WO2025094683A1 - Polyamide resin, resin composition, molded article, method for producing polyamide resin, and method for producing molded article - Google Patents

Abstract

The present invention provides a polyamide resin, a resin composition, a molded article, a method for producing a polyamide resin, and a method for producing a molded article. Provided is a polyamide resin which is a copolymer of a diamine, dicarboxylic acid, and trimesic acid, wherein not less than 50 mol% of the diamine is a xylylenediamine, and the trimesic acid is 0.01-5 mol% with respect to 100 mol% of the total of the diamine, the dicarboxylic acid and the trimesic acid.

Description

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

The present invention relates to a polyamide resin, a resin composition, a molded body, a method for producing a polyamide resin, and a method for producing a molded body.

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

JP 2015-117316 A

The resin composition described in the above-mentioned Patent Document 1 is a polyamide resin synthesized from metaxylylenediamine and sebacic acid, and is capable of providing a molded article having excellent toughness while maintaining the tensile modulus that the resin inherently has.
However, such resin compositions have a low melt viscosity, and there is a demand for different polyamide resins or resin compositions that are suitable for use in cases where extrusion molding or the like is carried out.
The present invention aims to solve the above problems, and 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.

In view of the above-mentioned problems, the present inventors have conducted research and found that the above-mentioned problems can be solved by forming a copolymer of a diamine such as xylylenediamine, a dicarboxylic acid, and trimesic acid. Specifically, the above-mentioned problems have been solved by the following means.
<1> A copolymer of a diamine, a 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> The polyamide resin according to <1>, wherein 50 mol % or more of the dicarboxylic acids are α,ω-linear aliphatic dicarboxylic acids and/or aromatic dicarboxylic acids having 4 to 20 carbon atoms.
<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> The polyamide resin according to any one of <1> to <5>, wherein 5 to 100 mol % of the dicarboxylic acid is one or more of adipic acid, sebacic acid, and dodecanedioic acid.
<7> The polyamide resin according to any one of <1> to <6>, wherein the polyamide resin has a melt viscosity of 510 Pa·s or more as measured at a melting temperature of 250° C. and a shear rate of 121.6 ^{s −1.}
<8> A resin composition comprising the polyamide resin according to any one of <1> to <7>.
<9> A molded article formed from a resin composition containing the polyamide resin according to any one of <1> to <7>.
<10> The molded article according to <9>, which is an extrusion molded article.
<11> The molded article according to <9> or <10>, which is a film, a fiber, or a foam.
<12> A method for producing a copolymer of 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> A 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 product, comprising extrusion molding the resin composition according to <8>.

The present invention makes it possible to provide a polyamide resin with 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.

Hereinafter, an embodiment of 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 the present embodiment.
In this specification, the word "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 measurement methods, etc. described in the standards shown in this specification vary from year to year, they will be based on the standards as of January 1, 2023, unless otherwise specified.

The polyamide resin of the present embodiment is a copolymer of diamine, dicarboxylic acid, and trimesic acid, and is characterized in that 50 mol % or more of the diamine is xylylenediamine, and the trimesic acid is 0.01 to 5 mol % relative to 100 mol % in total of the diamine, dicarboxylic acid, and trimesic acid. By adopting such a constitution, it is possible to provide a polyamide resin having a high melt viscosity.
The present inventors have conducted an investigation of the above-mentioned Patent Document 1, and have found that in Patent Document 1, trimesic acid and a specific polyamide resin are melt-kneaded, but in this method, trimesic acid does not react with the polyamide resin, as shown in the examples of Patent Document 1. In such a resin composition containing a polyamide resin and trimesic acid, trimesic acid plays a role similar to a plasticizer, and is excellent in injection molding, but is not necessarily suitable for extrusion molding, which requires 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. In addition, trimesic acid has three carboxylic acid groups, but these carboxylic acid groups are directly bonded to benzene rings, so it cannot be said that it is highly reactive. Therefore, when polyamide resin is synthesized by polycondensing diamine, dicarboxylic acid, and trimesic acid, it is presumed that two of the three carboxylic acid groups of trimesic acid usually react with diamine, and 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 interact with each other, lowering the fluidity of the polyamide resin and increasing the melt viscosity. As a result, it is presumed that the melt tension of the obtained polyamide resin is also improved.

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, even more preferably 80 mol% or more, even more preferably 90 mol% or more, even more preferably 94 mol% or more, and may be 96 mol% or more, 98 mol%, 99 mol% or more, or may be 100 mol%. By making it above the lower limit, the barrier properties against various gases tend to be improved.

The xylylenediamine is preferably paraxylylenediamine and/or metaxylylenediamine. The xylylenediamine preferably contains 0 to 100 mol % metaxylylenediamine and 100 to 0 mol % paraxylylenediamine (however, the total of metaxylylenediamine and paraxylylenediamine does not exceed 100 mol %), more preferably contains 10 to 100 mol % metaxylylenediamine and 90 to 0 mol % paraxylylenediamine, even more preferably contains 30 to 100 mol % metaxylylenediamine and 70 to 0 mol % paraxylylenediamine, and 4 It is more preferable that it contains 0 to 100 mol% metaxylylenediamine and 60 to 0 mol% paraxylylenediamine, even more preferable that it contains 60 to 100 mol% metaxylylenediamine and 40 to 0 mol% paraxylylenediamine, even more preferable that it contains 80 to 100 mol% metaxylylenediamine and 20 to 0 mol% paraxylylenediamine, and particularly preferable that it contains 95 to 100 mol% metaxylylenediamine and 5 to 0 mol% paraxylylenediamine.
In the diamine constituting the polyamide resin of the present embodiment, the total of paraxylylenediamine and metaxylylenediamine preferably accounts for 80 mol % or more of the diamine, more preferably 85 mol % or more, even more preferably 90 mol % or more, still more preferably 95 mol % or more, still more preferably 98 mol % or more, and still more preferably 99 mol % or more. The upper limit of the total of paraxylylenediamine and metaxylylenediamine is 100 mol %.

In addition, examples of diamines other than xylylenediamine that constitute the polyamide resin of this embodiment include aliphatic diamines such as tetramethylenediamine, pentamethylenediamine, 2-methylpentanediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, dodecamethylenediamine, 2,2,4-trimethylhexamethylenediamine, and 2,4,4-trimethylhexamethylenediamine, 1,3-bis(aminomethyl)cyclohexane, and 1,3-bis(aminomethyl)cyclohexane. Examples of such diamines include alicyclic diamines such as 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. These can be used alone or in combination of two or more kinds.

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

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

In the polyamide resin of this embodiment, the first embodiment of the dicarboxylic acid is preferably 50 mol% or more, more preferably 80 mol% or more, even more preferably 90 mol% or more, even more preferably 95 mol% or more, even more preferably 98 mol% or more, and even more preferably 99 mol% or more of the dicarboxylic acid is an α,ω-straight-chain 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-straight-chain aliphatic dicarboxylic acid having 4 to 20 carbon atoms is adipic acid.

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

When the dicarboxylic acid is the first embodiment, the glass transition temperature of the polyamide resin is preferably 86° C. or higher, more preferably 87° C. or higher, and is 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 the first embodiment are measured according to the description in the Examples described below (the same applies to the polyamide resin when the dicarboxylic acid is the second embodiment and the polyamide resin when the dicarboxylic acid is the third embodiment).

When the dicarboxylic acid is the first embodiment, the polyamide resin has a melt viscosity measured at a melting temperature of 250° C. and a shear rate of 121.6 ^{s −1} of preferably 510 Pa·s or more, more preferably 550 Pa·s or more, even more preferably 600 Pa·s or more, even more preferably 700 Pa·s or more, even more preferably 750 Pa·s or more, even more preferably 800 Pa·s or more, and preferably 1500 Pa·s or less, more preferably 1200 Pa·s or less, and even more preferably 1000 Pa·s or less.

When the dicarboxylic acid is the first embodiment, the polyamide resin preferably has a melt viscosity measured at a melting temperature of 250° C. and a shear rate of 1216 s ⁻¹ of 240 Pa·s or more, more preferably 250 Pa·s or more, and even more preferably 260 Pa·s or more, and preferably 500 Pa·s or less, more preferably 450 Pa·s or less, even 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 the first embodiment is measured according to the description in the Examples below (the same applies to the polyamide resin when the dicarboxylic acid is the second embodiment and the polyamide resin when the dicarboxylic acid is the third embodiment).

In the polyamide resin of this embodiment, the second embodiment of the dicarboxylic acid is preferably 95 to 40 mol% α,ω-straight-chain aliphatic dicarboxylic acid having 4 to 20 carbon atoms and 5 to 60 mol% is isophthalic acid, more preferably 60 to 40 mol% α,ω-straight-chain aliphatic dicarboxylic acid having 4 to 20 carbon atoms and 40 to 60 mol% isophthalic acid, and even more preferably 60 to 43 mol% α,ω-straight-chain aliphatic dicarboxylic acid having 4 to 20 carbon atoms and 40 to 57 mol% isophthalic acid.

When the dicarboxylic acid is the second embodiment, the polyamide resin is preferably an amorphous resin that does not have a distinct melting point.

When the dicarboxylic acid is the second embodiment, the glass transition temperature of the polyamide resin is preferably greater than 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.

When the dicarboxylic acid is the second embodiment, the polyamide resin preferably has a melt viscosity measured at a melting temperature of 250° C. and a shear rate of 121.6 ^{s −1} of more than 125 Pa·s, more preferably 126 Pa·s or more, and preferably 300 Pa·s or less, more preferably 250 Pa·s or less, even more preferably 200 Pa·s or less, and even more preferably 150 Pa·s or less.

In the case where the dicarboxylic acid is the second embodiment, the polyamide resin has a melt viscosity measured at a melting temperature of 250° C. and a shear rate of 1216 s ⁻¹ of preferably 1720 Pa·s or more, more preferably 1730 Pa·s or more, and even more preferably 1735 Pa·s or more, and preferably 2000 Pa·s or less, more preferably 1900 Pa·s or less, and even more preferably 1800 Pa·s or less.

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

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

When the dicarboxylic acid is the third embodiment, the glass transition temperature of the polyamide resin is preferably greater than 92°C, more preferably 93°C or higher, and is preferably 100°C or lower, more preferably 95°C or lower.

In the case where the dicarboxylic acid is the third embodiment, the polyamide resin has a melt viscosity measured at a melting temperature of 250° C. and a shear rate of 121.6 ^s-1 of preferably 650 Pa·s or more, more preferably 700 Pa·s or more, and even more preferably 730 Pa·s or more, and preferably 2000 Pa·s or less, more preferably 1900 Pa·s or less, and even more preferably 1800 Pa·s or less.

When the dicarboxylic acid is the third embodiment, the polyamide resin preferably has a melt viscosity measured at a melting temperature of 250° C. and a shear rate of 1216 s ⁻¹ of 250 Pa·s or more, more preferably 260 Pa·s or more, and preferably 700 Pa·s or less, more preferably 650 Pa·s or less, and even more preferably 600 Pa·s or less.

Examples of dicarboxylic acids other than the above include phthalic acid compounds such as terephthalic acid and orthophthalic acid, and 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. These can be used alone or in combination of two or more kinds.
The polyamide resin of the present embodiment is preferably substantially free of terephthalic acid. Substantially free means that the proportion of terephthalic acid is less than 3 mass % of the dicarboxylic acid constituting the polyamide resin, and is preferably less than 1 mass %.

In the polyamide resin of the present embodiment, trimesic acid is copolymerized with diamine and dicarboxylic acid, and the amount of trimesic acid is 0.01 to 5 mol % relative to 100 mol % in total of the diamine, dicarboxylic acid, and trimesic acid. By using such a small amount of trimesic acid, a polyamide resin with high melt viscosity can be obtained.
The proportion of trimesic acid is preferably 0.03 mol% or more, more preferably 0.05 mol% or more, even more preferably 0.1 mol% or more, and even more preferably 0.2 mol% or more, and is preferably 4 mol% or less, more preferably 3.5 mol% or less, even more preferably 3 mol% or less, even more preferably 2 mol% or less, and even more preferably 1.5 mol% or less. By making it equal to or more than the lower limit, the melt tension tends to be improved. Also, by making it equal to or less than the upper limit, the processability during molding tends to be improved.

The polyamide resin of this embodiment is mainly composed of diamine-derived structural units and dicarboxylic acid-derived structural units, but does not completely exclude other structural units, and may, of course, 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 term "main component" means that, among the structural units constituting the polyamide resin of this embodiment, the total number of diamine-derived structural units and dicarboxylic acid-derived structural units is the largest among all structural units. In the polyamide resin of this embodiment, the total of the diamine-derived structural units, dicarboxylic acid-derived structural units, and trimesic acid-derived structural units preferably accounts for 90% by mass or more of all structural units, more preferably accounts for 95% by mass or more, even more preferably accounts for 97% by mass or more, and even more preferably accounts for 99% by mass or more.

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

The polyamide resin of this embodiment preferably has a lower limit of number average molecular weight (Mn) of 6,000 or more, more preferably 8,000 or more, and even more preferably 10,000 or more, and preferably 100,000 or less, and more preferably 50,000 or less. Within such ranges, the heat resistance, elastic modulus, dimensional stability, and moldability are improved.

The polyamide resin of the present embodiment has a lower limit of the weight average molecular weight (Mw) of preferably 10,000 or more, more preferably 30,000 or more, and even more preferably 50,000 or more, and is preferably 140,000 or less, and more preferably 120,000 or less. When the Mw is within such a range, the heat resistance, elastic modulus, dimensional stability, and moldability are improved.
The number average molecular weight and weight average molecular weight of the polyamide resin are measured according to the description in the Examples section below.
The polyamide resin of the present embodiment may be a crystalline resin having a clear melting point or an amorphous resin not having a clear melting point, but is preferably a crystalline resin. By being a crystalline resin, it is possible to have high chemical resistance.

The method for producing a polyamide resin of this embodiment includes copolymerizing a diamine, a dicarboxylic acid, and trimesic acid, and it is preferable that 50 mol% or more of the diamine is xylylenediamine, and that the trimesic acid is 0.01 to 5 mol% relative to a total of 100 mol% of the diamine, dicarboxylic acid, and trimesic acid. The polyamide resin produced by the production method of this embodiment is preferably the polyamide resin of this embodiment described above.

The polyamide resin of the present embodiment can be produced by a known method except for the above points, and is preferably produced by melt polycondensation (melt polymerization) method or pressurized salt method using a phosphorus atom-containing compound as a catalyst, and more preferably produced by melt polycondensation method. As the melt polycondensation method, a method is preferred in which a raw material diamine is dropped into a molten raw material dicarboxylic acid, the temperature is raised under pressure, and the condensation water is removed while the polymerization is carried out. As the pressurized salt method, a method is preferred in which a salt composed of raw material diamine and raw material dicarboxylic acid is heated under pressure in the presence of water, and the salt is polymerized in a molten state while the added water and condensation water are removed.
In this embodiment, the copolymer (polyamide resin) of the diamine, dicarboxylic acid, and trimesic acid may be further subjected to solid-state polymerization, which allows a polyamide resin having a higher molecular weight to be obtained.

<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 of the polyamide resins of the present embodiment, or may contain other components.
As other components, additives such as polyamide resins other than the polyamide resin of this embodiment, thermoplastic resins other than polyamide resins, reinforcing materials (fillers), antioxidants such as heat stabilizers and weather stabilizers (particularly heat stabilizers), flame retardants, flame retardant assistants, release agents, anti-dripping agents, matting agents, UV absorbers, plasticizers, antistatic agents, coloring inhibitors, anti-gelling agents, nucleating agents, etc. may be added as necessary. Each of these additives may be one type or two or more types.
These details can be formulated with additives described in paragraphs 0047 to 0103 of WO 2021/241471, the contents of which are incorporated herein by reference.

<Method of producing resin composition>
The method for producing the resin composition of the present 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 mixing the components in advance using various mixers such as a tumbler or a Henschel mixer, and then melt-kneading the components using a Banbury mixer, a roll, a Brabender, a single-screw extruder, a twin-screw extruder, a kneader, or the like.

Also, for example, the resin composition of this embodiment can be produced without mixing the components in advance, or by mixing only some of the components in advance and feeding the mixture to an extruder using a feeder and melt-kneading it. Furthermore, for example, the resin composition obtained by mixing some of the components in advance and feeding the mixture to an extruder and melt-kneading it can be used as a master batch, and the master batch can be mixed again with the remaining components and melt-kneaded to produce the resin composition of this embodiment.

<Molded body>
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 body is not particularly limited, and a conventionally known molding method can be adopted, for example, injection molding, injection compression molding, extrusion molding, profile extrusion, transfer molding, hollow molding, gas-assisted hollow molding, blow molding, extrusion blow molding, IMC (in-mold coating molding) molding, rotational molding, multi-layer molding, two-color molding, insert molding, sandwich molding, foam molding, pressure molding, stretching, vacuum molding, etc., and extrusion molding and foam molding are preferred, and extrusion molding is more preferred. That is, the molded body of this embodiment has a high melt viscosity and therefore a high melt tension, so that an extrusion molded body is suitable.
Examples of molded articles formed from the polyamide resin of this embodiment or the resin composition of this embodiment include hollow molded articles (hoses, tubes, etc.), films (including plate-like and sheet-like articles), fibers, and foams, and films, fibers, or foams are preferred.
A foam is produced by blending a blowing agent with a polyamide resin or a resin composition, extruding the mixture, and then foaming the blowing agent. If the polyamide resin has a high melt tension at this time, the polyamide resin will stretch appropriately in response to the foaming of the blowing agent, and a good foam can be produced.

In addition to the above, the molded articles can be used for pipes, gears, cams, various housings, rollers, impellers, bearing retainers, spring holders, clutch parts, chain tensioners, tanks, wheels, connectors, switches, sensors, sockets, capacitors, hard disk parts, jacks, fuse holders, relays, coil bobbins, resistors, IC housings, LED reflectors, intake pipes, blow-by tubes, 3D printer substrates, automotive interior and exterior parts, engine room parts, cooling system parts, sliding parts, electrical parts and other automotive products, electrical and electronic parts, surface-mounted connectors, sockets, camera modules, power supply parts, switches, sensors, capacitor base plates, hard disk parts, relays, resistors, fuse holders, coil bobbins, IC housings and other surface-mounted parts, fuel caps, fuel tanks, fuel sender modules, fuel cut-off valves, canisters, fuel pipes and other fuel system parts.

The present invention will be described in more detail below with reference to examples. The materials, amounts, ratios, processing contents, 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.
If the measuring instruments used in the examples are difficult to obtain due to discontinuation or the like, measurements can be made using other instruments with equivalent performance.

Comparative Example 1
<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, 9000g (61.58mol) of adipic acid and 13.3g of sodium acetate/sodium hypophosphite monohydrate (molar ratio = 0.9/1.0) were charged, and the contents were fully replaced with nitrogen, and after heating and melting at 180 ° C., 8388g of metaxylylenediamine (61.58mol of metaxylylenediamine, manufactured by Mitsubishi Gas Chemical Co., Ltd.) was dropped into the melt in the reactor while stirring the contents, and the temperature was raised to 240 ° C. while discharging the generated condensed water out of the system. After the dropwise addition, the temperature was raised to 260 ° C. and continued for 20 minutes. Thereafter, 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 at 0.2 MPa, and the polymer was taken out as a strand from a nozzle at the bottom of the polymerization tank, cooled with water, 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.

<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 performed in accordance with JIS K7121 and K7122. Using a differential scanning calorimeter, the synthesized polyamide resin was crushed and placed in the measurement pan of the differential scanning calorimeter, and the temperature was raised to the melting point (assumed value) +20°C at a heating rate of 10°C/min under a nitrogen atmosphere. Immediately after the heating was completed, the measurement pan was removed and pressed against dry ice to rapidly cool. Then, the measurement was performed. The measurement conditions were heating to about melting point +20°C at a heating rate of 10°C/min and held for 5 minutes, and then measuring to 100°C at a cooling rate of -5°C/min to obtain the melting point (Tm) and glass transition temperature (Tg).
The differential scanning calorimeter used was a "DSC-60" manufactured by Shimadzu Corporation.
The melting points and glass transition temperatures are shown in °C.

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

<Melt tension>
The melt viscosity of the polyamide resin was measured using a Capillograph with a die having a diameter of 2 mm and a length of 8 mm under conditions of 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 embodiment, a Capillograph 1D manufactured by Toyo Seiki Seisakusho Co., Ltd. was used as the Capillograph.

<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 measured by gel permeation chromatography (GPC) and calculated based on the standard polymethyl methacrylate (PMMA) value. As the column, two columns filled with styrene polymers were used as the packing material, and hexafluoroisopropanol (HFIP) with a sodium trifluoroacetate concentration of 2 mmol/L was used as the solvent, with a resin concentration of 0.02 mass%, a column temperature of 40°C, a flow rate of 0.3 mL/min, and a refractive index detector (RI) were used. In addition, the calibration curve was measured by dissolving six levels of PMMA in HFIP.

Example 1
<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, 9000g (61.58mol) of adipic acid, 65.0g (0.31mol) of trimesic acid, 13.4g of sodium acetate/sodium hypophosphite monohydrate (molar ratio = 0.9/1.0) were charged, and the contents were fully replaced with nitrogen, and after heating and melting at 180 ° C., 8430g of metaxylylenediamine (61.89mol of metaxylylenediamine, manufactured by Mitsubishi Gas Chemical Co., Ltd.) was dropped into the melt in the reactor while stirring the contents, and the temperature was raised to 240 ° C. while discharging the generated condensed water out of the system. After the dropwise addition, the temperature was raised to 260 ° C. and continued for 20 minutes. Thereafter, 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 to 0.2 MPa with nitrogen gas, and the polymer was taken out as strands from a nozzle at the bottom of the polymerization vessel. After cooling with water, the polymer was pelletized with a pelletizer to obtain a polyamide resin.
No trimesic acid was detected in the unreacted monomers, confirming that trimesic acid was incorporated into the polyamide resin.
The obtained polyamide resin was evaluated in the same manner as in Comparative Example 1.

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, 9000g (61.58mol) of adipic acid, 130.7g (0.62mol) of trimesic acid, and 13.5g of sodium acetate/sodium hypophosphite monohydrate (molar ratio = 0.9/1.0) were charged, and the contents were fully replaced with nitrogen, and the mixture was heated and melted at 180°C. While stirring the contents, 8473g of metaxylylenediamine (62.21mol of metaxylylenediamine, manufactured by Mitsubishi Gas Chemical Co., Ltd.) was added dropwise to the melt in the reactor under stirring, and the temperature was raised to 240°C while discharging the generated condensed water out of the system. After the dropwise addition, the temperature was raised to 260°C and continued for 20 minutes. Thereafter, the pressure inside the reaction system was continuously reduced to 0.08MPa, and the reaction was continued. After the reaction was completed, the inside of the reactor was pressurized to 0.2 MPa with nitrogen gas, and the polymer was taken out as a strand from a nozzle at the bottom of the polymerization vessel, cooled with water, and pelletized with a pelletizer to obtain a polyamide resin. No trimesic acid was detected in the unreacted monomers, 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.

Comparative 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, 4500g (30.79mol) of adipic acid, 5116g (30.79mol) of isophthalic acid, 13.8g of sodium acetate/sodium hypophosphite monohydrate (molar ratio = 0.9/1.0) were charged, and the contents were fully replaced with nitrogen, and after heating and melting at 190 ° C., 8388g of metaxylylenediamine (61.58mol of metaxylylenediamine, manufactured by Mitsubishi Gas Chemical Co., Ltd.) was dropped into the melt in the reactor while stirring, and the temperature was raised to 250 ° C. while discharging the generated condensed water out of the system. After the dropwise addition, the temperature was raised to 270 ° C. and continued for 20 minutes. Thereafter, 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 to 0.2 MPa with nitrogen gas, and the polymer was taken out as strands from a nozzle at the bottom of the polymerization vessel. After cooling with water, the polymer 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, the melting point could not be measured clearly.

Example 3
<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, 4500g (30.79mol) of adipic acid, 5064g (30.48mol) of isophthalic acid, 64.7g (0.31mol) of trimesic acid, 13.8g of sodium acetate/sodium hypophosphite monohydrate (molar ratio = 0.9/1.0) were charged, and the contents were fully replaced with nitrogen, and after heating and melting at 190 ° C., 8388g of metaxylylenediamine (61.58mol of metaxylylenediamine, manufactured by Mitsubishi Gas Chemical Co., Ltd.) was dropped into the melt in the reactor while stirring, and the temperature was raised to 250 ° C. while discharging the generated condensed water out of the system. After the dropwise addition, the temperature was raised to 270 ° C. and continued for 20 minutes. Thereafter, 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 to 0.2 MPa with nitrogen gas, and the polymer was taken out as strands from a nozzle at the bottom of the polymerization vessel. After cooling with water, the polymer was pelletized with a pelletizer to obtain a polyamide resin.
No trimesic acid was detected in the unreacted monomers, confirming 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, the melting point could not be measured clearly.

Example 4
<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, 4500g (30.79mol) of adipic acid, 5013g (30.18mol) of isophthalic acid, 129.4g (0.62mol) of trimesic acid, 13.7g of sodium acetate/sodium hypophosphite monohydrate (molar ratio = 0.9/1.0) were charged, and the contents were fully replaced with nitrogen, and after heating and melting at 190 ° C., 8388g of metaxylylenediamine (61.58mol of metaxylylenediamine, manufactured by Mitsubishi Gas Chemical Co., Ltd.) was dropped into the melt in the reactor while stirring, and the temperature was raised to 250 ° C. while discharging the generated condensed water out of the system. After the dropwise addition, the temperature was raised to 270 ° C. and continued for 20 minutes. Thereafter, 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 to 0.2 MPa with nitrogen gas, and the polymer was taken out as strands from a nozzle at the bottom of the polymerization vessel. After cooling with water, the polymer was pelletized with a pelletizer to obtain a polyamide resin.
No trimesic acid was detected in the unreacted monomers, confirming 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, the melting point could not be measured clearly.

Comparative Example 3
<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, 9000g (61.58mol) of adipic acid, 653g (3.93mol) of isophthalic acid, 14.2g of sodium acetate/sodium hypophosphite monohydrate (molar ratio = 0.9/1.0) were charged, and the contents were fully replaced with nitrogen, and after heating and melting at 190 ° C., 8923g of metaxylylenediamine (65.52mol of metaxylylenediamine, manufactured by Mitsubishi Gas Chemical Co., Ltd.) was dropped into the melt in the reactor while stirring the contents, and the temperature was raised to 250 ° C. while discharging the generated condensed water out of the system. After the dropwise addition, the temperature was raised to 270 ° C. and continued for 20 minutes. Thereafter, 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 to 0.2 MPa with nitrogen gas, and the polymer was taken out as strands from a nozzle at the bottom of the polymerization vessel. After cooling with water, the polymer 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.

Example 5
<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, 9000g (61.58mol) of adipic acid, 599g (3.60mol) of isophthalic acid, 68.0g (0.33mol) of trimesic acid, 14.2g of sodium acetate/sodium hypophosphite monohydrate (molar ratio = 0.9/1.0) were charged, and the contents were fully replaced with nitrogen, and after heating and melting at 190 ° C., 8923g of metaxylylenediamine (65.52mol of metaxylylenediamine, manufactured by Mitsubishi Gas Chemical Co., Ltd.) was dropped into the melt in the reactor while stirring, and the temperature was raised to 250 ° C. while discharging the generated condensed water out of the system. After the dropwise addition, the temperature was raised to 270 ° C. and continued for 20 minutes. Thereafter, 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 to 0.2 MPa with nitrogen gas, and the polymer was taken out as strands from a nozzle at the bottom of the polymerization vessel. After cooling with water, the polymer was pelletized with a pelletizer to obtain a polyamide resin.
No trimesic acid was detected in the unreacted monomers, confirming that trimesic acid was incorporated into the polyamide resin.
The obtained polyamide resin was evaluated in the same manner as in Comparative Example 1.

Example 6
<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, 9000g (61.58mol) of adipic acid, 544g (3.28mol) of isophthalic acid, 138.0g (0.66mol) of trimesic acid, 14.2g of sodium acetate/sodium hypophosphite monohydrate (molar ratio = 0.9/1.0) were charged, and the contents were fully replaced with nitrogen, and after heating and melting at 190 ° C., 8923g of metaxylylenediamine (65.52mol of metaxylylenediamine, manufactured by Mitsubishi Gas Chemical Co., Ltd.) was dropped into the melt in the reactor while stirring, and the temperature was raised to 250 ° C. while discharging the generated condensed water out of the system. After the dropwise addition, the temperature was raised to 270 ° C. and continued for 20 minutes. Thereafter, 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 to 0.2 MPa with nitrogen gas, and the polymer was taken out as strands from a nozzle at the bottom of the polymerization vessel. After cooling with water, the polymer was pelletized with a pelletizer to obtain a polyamide resin.
No trimesic acid was detected in the unreacted monomers, confirming that trimesic acid was incorporated into the polyamide resin.
The obtained polyamide resin was evaluated in the same manner as in Comparative Example 1.

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

Reference Example 2
Polyamide MXD6 (Mitsubishi Gas Chemical Company, S6001) synthesized from metaxylylenediamine and adipic acid and trimesic acid were weighed out (each component is in parts by mass) as shown in Table 3, blended in a tumbler, and fed into a twin-screw extruder (Shibaura Machine Company, TEM26SS) from the base, melt-kneaded, and pellets of the resin composition were prepared. The temperature of the twin-screw extruder was set to 280°C.
The melting point, glass transition temperature and melt viscosity of the resin composition were measured in the same manner as in Comparative Example 1.

Reference Example 3
Polyamide MXD6 (Mitsubishi Gas Chemical Company, S6001) synthesized from metaxylylenediamine and adipic acid and trimesic acid were weighed out (each component is in parts by mass) as shown in Table 3, blended in a tumbler, and fed into a twin-screw extruder (Shibaura Machine Company, TEM26SS) from the base, melt-kneaded, and pellets of the resin composition were prepared. The temperature of the twin-screw extruder was set to 280°C.
The melting point, glass transition temperature and melt viscosity of the resin composition were measured in the same manner as in Comparative Example 1.

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 and melt tension were both low.
Furthermore, when trimesic acid was blended with the polyamide resin and the resulting mixture was melt-kneaded (Reference Examples 2 and 3), the blended polyamide resin had a lower melt viscosity.

Claims (14)

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. The polyamide resin according to claim 1, in which 50 mol% or more of the dicarboxylic acid is an α,ω-linear aliphatic dicarboxylic acid and/or an aromatic dicarboxylic acid having 4 to 20 carbon atoms. 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. The polyamide resin according to claim 1, in which 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. The polyamide resin according to claim 1, in which 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. The polyamide resin according to any one of claims 1 to 5, wherein 5 to 100 mol% of the dicarboxylic acid is one or more of adipic acid, sebacic acid, and dodecanedioic acid. The polyamide resin according to any one of claims 1 to 6, wherein the polyamide resin has a melt viscosity of 510 Pa·s or more, measured at a melting temperature of 250°C and a shear rate of 121.6 ^s-1. A resin composition comprising the polyamide resin according to any one of claims 1 to 7. A molded article formed from a resin composition containing the polyamide resin according to any one of claims 1 to 7. The molded article according to claim 9, which is an extrusion molded article. The molded article according to claim 9 or 10, which is a film, fiber or foam. 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. A method for producing a polyamide resin, wherein the polyamide resin is the polyamide resin described in any one of claims 1 to 7. A method for producing a molded body, comprising extrusion molding the resin composition according to claim 8.