIP) with a sodium trifluoroacetate concentration of 2 mmol / L was used, the resin concentration was 0.02 mass%, the column temperature was 40 °C, the flow rate was 0.3 mL / min, and the measurement was performed using a refractive index detector (RI). Also, the calibration curve was measured by dissolving six levels of PMMA in HFIP.

[0048] Example 1 <Synthesis of Polyamide Resin> In a reaction vessel with a jacket equipped with a stirrer, a partial condenser, a cooler, a thermometer, a dropping tank, and a nitrogen gas inlet tube, 9000 g (61.58 mol) of adipic acid, 65.0 g (0.31 mol) of trimesic acid, and 13.4 g of sodium acetate / sodium hypophosphite monohydrate (molar ratio = 0.9 / 1.0) were charged. After sufficient nitrogen replacement, the mixture was heated to 180 °C and melted. Then, while stirring the contents, 8430 g of metaxylylenediamine (61.89 mol of metaxylylenediamine, manufactured by Mitsubishi Gas Chemical Company) was added dropwise to the melt in the reaction vessel with stirring, and the temperature was raised to 240 °C while discharging the generated condensed water out of the system. After the dropping was completed, the temperature was raised to 260 °C and maintained for 20 minutes. Then, the pressure inside the reaction system was continuously reduced to 0.08 MPa, and the reaction was continued. After the reaction was completed, the inside of the reaction vessel was pressurized with nitrogen gas to 0.2 MPa, and the polymer was taken out as a strand from the nozzle at the bottom of the polymerization tank, cooled with water, and pelletized with a pelletizer to obtain a polyamide resin. From the unreacted monomers, trimesic acid was not detected, and it was confirmed that trimesic acid was incorporated into the polyamide resin. The obtained polyamide resin was evaluated in the same manner as in Comparative Example 1.

[0049] Example 2 <Synthesis of Polyamide Resin> In a jacketed reactor equipped with a stirrer, a partial condenser, a cooler, a thermometer, a dropping tank and a nitrogen gas inlet tube, 9000 g (61.58 mol) of adipic acid, 130.7 g (0.62 mol) of trimesic acid, and 13.5 g of sodium acetate / sodium hypophosphite monohydrate (molar ratio = 0.9 / 1.0) were charged. After sufficient nitrogen substitution and heating to 180 °C for melting, while stirring the contents, 8473 g of metaxylylenediamine (62.21 mol of metaxylylenediamine, manufactured by Mitsubishi Gas Chemical Company) was added dropwise to the melt in the reaction vessel under stirring, and the temperature was raised to 240 °C while discharging the generated condensed water out of the system. After the dropping was completed, the temperature was raised to 260 °C and maintained for 20 minutes. Then, the pressure inside the reaction system was continuously reduced to 0.08 MPa, and the reaction was continued. After the reaction was completed, the inside of the reactor was pressurized with nitrogen gas to 0.2 MPa, and the polymer was taken out as a strand from the nozzle at the bottom of the polymerization tank, and after water cooling, it was pelletized with a pelletizer to obtain a polyamide resin. From the unreacted monomers, trimesic acid was not detected, and it was confirmed that trimesic acid was incorporated into the polyamide resin. The obtained polyamide resin was evaluated in the same manner as in Comparative Example 1.

[0050] Comparative Example 2 <Synthesis of Polyamide Resin> In a reaction vessel with a jacket equipped with a stirrer, a partial condenser, a cooler, a thermometer, a dropping tank, and a nitrogen gas inlet pipe, 4500 g (30.79 mol) of adipic acid, 5116 g (30.79 mol) of isophthalic acid, and 13.8 g of sodium acetate / sodium hypophosphite monohydrate (molar ratio = 0.9 / 1.0) were charged. After sufficient nitrogen substitution and heating to 190 °C to melt, while stirring the contents, 8388 g of metaxylylenediamine (61.58 mol of metaxylylenediamine, manufactured by Mitsubishi Gas Chemical Company) was added dropwise to the melt in the reaction vessel with stirring, and the temperature was raised to 250 °C while discharging the generated condensed water out of the system. After the dropping was completed, the temperature was raised to 270 °C and maintained for 20 minutes. Then, the internal pressure of the reaction system was continuously reduced to 0.08 MPa, and the reaction was continued. After the reaction was completed, the inside of the reaction vessel was pressurized with nitrogen gas to 0.2 MPa, and the polymer was taken out as a strand from the nozzle at the bottom of the polymerization tank, and after water cooling, it was pelletized with a pelletizer to obtain a polyamide resin. The obtained polyamide resin was evaluated in the same manner as in Comparative Example 1. However, since it was an amorphous polyamide resin, a clear melting point could not be measured.

[0051] Example 3 <Synthesis of Polyamide Resin> In a reaction vessel with a jacket equipped with a stirrer, a partial condenser, a cooler, a thermometer, a dropping tank, and a nitrogen gas inlet pipe, 4500 g (30.79 mol) of adipic acid, 5064 g (30.48 mol) of isophthalic acid, 64.7 g (0.31 mol) of trimesic acid, and 13.8 g of sodium acetate / sodium hypophosphite monohydrate (molar ratio = 0.9 / 1.0) were charged. After sufficient nitrogen replacement and heating to 190 °C to melt, while stirring the contents, 8388 g of metaxylylenediamine (61.58 mol of metaxylylenediamine, manufactured by Mitsubishi Gas Chemical Company) was added dropwise to the melt in the reaction vessel with stirring, and the temperature was raised to 250 °C while discharging the generated condensed water out of the system. After the dropping was completed, the temperature was raised to 270 °C and continued for 20 minutes. Then, the pressure inside the reaction system was continuously reduced to 0.08 MPa, and the reaction was continued. After the reaction was completed, the inside of the reaction vessel was pressurized with nitrogen gas to 0.2 MPa, and the polymer was taken out as a strand from the nozzle at the bottom of the polymerization tank, and after water cooling, it was pelletized with a pelletizer to obtain a polyamide resin. From the unreacted monomers, trimesic acid was not detected, and it was confirmed that trimesic acid was incorporated into the polyamide resin. The obtained polyamide resin was evaluated in the same manner as in Comparative Example 1. However, since it was an amorphous polyamide resin, a clear melting point could not be measured.

[0052] Example 4 <Synthesis of Polyamide Resin> In a reaction vessel with a jacket equipped with a stirrer, a partial condenser, a cooler, a thermometer, a dropping funnel, and a nitrogen gas inlet tube, 4500 g (30.79 mol) of adipic acid, 5013 g (30.18 mol) of isophthalic acid, 129.4 g (0.62 mol) of trimesic acid, and 13.7 g of sodium acetate / sodium hypophosphite monohydrate (molar ratio = 0.9 / 1.0) were charged. After sufficient nitrogen replacement and heating to 190 °C to melt, while stirring the contents, 8388 g of metaxylylenediamine (61.58 mol of metaxylylenediamine, manufactured by Mitsubishi Gas Chemical Company) was added dropwise to the melt in the reaction vessel under stirring, and the temperature was raised to 250 °C while discharging the generated condensed water out of the system. After the dropping was completed, the temperature was raised to 270 °C and maintained for 20 minutes. Then, the pressure inside the reaction system was continuously reduced to 0.08 MPa, and the reaction was continued. After the reaction was completed, the inside of the reaction vessel was pressurized with nitrogen gas to 0.2 MPa, and the polymer was taken out as a strand from the nozzle at the bottom of the polymerization tank, cooled with water, and pelletized with a pelletizer to obtain a polyamide resin. From the unreacted monomers, trimesic acid was not detected, and it was confirmed that trimesic acid was incorporated into the polyamide resin. The obtained polyamide resin was evaluated in the same manner as in Comparative Example 1. However, since it was an amorphous polyamide resin, a clear melting point could not be measured.

[0053] Comparative Example 3 <Synthesis of Polyamide Resin> In a jacketed reaction kettle equipped with a stirrer, a partial condenser, a cooler, a thermometer, a dropping funnel and a nitrogen gas inlet tube, 9000 g (61.58 mol) of adipic acid, 653 g (3.93 mol) of isophthalic acid, and 14.2 g of sodium acetate / sodium hypophosphite monohydrate (molar ratio = 0.9 / 1.0) were charged. After sufficient nitrogen replacement and heating to 190 °C to melt, while stirring the contents, 8923 g of metaxylylenediamine (65.52 mol of metaxylylenediamine, manufactured by Mitsubishi Gas Chemical Company) was added dropwise to the melt in the reaction vessel with stirring, and the temperature was raised to 250 °C while discharging the generated condensed water out of the system. After the dropping was completed, the temperature was raised to 270 °C and maintained for 20 minutes. Then, the internal pressure of the reaction system was continuously reduced to 0.08 MPa, and the reaction was continued. After the reaction was completed, the inside of the reaction kettle was pressurized with nitrogen gas to 0.2 MPa, and the polymer was taken out as a strand from the nozzle at the bottom of the polymerization tank, and after water cooling, it was pelletized with a pelletizer to obtain a polyamide resin. The obtained polyamide resin was evaluated in the same manner as in Comparative Example 1.

[0054] Example 5 <Synthesis of Polyamide Resin> In a jacketed reaction kettle equipped with a stirrer, a partial condenser, a cooler, a thermometer, a dropping funnel and a nitrogen gas inlet tube, 9000 g (61.58 mol) of adipic acid, 599 g (3.60 mol) of isophthalic acid and 68.0 g (0.33 mol) of trimesic acid, and 14.2 g of sodium acetate / sodium hypophosphite monohydrate (molar ratio = 0.9 / 1.0) were charged. After sufficient nitrogen replacement and heating to 190 °C to melt, while stirring the contents, 8923 g of metaxylylenediamine (65.52 mol of metaxylylenediamine, manufactured by Mitsubishi Gas Chemical Company) was added dropwise to the melt in the reaction vessel with stirring, and the temperature was raised to 250 °C while discharging the generated condensed water out of the system. After the dropping was completed, the temperature was raised to 270 °C and maintained for 20 minutes. Then, the internal pressure of the reaction system was continuously reduced to 0.08 MPa, and the reaction was continued. After the reaction was completed, the inside of the reaction kettle was pressurized with nitrogen gas to 0.2 MPa, and the polymer was taken out as a strand from the nozzle at the bottom of the polymerization tank, and after water cooling, it was pelletized with a pelletizer to obtain a polyamide resin. Trimellitic acid was not detected in the unreacted monomers, and it was confirmed that trimellitic acid was incorporated into the polyamide resin. The obtained polyamide resin was evaluated in the same manner as in Comparative Example 1.

[0055] Example 6 <Synthesis of Polyamide Resin> In a reaction vessel with a jacket equipped with a stirrer, a partial condenser, a cooler, a thermometer, a dropping tank, and a nitrogen gas inlet tube, 9000 g (61.58 mol) of adipic acid, 544 g (3.28 mol) of isophthalic acid, 138.0 g (0.66 mol) of trimellitic acid, and 14.2 g of sodium acetate / sodium hypophosphite monohydrate (molar ratio = 0.9 / 1.0) were charged. After sufficient nitrogen substitution and heating to 190 °C to melt, while stirring the contents, 8923 g of metaxylylenediamine (65.52 mol of metaxylylenediamine, manufactured by Mitsubishi Gas Chemical Company) was added dropwise to the melt in the reaction vessel with stirring, and the temperature was raised to 250 °C while discharging the generated condensation water out of the system. After the dropping was completed, the temperature was raised to 270 °C and maintained for 20 minutes. Then, the internal pressure of the reaction system was continuously reduced to 0.08 MPa, and the reaction was continued. After the reaction was completed, the inside of the reaction vessel was pressurized with nitrogen gas to 0.2 MPa, and the polymer was taken out as a strand from the nozzle at the bottom of the polymerization tank, cooled with water, and pelletized with a pelletizer to obtain a polyamide resin. Trimellitic acid was not detected in the unreacted monomers, and it was confirmed that trimellitic acid was incorporated into the polyamide resin. The obtained polyamide resin was evaluated in the same manner as in Comparative Example 1.

[0056]

Table 1

Table 2

[0057] Reference Example 1 For polyamide MXD6 (manufactured by Mitsubishi Gas Chemical Company, S6001) synthesized from metaxylylenediamine and adipic acid, the melting point, glass transition temperature, and melt viscosity were measured in the same manner as in Comparative Example 1.

[0058] Reference Example 2 Polyamide MXD6 (manufactured by Mitsubishi Gas Chemical Company, S6001) synthesized from metaxylylenediamine and adipic acid and trimesic acid were weighed as shown in Table 3 (the unit of each component is parts by mass), blended in a tumbler, and charged from the root of a twin-screw extruder (manufactured by Shibaura Machine Co., Ltd., TEM26SS), melt-kneaded, and pellets of the resin composition were produced. The temperature setting of the twin-screw extruder was 280°C. For the resin composition, the melting point, glass transition temperature, and melt viscosity were measured in the same manner as in Comparative Example 1.

[0059] Reference Example 3 Polyamide MXD6 (manufactured by Mitsubishi Gas Chemical Company, S6001) synthesized from metaxylylenediamine and adipic acid and trimesic acid were weighed as shown in Table 3 (the unit of each component is parts by mass), blended in a tumbler, and charged from the root of a twin-screw extruder (manufactured by Shibaura Machine Co., Ltd., TEM26SS), melt-kneaded, and pellets of the resin composition were produced. The temperature setting of the twin-screw extruder was 280°C. For the resin composition, the melting point, glass transition temperature, and melt viscosity were measured in the same manner as in Comparative Example 1.

[0060]

Table 3

[0061] As is clear from the above results, the polyamide resin of the present embodiment had a high melt viscosity and a high melt tension (Examples 1 to 6). In contrast, when trimesic acid was not included (Comparative Examples 1 to 3), the melt viscosity was low and the melt tension was also low. Also, when trimesic acid was blended into the polyamide resin and melt-kneaded (Reference Example 2, Reference Example 3), the result was that the melt viscosity was lower when trimesic acid was blended.

Claims

1. It is a copolymer of diamine, dicarboxylic acid, and trimesic acid, At least 50 mol % of the diamine is xylylenediamine; The polyamide resin contains 0.01 to 5 mol % of trimesic acid relative to 100 mol % in total of the diamine, dicarboxylic acid and trimesic acid.

2. 2. The polyamide resin according to claim 1, wherein 50 mol % or more of the dicarboxylic acids are α,ω-straight-chain aliphatic dicarboxylic acids and / or aromatic dicarboxylic acids having 4 to 20 carbon atoms.

3. 2. The polyamide resin according to claim 1, wherein 5 to 100 mol % of the dicarboxylic acid is an α,ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms, and 95 to 0 mol % is isophthalic acid.

4. 2. The polyamide resin according to claim 1, wherein 60 to 40 mol % of the dicarboxylic acid is an α,ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms, and 40 to 60 mol % is isophthalic acid.

5. 2. The polyamide resin according to claim 1, wherein 97 to 80 mol % of the dicarboxylic acid is an α,ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms, and 3 to 20 mol % is isophthalic acid.

6. The polyamide resin according to any one of claims 1 to 5, wherein 5 to 100 mol% of the dicarboxylic acid is at least one of adipic acid, sebacic acid, and dodecanedioic acid.

7. The polyamide resin was melted at a temperature of 250° C. and a shear rate of 121.6 s －１ The polyamide resin according to any one of claims 1 to 5, having a melt viscosity of 510 Pa·s or more as measured according to

8. A resin composition comprising the polyamide resin according to any one of claims 1 to 5.

9. A molded article formed from a resin composition comprising the polyamide resin according to any one of claims 1 to 5.

10. The molded article according to claim 9, which is an extrusion molded article.

11. The molded article according to claim 9, which is a film, a fiber, or a foam.

12. Copolymerizing a diamine, a dicarboxylic acid, and trimesic acid, At least 50 mol % of the diamine is xylylenediamine; The method for producing a polyamide resin, wherein the trimesic acid is 0.01 to 5 mol % relative to 100 mol % in total of the diamine, dicarboxylic acid and trimesic acid.

13. The method for producing a polyamide resin, wherein the polyamide resin is the polyamide resin according to any one of claims 1 to 5.

14. A method for producing a molded article, comprising extrusion molding the resin composition according to claim 8.

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