Resin composition, molded article, and multilayer

Abstract

To provide a resin composition having excellent transparency while maintaining excellent barrier properties and to provide a molded body and a multilayer body.SOLUTION: There is provided a resin composition which comprises 50 to 99 pts.mass of a polyethylene terephthalate resin and 50 to 1 pts.mass of a polyamide resin, wherein the polyamide resin is a copolymer containing a structural unit derived from a diamine and a structural unit derived from a dicarboxylic acid, in which 70 mol% or more of a structural unit derived from a diamine is derived from a xylylenediamine, 65.0 to 95.0 mol% of a structural unit derived from a dicarboxylic acid is derived from an α,ω-linear aliphatic dicarboxylic acid having 4 to 8 carbon atoms, 35.0 to 5.0 mol% is derived from an α,ω-linear aliphatic dicarboxylic acid having 9 to 12 carbon atoms and the polyamide resin has a relative viscosity of 1.7 to 2.5.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to resin compositions, molded articles, and multilayer articles. [Background technology]

[0002] Polyester resins, such as polyethylene terephthalate (PET), possess excellent appearance characteristics including transparency and gloss, as well as superior mechanical properties, aroma retention, gas barrier properties, and recyclability. Therefore, polyester resins are widely used in various packaging materials such as films, sheets, and hollow containers. While polyester resins have high gas barrier properties, they are not always sufficient for applications requiring even greater gas barrier properties against oxygen and other elements. Methods to improve the gas barrier properties of polyester resins include vapor-depositing aluminum oxide or silicon oxide onto molded articles or packaging containers made of polyester resin, or coating, laminating, or melt-mixing resins with higher gas barrier properties than polyester resin onto molded articles or packaging containers made of polyester resin.

[0003] Here, ethylene-vinyl alcohol copolymer resin can be cited as one of the resins that has higher gas barrier properties than polyester resin. However, due to the characteristics of its molecular structure, ethylene-vinyl alcohol copolymer resin has poor compatibility with polyester resin, and the resin composition obtained by mixing the two resins becomes cloudy, which has the drawback of impairing the transparency that is a characteristic of polyester resin. Furthermore, at the optimal processing temperature for polyester resin, ethylene-vinyl alcohol copolymer resin tends to degrade rapidly due to heat, which has problems such as impairing the processing stability of polyester resin.

[0004] On the other hand, examples of gas barrier resins other than ethylene-vinyl alcohol copolymers include polyamide resins such as nylon 6 and nylon 66. In particular, polymeta-xylylene adipamide, obtained by polymerizing a diamine component mainly composed of meta-xylylenediamine and a dicarboxylic acid component mainly composed of adipic acid, is a polyamide resin with excellent gas barrier properties and is therefore preferred. Polymeta-xylylene adipamide has higher gas barrier properties compared to other polyamide resins, and its glass transition temperature, melting point, and crystallinity are similar to those of polyethylene terephthalate, which is particularly widely used among polyester resins. Therefore, its molding conditions are similar to those of polyester resins, and it is easy to mold and process them together with polyester resins. For this reason, polymeta-xylylene adipamide is a very suitable resin as a material for improving the gas barrier properties of polyester resins. Such resin compositions blended with polyester resins and polyamide resins are described in Patent Documents 1 and 2. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] International Publication No. 2020 / 250794 [Patent Document 2] International Publication No. 2017 / 094542 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] In the present inventors' investigations, it was found that a resin composition containing polymetaxylylene adipamide in a polyester resin exhibits excellent gas barrier properties, but in terms of transparency, even higher performance may be required depending on the application. The present invention aims to solve these problems and to provide a resin composition, molded articles, and multilayer articles that maintain excellent barrier properties while exhibiting excellent transparency. [Means for solving the problem]

[0007] Based on the above problems, the inventors conducted research and found that the above problems can be solved by adjusting the composition and relative viscosity of the polyamide resin. Specifically, the above problem was solved by the following means. <1> A resin composition comprising 50 to 99 parts by mass of polyethylene terephthalate resin and 50 to 1 part by mass of polyamide resin, wherein the polyamide resin comprises structural units derived from diamine and structural units derived from dicarboxylic acid, wherein 70 mol% or more of the structural units derived from diamine are derived from xylylenediamine, 65.0 to 95.0 mol% of the structural units derived from dicarboxylic acid are derived from α,ω-linear aliphatic dicarboxylic acid having 4 to 8 carbon atoms, and 35.0 to 5.0 mol% are copolymers derived from α,ω-linear aliphatic dicarboxylic acid having 9 to 12 carbon atoms, and the relative viscosity of the polyamide resin is 1.7 to 2.5. <2> Of the constituent units derived from the dicarboxylic acid, 71.0 to 95.0 mol% are derived from α,ω-linear aliphatic dicarboxylic acids having 4 to 8 carbon atoms, and 29.0 to 5.0 mol% are derived from α,ω-linear aliphatic dicarboxylic acids having 9 to 12 carbon atoms. <1> The resin composition described above. <3> Of the constituent units derived from the dicarboxylic acid, 75.0 to 95.0 mol% are derived from α,ω-linear aliphatic dicarboxylic acids having 4 to 8 carbon atoms, and 25.0 to 5.0 mol% are derived from α,ω-linear aliphatic dicarboxylic acids having 9 to 12 carbon atoms. <1> The resin composition described above. <4> The α,ω-linear aliphatic dicarboxylic acid having 4 to 8 carbon atoms includes adipic acid, and the α,ω-linear aliphatic dicarboxylic acid having 9 to 12 carbon atoms includes sebacic acid. <1> ~ <3> A resin composition as described in any one of the following. <5> 70 mol% or more of the constituent units derived from the diamine are derived from metaxylylenediamine. <1> ~ <4> A resin composition as described in any one of the following. <6> The relative viscosity of the polyamide resin is 1.9 to 2.2. <1> ~ <5> A resin composition as described in any one of the following. <7> <1> ~ <6> A molded article formed from any one of the resin compositions described above. <8> It is an extruded product. <7> The molded body described above. <9> It is film. <7> or <8> The molded body described above. <10> It is uniaxially or biaxially stretched. <9> The molded body described above. <11> It is an injection-molded product. <7> The molded body described above. <12> It is a hollow molded body. <7> or <11> The molded body described above. <13> <7> ~ <12> A multilayer body having a molded body as described in any one of the following. [Effects of the Invention]

[0008] The present invention makes it possible to provide a resin composition, molded articles, and multilayers that maintain excellent barrier properties while exhibiting excellent transparency. [Modes for carrying out the invention]

[0009] The following describes in detail embodiments for carrying out the present invention (hereinafter simply referred to as "this embodiment"). Note that the following embodiment is illustrative for explaining the present invention, and the present invention is not limited to this embodiment. In this specification, "~" is used to mean that the numbers before and after it are included as the lower and upper limits, respectively. In this specification, all physical properties and characteristic values ​​shall be those at 23°C unless otherwise specified. In this specification, the melting point (Tm) shall be the value measured according to differential scanning calorimetry (DSC) in accordance with ISO 11357. Specifically, it may be measured according to paragraph 0036 of International Publication No. 2016 / 084475, which is incorporated herein by reference. In this specification, multilayer materials include those in the form of films or sheets. "Film" and "sheet" refer to molded articles that are thin in thickness relative to their length and width, and are generally flat. Furthermore, "film" and "sheet" in this specification may be single-layer or multi-layer. When the measurement methods and the like described according to the standards shown in this specification differ from year to year, unless otherwise specified, they shall be based on the standards as of January 1, 2022.

[0010] The resin composition of the present embodiment contains 50 to 99 parts by mass of a polyethylene terephthalate resin and 50 to 1 part by mass of a polyamide resin. The polyamide resin contains a structural unit derived from a diamine and a structural unit derived from a dicarboxylic acid. 70 mol% or more of the structural unit derived from the diamine is derived from xylylenediamine, and 65.0 to 95.0 mol% of the structural unit derived from the dicarboxylic acid is derived from an α,ω-linear aliphatic dicarboxylic acid having 4 to 8 carbon atoms, and 35.0 to 5.0 mol% thereof is derived from an α,ω-linear aliphatic dicarboxylic acid having 9 to 12 carbon atoms. It is a copolymer, and the relative viscosity of the polyamide resin is 1.7 to 2.5. By adopting such a configuration, a resin composition excellent in transparency can be obtained while maintaining excellent barrier properties. By using an α,ω-linear aliphatic dicarboxylic acid having 9 to 12 carbon atoms together with an α,ω-linear aliphatic dicarboxylic acid having 4 to 8 carbon atoms as the dicarboxylic acid component constituting the polyamide resin, the crystallization rate becomes slow, and it becomes difficult to become turbid during solidification, and the transparency of the obtained molded body tends to improve. In particular, although a blend of a polyester resin and a polyamide resin tends to be inferior in transparency, in the present embodiment, it is highly significant that the transparency can be reduced by using a specific xylylenediamine-based polyamide resin. In particular, it is surprising that the haze is significantly reduced and the transparency is improved as compared with a polyester resin and MXD6 (a polyamide resin synthesized from metaxylylenediamine and adipic acid). In addition, by using a specific xylylenediamine-based polyamide resin, the oxygen barrier property is also improved. In addition, by setting the relative viscosity in the range of 1.7 to 2.5, the transparency tends to be further improved. This reason is presumably due to the improved dispersibility of the xylylenediamine-based polyamide resin.

[0011] <Polyethylene terephthalate resin> The resin composition of this embodiment contains polyethylene terephthalate resin. By containing polyethylene terephthalate resin, excellent mechanical properties, chemical resistance, and fragrance retention properties are achieved.

[0012] As the polyester resin used in this embodiment, preferably, it contains a structural unit derived from a diol and a structural unit derived from a dicarboxylic acid, and 70 mol% or more of the structural unit derived from the diol is derived from ethylene glycol, and 60 mol% or more of the structural unit derived from the dicarboxylic acid is derived from at least one selected from terephthalic acid and its esters (preferably terephthalic acid). Preferably, 85 mol% or more, more preferably 90 mol% or more, still more preferably 95 mol% or more, and even more preferably 99 mol% or more of the structural unit derived from the diol is derived from ethylene glycol. Also, preferably, 70 mol% or more, more preferably 80 mol% or more, still more preferably 90 mol% or more of the structural unit derived from the dicarboxylic acid is derived from at least one selected from terephthalic acid and its esters. The upper limit may be 100 mol%, and preferably 99 mol% or less.

[0013] Furthermore, in this embodiment, 60 to 99 mol% of the structural unit derived from the dicarboxylic acid may be derived from at least one selected from terephthalic acid and its esters (preferably terephthalic acid), and 40 to 1 mol% may be derived from at least one selected from isophthalic acid and its esters (preferably isophthalic acid). Also, in this embodiment, the proportion of the structural unit derived from at least one selected from isophthalic acid and its esters in the structural unit derived from the dicarboxylic acid is preferably 20 mol% or less, more preferably 15 mol% or less, still more preferably 10 mol% or less, and even more preferably 5 mol% or less.

[0014] The polyester resin used in this embodiment may further contain other constituent units, such as those derived from 1,4-cyclohexanedimethanol, in addition to the constituent units derived from the diol. However, in this embodiment, it is preferable that ethylene glycol is preferably 85 mol% or more, more preferably 90 mol% or more, even more preferably 95 mol% or more, and even more preferably 99 mol% or more of the constituent units derived from the diol. Furthermore, the polyester resin used in this embodiment may also contain other structural units, such as structural units derived from naphthalenedicarboxylic acid, in addition to structural units derived from dicarboxylic acid. However, in this embodiment, it is preferable that 85 mol% or more, more preferably 90 mol% or more, even more preferably 95 mol% or more, and even more preferably 99 mol% or more of the structural units derived from dicarboxylic acid are terephthalic acid and isophthalic acid and their esters (preferably terephthalic acid and isophthalic acid).

[0015] In this embodiment, the polyester resin is composed of diol-derived and dicarboxylic acid-derived constituent units, preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, even more preferably 98% by mass or more, and even more preferably 99% by mass or more of all constituent units excluding terminal groups.

[0016] The polyester resin contained in the polyester resin layer may be a crystalline polyester resin having a clear melting point, or an amorphous polyester resin not having a clear melting point, but it is preferable that it be a crystalline polyester resin having a melting point. In this embodiment, the melting point of the polyester resin is preferably 150°C or higher, more preferably 200°C or higher, even more preferably 220°C or higher, preferably 300°C or lower, more preferably 290°C or lower, and even more preferably 280°C or lower. In this embodiment, if the polyester resin layer contains two or more types of polyester resins, the melting point of the polyester resins shall be the value obtained by multiplying the melting point of each polyester resin by its mass fraction.

[0017] The intrinsic viscosity of the polyester resin is preferably 0.30 dL / g or higher, more preferably 0.40 dL / g or higher, and even more preferably 0.60 dL / g or higher. Furthermore, the intrinsic viscosity is preferably 2.00 dL / g or lower, more preferably 1.50 dL / g or lower, even more preferably 1.00 dL / g or lower, and even more preferably 0.90 dL / g or lower. In this embodiment, if the polyester resin layer contains two or more types of polyester resins, the intrinsic viscosity shall be the intrinsic viscosity of the polyester resin mixture.

[0018] Intrinsic viscosity is measured according to the following method. Dissolve the polyester resin (pellets) in a mixed solvent of phenol / 1,1,2,2-tetrachloroethane (mass ratio 1 / 1) by stirring at 110°C for 1 hour to a concentration of 1.00 g / dL. Then, cool to 30°C. Using a fully automated solution viscometer, measure the time it takes for the sample solution to fall and the time it takes for the solvent alone to fall at 30°C, and calculate the intrinsic viscosity using the following formula (1). Intrinsic viscosity=((1+4K H η sp ) 0.5 -1) / (2K H C) …(1) Here, η sp =η / η0-1, where η is the number of seconds for the sample solution to fall, η0 is the number of seconds for the solvent only to fall, C is the concentration of the sample solution (g / dL), and K is the concentration of the sample solution (g / dL). H K is Huggins' constant. H We will use 0.33.

[0019] In addition to the above, the polyester resins described in paragraphs 0064 to 0080 of Japanese Patent Publication No. 2016-169027, the polyester resins described in paragraphs 0010 to 0021 of Japanese Patent Publication No. 2006-111718, the polyester resins described in Japanese Patent Publication No. 2017-105873, and the polyester resins described in International Publication No. 2013 / 168804 may also be considered as polyester resins, and the contents of these are incorporated herein by reference.

[0020] The mass percentage of polyethylene terephthalate resin in the resin composition of this embodiment is preferably 50% by mass or more, more preferably more than 50% by mass, even more preferably 60% by mass or more, even more preferably 65% ​​by mass or more, even more preferably 75% by mass or more, and even more preferably 85% by mass or more. By setting it above the lower limit, high transparency can be maintained. Furthermore, the mass percentage of polyethylene terephthalate resin in the resin composition is preferably 99% by mass or less, more preferably 98% by mass or less, even more preferably 97% by mass or less, and even more preferably 96% by mass or less. By setting it below the upper limit, high gas barrier properties can be obtained. The resin composition of this embodiment may contain only one type of polyethylene terephthalate resin, or it may contain two or more types. When two or more types are included, it is preferable that the total amount is within the above range.

[0021] <Polyamide resin> The resin composition of this embodiment includes a polyamide resin. The polyamide resin used in this embodiment includes constituent units derived from diamine and constituent units derived from dicarboxylic acid, wherein 70 mol% or more of the constituent units derived from diamine are derived from xylylenediamine, 65.0 to 95.0 mol% of the constituent units derived from dicarboxylic acid are derived from α,ω-linear aliphatic dicarboxylic acid having 4 to 8 carbon atoms, and 35.0 to 5.0 mol% are derived from α,ω-linear aliphatic dicarboxylic acid having 9 to 12 carbon atoms, and the polyamide resin has a relative viscosity of 1.7 to 2.5. Hereinafter, in this specification, such a polyamide resin may be referred to as a "xylylenediamine-based polyamide resin". By using a xylylenediamine-based polyamide resin, a resin composition with excellent transparency and barrier properties can be obtained.

[0022] Xylylenediamine-based polyamide resins contain structural units derived from diamines and structural units derived from dicarboxylic acids, wherein 70 mol% or more of the structural units derived from diamines are derived from xylylenediamine, 65.0 to 95.0 mol% of the structural units derived from dicarboxylic acids are derived from α,ω-linear aliphatic dicarboxylic acids having 4 to 8 carbon atoms, and 35.0 to 5.0 mol% are derived from α,ω-linear aliphatic dicarboxylic acids having 9 to 12 carbon atoms.

[0023] In this embodiment, the xylylenediamine-based polyamide resin uses a copolymer in which the constituent units derived from dicarboxylic acids include both constituent units derived from α,ω-linear aliphatic dicarboxylic acids having 4 to 8 carbon atoms and constituent units derived from α,ω-linear aliphatic dicarboxylic acids having 9 to 12 carbon atoms. That is, it is a copolymer of at least xylylenediamine, α,ω-linear aliphatic dicarboxylic acids having 4 to 8 carbon atoms, and α,ω-linear aliphatic dicarboxylic acids having 9 to 12 carbon atoms. By using this copolymer, transparency is improved. In other words, when blending a polyamide resin (e.g., MXD6) in which 70 mol% or more of the diamine-derived structural units are derived from xylylenediamine and the dicarboxylic acid-derived structural units are derived from α,ω-linear aliphatic dicarboxylic acids having 4 to 8 carbon atoms, with a polyamide resin (e.g., MXD10) in which 70 mol% or more of the diamine-derived structural units are derived from xylylenediamine and the dicarboxylic acid-derived structural units are derived from α,ω-linear aliphatic dicarboxylic acids having 9 to 12 carbon atoms, sufficient transparency cannot be achieved. This is presumed to be because MXD6 and others are not sufficiently compatible with MXD10 and others. In this embodiment, this problem is solved by using a copolymer (MXD610, etc.). The xylylenediamine-based polyamide resin used in this embodiment is a copolymer of xylylenediamine (preferably metaxylylenediamine), a C4-C8 α,ω-linear aliphatic dicarboxylic acid (preferably adipic acid), and a C9-C12 α,ω-linear aliphatic dicarboxylic acid (preferably sebacic acid). Of the total structural units excluding the terminal groups, preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, even more preferably 98% by mass or more, and even more preferably 99% by mass or more are composed of structural units derived from xylylenediamine, a C4-C8 α,ω-linear aliphatic dicarboxylic acid, and a C9-C12 α,ω-linear aliphatic dicarboxylic acid.

[0024] In xylylenediamine-based polyamide resins, 70 mol% or more of the constituent units derived from diamines, preferably 80 mol% or more, more preferably 90 mol% or more, even more preferably 95 mol% or more, and even more preferably 99 mol% or more, are derived from xylylenediamine (preferably metaxylylenediamine). The upper limit may be 100 mol%. The xylylenediamine is preferably metaxylylenediamine and paraxylylenediamine, with metaxylylenediamine being more preferred. In this embodiment, the molar ratio of metaxylylenediamine to paraxylylenediamine in xylylenediamine is preferably 10-100 / 90-0, more preferably 30-100 / 70-0, even more preferably 50-100 / 50-0, even more preferably 80-100 / 20-0, even more preferably 90-100 / 10-0, even more preferably 95-100 / 5-0, and particularly most preferably 98-100 / 2-0, when the total amount of metaxylylenediamine and paraxylylenediamine is 100 moles. By increasing the ratio of metaxylylenediamine, the melting point rise can be suppressed and the processing temperature can be lowered, thereby more effectively suppressing the occurrence of charring and gel derived from xylylenediamine-based polyamide resins.

[0025] Other diamines that can be used as raw material diamine components for the polyamide resin in 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, as well as 1,3-bis(aminomethyl)cyclamine. Examples include alicyclic diamines such as oxahexane, 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, as well as aromatic ring-containing diamines such as bis(4-aminophenyl) ether, paraphenylenediamine, and bis(aminomethyl)naphthalene. These can be used individually or in combination of two or more.

[0026] In this embodiment, the dicarboxylic acid-derived constituent units of the xylylenediamine-based polyamide resin consist of 65.0 to 95.0 mol% derived from α,ω-linear aliphatic dicarboxylic acids having 4 to 8 carbon atoms, and 35.0 to 5.0 mol% derived from α,ω-linear aliphatic dicarboxylic acids having 9 to 12 carbon atoms. By using α,ω-linear aliphatic dicarboxylic acids having 4 to 8 carbon atoms, the amide bond density can be increased, and a polyamide resin with excellent oxygen barrier properties tends to be obtained. Furthermore, by using α,ω-linear aliphatic dicarboxylic acids having 9 to 12 carbon atoms, transparency tends to be improved compared to the case where only α,ω-linear aliphatic dicarboxylic acids having 4 to 8 carbon atoms are used as the dicarboxylic acid component.

[0027] More specifically, the proportion of α,ω-linear aliphatic dicarboxylic acid (preferably adipic acid) having 4 to 8 carbon atoms in the constituent units derived from the dicarboxylic acid is 65.0 mol% or more, preferably 71.0 mol% or more, more preferably 75.0 mol% or more, and even more preferably 78.0 mol% or more. Furthermore, the proportion of α,ω-linear aliphatic dicarboxylic acid (preferably adipic acid) having 4 to 8 carbon atoms in the constituent units derived from the dicarboxylic acid is 95.0 mol% or less, preferably 90.0 mol% or less, more preferably 88.0 mol% or less, and even more preferably 85.0 mol% or less. Furthermore, the proportion of α,ω-linear aliphatic dicarboxylic acid (preferably sebacic acid) having 9 to 12 carbon atoms in the constituent units derived from the dicarboxylic acid is 5.0 mol% or more, preferably 10.0 mol% or more, more preferably 12.0 mol% or more, and even more preferably 15.0 mol% or more. Furthermore, the proportion of α,ω-linear aliphatic dicarboxylic acid (preferably sebacic acid) having 9 to 12 carbon atoms in the constituent units derived from the dicarboxylic acid is 35.0 mol% or less, preferably 29.0 mol% or less, more preferably 25.0 mol% or less, and even more preferably 22.0 mol% or less.

[0028] In this embodiment, the constituent units derived from dicarboxylic acids in the xylylenediamine-based polyamide resin consist of 70 mol% or more, preferably 75 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 99.9 mol% or more, all of which are constituent units derived from α,ω-linear aliphatic dicarboxylic acids having 4 to 8 carbon atoms and constituent units derived from α,ω-linear aliphatic dicarboxylic acids having 9 to 12 carbon atoms. The upper limit of the total may be 100 mol%.

[0029] Examples of α,ω-linear aliphatic dicarboxylic acids having 4 to 8 carbon atoms include succinic acid, glutaric acid, pimelic acid, adipic acid, and suberic acid, with adipic acid being preferred. Examples of α,ω-linear aliphatic dicarboxylic acids having 9 to 12 carbon atoms include azelaic acid, sebacic acid, undecanediic acid, and dodecanediic acid, with sebacic acid being preferred. Sebacic acid can be derived from plant materials, which can increase the bio-based nature of the resin.

[0030] In this embodiment, it is preferable that the α,ω-linear aliphatic dicarboxylic acid having 4 to 8 carbon atoms contains adipic acid, and the α,ω-linear aliphatic dicarboxylic acid having 9 to 12 carbon atoms contains sebacic acid. Furthermore, it is preferable that the α,ω-linear aliphatic dicarboxylic acid having 4 to 8 carbon atoms contains adipic acid, preferably 90 mol% or more, more preferably 95 mol% or more, and even more preferably 99% or more, of which the α,ω-linear aliphatic dicarboxylic acid having 9 to 12 carbon atoms contains sebacic acid.

[0031] In xylylenediamine-based polyamide resins, one or more constituent units derived from α,ω-linear aliphatic dicarboxylic acids having 4 to 8 carbon atoms and two or more constituent units derived from α,ω-linear aliphatic dicarboxylic acids having 9 to 12 carbon atoms may be used. When two or more types are included, it is preferable that the total amount is within the above range.

[0032] Examples of dicarboxylic acid components other than the above-mentioned α,ω-linear aliphatic dicarboxylic acids having 4 to 12 carbon atoms include phthalate compounds such as isophthalic acid, terephthalic acid, and orthophthalic acid, and naphthalenedicarboxylic acids 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, which can be used individually or in mixtures of two or more.

[0033] A particularly preferred form of the xylylenediamine-based polyamide resin in this embodiment is a polyamide resin containing constituent units derived from diamine and constituent units derived from dicarboxylic acid, wherein 95 mol% or more (more preferably 98 mol% or more, and even more preferably 99.9 mol% or more) of the constituent units derived from diamine are derived from metaxylylenediamine, 75.0 to 95.0 mol% of the constituent units derived from dicarboxylic acid are derived from adipic acid, and 25.0 to 5.0 mol% are derived from sebacic acid, and the sum of the constituent units derived from adipic acid and sebacic acid accounts for 95 mol% or more (more preferably 98 mol% or more, and even more preferably 99.9 mol% or more) of the constituent units derived from dicarboxylic acid.

[0034] The xylylenediamine-based polyamide resin used in this embodiment contains structural units derived from dicarboxylic acids and diamines, but may also contain structural units other than those derived from dicarboxylic acids and diamines, as well as other parts such as terminal groups. Examples of other structural units include, but are not limited to, those derived from lactams such as ε-caprolactam, valerolactam, laurolactam, and undecalactam, and aminocarboxylic acids such as 11-aminoundecanoic acid and 12-aminododecanoic acid. Furthermore, the xylylenediamine-based polyamide resin used in this embodiment may also contain trace components such as additives used in the synthesis. In this embodiment, the xylylenediamine-based polyamide resin consists of, preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, even more preferably 98% by mass or more, and even more preferably 99% by mass or more of all constituent units excluding terminal groups, which are constituent units derived from dicarboxylic acids and constituent units derived from diamines. The upper limit may be 100% by mass.

[0035] The relative viscosity of the xylylenediamine-based polyamide resin used in this embodiment is 1.7 or higher, preferably 1.9 or higher, and more preferably 2.0 or higher. Furthermore, the relative viscosity of the xylylenediamine-based polyamide resin is 2.5 or lower, preferably 2.4 or lower, more preferably 2.3 or lower, and may also be 2.2 or lower. The relative viscosity of the xylylenediamine-based polyamide resin used in this embodiment is the ratio of the falling time (t) of 0.2 g of the xylylenediamine-based polyamide resin dissolved in 20 mL of 96% sulfuric acid, measured at 25°C using a Cannon-Fenske viscometer, to the falling time (t0) of the 96% sulfuric acid itself, measured in the same manner, and is expressed by the following formula. Relative viscosity=t / t0 In this embodiment, if the polyamide resin layer contains two or more xylylenediamine-based polyamide resins, the relative viscosity of the mixture is used.

[0036] The melting point of the xylylenediamine-based polyamide resin used in this embodiment, as measured by differential scanning calorimetry, is preferably 195°C or higher, more preferably 200°C or higher, even more preferably 205°C or higher, and even more preferably 210°C or higher. The melting point of the xylylenediamine-based polyamide resin is preferably 235°C or lower, more preferably 230°C or lower, even more preferably 225°C or lower, and even more preferably 220°C or lower. In this embodiment, if the resin composition contains two or more xylylenediamine-based polyamide resins, the melting point of the xylylenediamine-based polyamide resin is the value obtained by multiplying the melting point of each xylylenediamine-based polyamide resin by its mass fraction.

[0037] The mass percentage of xylylenediamine-based polyamide resin in the resin composition of this embodiment is preferably 1% by mass or more, more preferably 2% by mass or more, even more preferably 3% by mass or more, and even more preferably 4% by mass or more. Setting it above the lower limit makes it possible to obtain higher gas barrier properties. Furthermore, the mass percentage of xylylenediamine-based polyamide resin in the resin composition is preferably 50% by mass or less, more preferably less than 50% by mass, even more preferably 40% by mass or less, even more preferably 35% by mass or less, even more preferably 25% by mass or less, and even more preferably 15% by mass or less. Setting it below the upper limit makes it possible to maintain high transparency. The resin composition of this embodiment may contain only one type of xylylenediamine-based polyamide resin, or it may contain two or more types. When two or more types are included, it is preferable that the total amount is within the above range.

[0038] <Blending ratio of polyethylene terephthalate resin and xylylenediamine-based polyamide resin> Next, the blend ratio of polyethylene terephthalate resin and xylylenediamine-based polyamide resin in the resin composition of this embodiment will be described. In this embodiment, the polyethylene terephthalate resin is included in a ratio of 50 to 1 part by mass of xylylenediamine-based polyamide resin to 50 to 99 parts by mass of polyethylene terephthalate resin. Furthermore, when the total of polyethylene terephthalate resin and xylylenediamine-based polyamide resin is 100 parts by mass, the mass percentage of xylylenediamine-based polyamide resin is preferably 1 part by mass or more, more preferably 2 parts by mass or more, even more preferably 3 parts by mass or more, and even more preferably 4 parts by mass or more. Furthermore, the mass percentage of xylylenediamine-based polyamide resin in the resin composition is preferably 50 parts by mass or less, more preferably less than 50 parts by mass, even more preferably 40 parts by mass or less, even more preferably 35 parts by mass or less, even more preferably 25 parts by mass or less, even more preferably 20 parts by mass or less, and even more preferably 15 parts by mass or less. The total amount of polyethylene terephthalate resin and xylylenediamine-based polyamide resin in the resin composition of this embodiment is preferably 70% by mass or more, more preferably 75% by mass or more, even more preferably 80% by mass or more, even more preferably 85% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, and may also be 97% by mass or more. Furthermore, the upper limit of the total amount of polyethylene terephthalate resin and xylylenediamine-based polyamide resin in the resin composition of this embodiment may be 100% by mass.

[0039] <Other ingredients> The resin composition of this embodiment may also contain polyamide resins other than xylylenediamine-based polyamide resins, thermoplastic resins other than polyamide resins and polyethylene terephthalate resins, fillers, and resin additive components.

[0040] Other than xylylenediamine-based polyamide resins, the polyamide resin may be an aliphatic polyamide resin, a semi-aromatic polyamide resin, or a mixture of an aliphatic polyamide resin and a semi-aromatic polyamide resin, but it is preferable that it contains at least a semi-aromatic polyamide resin. For example, as a polyamide resin, reference can be given to paragraphs 0011 to 0013 of Japanese Patent Application Publication No. 2011-132550, which is incorporated herein by reference. Examples of aliphatic polyamide resins include polyamide 6 and polyamide 66, with polyamide 66 being preferred. Examples of semi-aromatic polyamide resins include terephthalic acid-based polyamide resins (polyamide 6T, polyamide 9T, polyamide 10T) and terephthalic acid and isophthalic acid-based polyamide resins (polyamide 6T / 6I, polyamide 9T / 9I, polyamide 10T / 10I). The resin composition may contain only one polyamide resin other than the xylylenediamine-based polyamide resin, or it may contain two or more polyamide resins other than the xylylenediamine-based polyamide resin. Preferably, the polyamide resin other than the xylylenediamine-based polyamide resin is blended in a ratio of 10 parts by mass or less per 100 parts by mass of the xylylenediamine-based polyamide resin.

[0041] Regarding fillers, the description in paragraphs 0029 to 0035 of Japanese Patent Publication No. 2020-200380 can be referenced, and this content will be incorporated into the specification. Furthermore, when a filler is included, its content is preferably 10 to 50% by mass of the resin composition.

[0042] Examples of resin additives include oxidation accelerators, yellowing inhibitors, oxygen absorbers, heat stabilizers, light stabilizers, moisture-proofing agents, waterproofing agents, lubricants (such as calcium stearate), and spreading agents. Regarding oxidation accelerators and yellowing inhibitors, reference can be made to paragraphs 0061-0070 of International Publication No. 2021 / 177126, and these contents are incorporated herein by reference.

[0043] <Method for producing resin compositions> The resin composition of this embodiment can be manufactured by a known method for manufacturing thermoplastic resin compositions. As one embodiment of the method for producing the resin composition of this embodiment, it is preferable to melt-knead polyethylene terephthalate resin, polyamide resin, and other components as needed. An example of such a resin composition is pellets. Specifically, one method involves pre-mixing each component using various mixers such as tumblers and Henschel mixers, and then melt-kneading them in mixers such as Banbury mixers, rolls, brabenders, single-screw extruders, twin-screw extruders, and kneaders. It is preferable to supply the reinforcing filler partway through the extruder to suppress crushing during kneading. Alternatively, two or more components selected from each component may be pre-mixed and kneaded.

[0044] <Physical properties of resin compositions> Next, the physical properties of the resin composition of this embodiment will be described. The resin composition of this embodiment exhibits excellent transparency. Specifically, the resin composition of this embodiment preferably has a haze of 35.0% or less, and more preferably 10.0% or less, when molded into an unoriented film with a thickness of 180 μm. Ideally, the lower limit should be 0%, but 0.1% or more is practical. The excellent transparency of such an unoriented film is achieved by using α,ω-linear aliphatic dicarboxylic acids with 9 to 12 carbon atoms, along with α,ω-linear aliphatic dicarboxylic acids with 4 to 8 carbon atoms, as the dicarboxylic acid component constituting the polyamide resin. Furthermore, the resin composition of this embodiment preferably has a haze of 35.0% or less when formed into a stretched film with a thickness of 20 μm, more preferably 25.0% or less, and even more preferably 20.0% or less. Ideally, the lower limit would be 0%, but 0.1% or more is practical. The excellent transparency of such a stretched film is achieved by adjusting the relative viscosity of the xylylenediamine-based polyamide resin. The resin composition of this embodiment exhibits excellent oxygen barrier properties. Specifically, the resin composition of the present embodiment preferably has an oxygen barrier property of 5.0 (cc·mm) / (m 2 ·day·atm) or less when formed into an unstretched film with a thickness of 180 μm. The lower limit of the oxygen barrier property is preferably 0 (cc·mm) / (m 2 ·day·atm), but it is practical to be 0.01 (cc·mm) / (m 2 ·day·atm) or more. Such excellent oxygen barrier property of the unstretched film is achieved by using a xylylenediamine-based polyamide resin, particularly a polyamide resin containing a structural unit derived from an α,ω-linear aliphatic dicarboxylic acid having 4 to 8 carbon atoms as a dicarboxylic acid unit. In addition, the resin composition of the present embodiment preferably has an oxygen barrier property of 2.0 (cc·mm) / (m 2 ·day·atm) or less when formed into a stretched film with a thickness of 20 μm, and more preferably 1.5 (cc·mm) / (m 2 ·day·atm) or less. The lower limit of the oxygen barrier property is preferably 0 (cc·mm) / (m 2 ·day·atm), but it is practical to be 0.01 (cc·mm) / (m 2 ·day·atm) or more. Such excellent oxygen barrier property of the stretched film is achieved by stretching. The stretched film is, for example, a stretched film manufactured under the conditions described in the examples.

[0045] <Use and Molding Method of Resin Composition> Next, the use of the resin composition of the present embodiment will be described. The molded body of the present embodiment is formed from the resin composition of the present embodiment. The manufacturing method of the molded body of the present embodiment is not particularly defined. For example, the molded body of the present embodiment may be directly molded by various molding methods after melt-kneading each component, or may be melt-kneaded and pelletized each component, and then melted again and molded by various molding methods.

[0046] The method for forming the molded article is not particularly limited, and conventionally known molding methods can be employed. Examples include injection molding, injection compression molding, extrusion molding, shape extrusion, transfer molding, hollow molding, gas-assisted hollow molding, blow molding, extrusion blow molding, IMC (in-mold coating) molding, rotational molding, multilayer molding, two-color molding, insert molding, sandwich molding, foam molding, and pressure molding.

[0047] One embodiment of the molded body according to this embodiment is an extruded molded body. Another embodiment of the molded body according to this embodiment is an injection molded body. The shape of the molded body in this embodiment is not particularly limited and can be appropriately selected according to the application and purpose of the molded body. Examples include sheet-like, film-like, cylindrical, annular, circular, elliptical, plate-like, rod-like, gear-like, polygonal, hollow, frame-like, box-like, and panel-like shapes, with hollow shapes being preferred.

[0048] The molded article of this embodiment is preferably a film. The film is preferably a stretched film. The stretched film may be a single-layer stretched film or a multi-layer stretched film. The film is usually an extruded product formed by extrusion molding. The stretched film is preferably stretched after being extruded by extrusion molding while being conveyed between rolls. Stretching may be performed in one direction only (uniaxial stretching) or in two orthogonal directions (biaxial stretching), with biaxial stretching being preferred. Stretching is preferably performed in one of the following directions: the machine direction (sometimes referred to as "MD") or the transverse direction (sometimes referred to as "TD") of the film (more preferably MD), or in both MD and TD directions. In the case of biaxial stretching, the two stretching directions may be performed simultaneously or sequentially. When stretching a film uniaxially, the stretching ratio (MD or TD stretching ratio) is preferably 2 times or more, more preferably 3 times or more, and even more preferably 5 times or more. When a film is biaxially stretched, the stretching ratio is preferably 2 times or more in each direction, more preferably 2.5 times or more, and even more preferably 2.9 times or more. There is no particular upper limit for each stretching ratio when uniaxial or biaxial stretching is performed, but they can be, for example, 5 times or less, more preferably 4 times or less, and especially 3.5 times or less. The total stretching ratio of the film is preferably 4 times or more, more preferably 6 times or more, and even more preferably 8 times or more. There is no upper limit set for the total stretching ratio, but for example it can be 25 times or less, more preferably 16 times or less, and especially preferably 13 times or less. Here, the total stretching ratio is the ratio of the area of ​​the film after stretching to the area of ​​the film before stretching, and is expressed by the following formula. Total extension ratio = MD extension ratio x TD extension ratio

[0049] The molded article of this embodiment may also preferably be a multilayer structure laminated with other layers. Examples of other layers included in the multilayer structure include polyolefin films (particularly stretched polyolefin films), polyester films (particularly polyethylene terephthalate films), and metal vapor-deposited films. Other examples of other layers included in the multilayer structure include barrier resin layers, oxygen absorption layers, sealant layers, and decorative layers.

[0050] Furthermore, the single-layer or multi-layer film of this embodiment may be subjected to heat treatment or humidity control treatment depending on the application. Details thereof can be found in paragraph 0049 of International Publication No. 2021 / 070500, which is incorporated herein by reference. Furthermore, with respect to the manufacture of stretched films and multilayer films, the descriptions in paragraphs 0025-0030 of International Publication No. 2019 / 208687 and the descriptions in Japanese Patent Application Publication No. 2001-002800 can be referenced without departing from the spirit of the present invention, and these contents are incorporated herein.

[0051] The molded article of this embodiment is preferably a hollow molded article. An example of a hollow molded article is a bottle. The hollow molded article is, for example, an injection-molded article formed by injection molding. Examples of hollow molded bodies include single-layer containers and multi-layer containers, with single-layer containers being preferred. In the case of multi-layer containers, examples include multi-layer containers having a layer formed from the resin composition of this embodiment and other resin layers. For example, a multi-layer container having a three-layer structure of polyethylene terephthalate resin layer / layer formed from the resin composition of this embodiment / polyethylene terephthalate resin layer is an example. The type of container is not particularly defined, and examples include bottles, cups, tubes, trays, Tupperware, etc., with bottles being preferred. Single-layer or multi-layer containers can be formed, for example, by injection molding to create a preform, followed by blow molding.

[0052] There is no specific field of application for the molded article of this embodiment. When the molded article of this embodiment is a single-layer or multi-layer film, or a single-layer or multi-layer container, it is preferably used as a packaging material. Examples of packaging materials of this embodiment include those for food, medical, and cosmetic use. The contents that can be filled or packaged in the packaging material of this embodiment include: confectionery such as rice crackers, bean snacks, nuts, biscuits, cookies, wafers, marshmallows, pies, semi-fresh cakes, candies, and snack foods; staples such as bread, instant noodles, dried noodles, pasta, aseptically packaged rice, rice porridge, congee, packaged mochi, and cereal foods; processed agricultural products such as pickles, boiled beans, natto, miso, freeze-dried tofu, tofu, enoki mushrooms, konjac, processed wild vegetables, jams, peanut butter, salads, frozen vegetables, and processed potato products; processed livestock products such as ham, bacon, sausages, processed chicken products, and corned beef; fish ham, fish sausage, Examples of prohibited items include processed seafood products such as fish paste products, kamaboko (fish cake), nori (seaweed), tsukudani (simmered seafood), katsuobushi (dried bonito flakes), shiokara (salted seafood), smoked salmon, and spicy mentaiko (pollock roe); fruits such as peaches, oranges, pineapples, mangoes, apples, pears, and cherries; vegetables such as corn, asparagus, mushrooms, onions, carrots, radishes, and potatoes; frozen and chilled prepared foods such as hamburgers, meatballs, fried seafood, gyoza (dumplings), and croquettes; dairy products such as butter, margarine, cheese, cream, instant creamy powder, and infant formula; liquid seasonings, retort curry, pet food, and other food products; cigarettes, disposable hand warmers, pharmaceuticals, and cosmetics. [Examples]

[0053] The present invention will be described in more detail below with reference to examples. The materials, amounts used, proportions, processing content, and processing procedures shown in the following examples can be modified as appropriate, as long as they do not depart 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 other reasons, measurements can be taken using other instruments with equivalent performance. Note that AA represents adipic acid, SA represents sebacic acid, and RV represents relative viscosity.

[0054] 1. Raw materials PET1: BK2180, manufactured by Mitsubishi Chemical Corporation, isophthalic acid copolymerized polyethylene terephthalate (intrinsic viscosity: 0.83 dL / g, melting point: 248 °C) PET2: RT-553C, manufactured by Mitsubishi Chemical Corporation, polyethylene terephthalate (intrinsic viscosity: 0.84 dL / g, melting point: 255 °C)

[0055] MXD610(AA:SA = 80:20): Synthesized according to the following synthesis example. <Synthesis example of MXD610> Into a reaction vessel equipped with a stirrer, a partial condenser, a total condenser, a thermometer, a dropping funnel, a nitrogen inlet tube, and a strand die, 10,000 g (68 mol) of adipic acid, 3,460 g (17.1 mol) of sebacic acid, 0.38 g of sodium hypophosphite monohydrate (NaH2PO2·H2O) (5 ppm in terms of the concentration of phosphorus atoms in the polyamide resin), and 0.15 g of sodium acetate were accurately weighed and blended. After sufficient nitrogen substitution, the system was filled with nitrogen to an internal pressure of 0.4 MPa, and then heated to 190 °C while stirring the system under a small amount of nitrogen flow. 11,813 g (87 mol) of metaxylylenediamine was dropped into this under stirring, and the internal temperature of the system was continuously increased while removing the generated condensation water out of the system. After the dropping of metaxylylenediamine was completed, the internal temperature was raised. When it reached 255 °C, the inside of the reaction vessel was depressurized, and the internal temperature was further raised to continue the melt polycondensation reaction at 260 °C for 10 minutes. Then, the system was pressurized with nitrogen, and the obtained polymer was taken out from the strand die and pelletized to obtain polyamide MXD610(80 / 20). The RV of the obtained resin was 2.1, and the melting point was 212 °C.

[0056] MXD610(AA:SA = 80:20): Synthesized according to the following synthesis example. <Synthesis example of MXD610> Into a reaction vessel equipped with a stirrer, a partial condenser, a total condenser, a thermometer, a dropping funnel, a nitrogen inlet tube, and a strand die, 10,000 g (68 mol) of adipic acid, 3,460 g (17.1 mol) of sebacic acid, 0.38 g of sodium hypophosphite monohydrate (NaH₂PO₂·H₂O) (equivalent to 5 ppm by mass of phosphorus atoms in the polyamide resin), and 0.15 g of sodium acetate were accurately weighed and blended. After sufficient nitrogen substitution, the vessel was filled with nitrogen up to an internal pressure of 0.4 MPa, and then heated to 190 °C while stirring the system under a slight nitrogen flow. 11,813 g (87 mol) of metaxylenediamine was added dropwise thereto while stirring, and the internal temperature of the system was continuously increased while removing the generated condensed water out of the system. After the completion of the dropwise addition of metaxylenediamine, the internal temperature was raised. When it reached 255 °C, the pressure inside the reaction vessel was reduced, and then the internal temperature was further raised to continue the melt polycondensation reaction at 260 °C for 10 minutes. Thereafter, the system was pressurized with nitrogen, and the obtained polymer was taken out from the strand die and pelletized to obtain polyamide MXD610(80 / 20). The obtained resin was dried in a batch dryer at 180 °C for 2 hours to increase the degree of polymerization, and a resin with RV2.7 and a melting point of 212 °C was obtained.

[0057] MXD610(AA:SA = 90:10) was synthesized according to the following synthesis example. <Synthesis Example of MXD610(90 / 10)> Into a reaction vessel equipped with a stirrer, a partial condenser, a total condenser, a thermometer, a dropping funnel, a nitrogen inlet tube, and a strand die, 10,000 g (68 mol) of adipic acid, 1,538 g (7.6 mol) of sebacic acid, 0.33 g of sodium hypophosphite monohydrate (NaH₂PO₂·H₂O) (equivalent to 5 ppm by mass of phosphorus atoms in the polyamide resin), and 0.13 g of sodium acetate were accurately weighed and blended. After sufficient nitrogen substitution, the vessel was filled with nitrogen up to an internal pressure of 0.4 MPa, and then heated to 190 °C while stirring the system under a slight nitrogen flow. 10,500 g (77 mol) of metaxylylenediamine was added dropwise thereto with stirring, and the temperature inside the system was continuously increased while removing the generated condensation water outside the system. After completion of the dropwise addition of metaxylylenediamine, the internal temperature was raised. When it reached 255 °C, the inside of the reaction vessel was depressurized, and the internal temperature was further raised to continue the melt polycondensation reaction at 260 °C for 10 minutes. Thereafter, the system was pressurized with nitrogen, and the obtained polymer was taken out from the strand die and pelletized to obtain polyamide MXD610(90 / 10). The RV of the obtained resin was 2.1, and the melting point was 225 °C.

[0058] MXD610(AA:SA = 70:30): It was synthesized according to the following synthesis example. <Synthesis Example of MXD610(70 / 30)> Into a reaction vessel equipped with a stirrer, a partial condenser, a total condenser, a thermometer, a dropping funnel, a nitrogen inlet tube, and a strand die, 10,000 g (68 mol) of adipic acid, 5,931 g (29.3 mol) of sebacic acid, 0.44 g of sodium hypophosphite monohydrate (NaH2PO2·H2O) (5 mass ppm in terms of the phosphorus atom concentration in the polyamide resin), and 0.17 g of sodium acetate were blended. After sufficient nitrogen substitution, nitrogen was filled to an internal pressure of 0.4 MPa, and the system was heated to 190 °C while stirring under a small amount of nitrogen stream. 13,500 g (99 mol) of metaxylylenediamine was added dropwise thereto with stirring, and the temperature inside the system was continuously increased while removing the generated condensation water outside the system. After completion of the dropwise addition of metaxylylenediamine, the internal temperature was raised. When it reached 255 °C, the inside of the reaction vessel was depressurized, and the internal temperature was further raised to continue the melt polycondensation reaction at 260 °C for 10 minutes. Thereafter, the system was pressurized with nitrogen, and the obtained polymer was taken out from the strand die and pelletized to obtain polyamide MXD610(70 / 30). The RV of the obtained resin was 2.1, and the melting point was 210 °C.

[0059] MXD10: It was synthesized according to the following synthesis example. <Synthesis Example of MXD10> Sebacic acid (manufactured by CASDA) was added to a jacketed reaction vessel equipped with a stirrer, condenser, cooler, thermometer, dropping tank, and nitrogen gas inlet tube. After thorough nitrogen purging, it was heated to 170°C and melted. While stirring the contents, metaxylylenediamine (manufactured by Mitsubishi Gas Chemical Co., Ltd., MXDA) was gradually added dropwise to maintain a molar ratio of 1:1 with sebacic acid, and the temperature was raised to 240°C. After the dropwise addition was complete, the temperature was raised to 260°C and continued for 20 minutes. Subsequently, the internal pressure of the reaction system was continuously reduced to 0.08 MPa, and the reaction was continued. After the reaction was complete, the reaction vessel was pressurized with nitrogen gas to 0.2 MPa, and the polymer was removed as strands from a nozzle at the bottom of the polymerization tank. After water cooling, it was pelletized in a pelletizer to obtain the polymer. The obtained resin had an RV of 2.1 and a melting point of 190°C.

[0060] MXD6: Manufactured by Mitsubishi Gas Chemical Company, Inc., Part Number: S6001, RV2.1, Melting Point 237℃

[0061] Examples 1-6, Comparative Examples 1-6 <Manufacturing of unoriented and oriented films> The polyester resin and polyamide resin shown in Table 1 or Table 2 were supplied in the proportions (unit: parts by mass) shown in Table 1 or Table 2 to a single-screw extruder with a T-die (manufactured by Plastics Engineering Research Institute, screw diameter 30 mm), melt-kneaded at 270°C, and extruded from the die to obtain an unstretched film with a thickness of 180 μm and a width of 130 mm. Furthermore, the obtained unstretched film was cut into 90 mm squares. Then, using a biaxial stretching machine (Tenter method, EX105S, manufactured by Toyo Seiki Seisakusho Co., Ltd.), the film was stretched in both the MD and TD directions to a stretching ratio of 3 x 3, obtaining a stretched film with a thickness of 20 μm. In this stretching process, relaxation operations were incorporated to achieve MD relaxation rates of 5.0% and TD relaxation rates of 5.0%. After stretching, heat fixing was performed. The heat fixing temperature was 170°C and the heat fixing time was 30 seconds to obtain a single-layer stretched film. The obtained unstretched and stretched films were evaluated for various properties as follows. The results are shown in Table 1 or Table 2 below.

[0062] <haze> The haze values ​​of the obtained unstretched and stretched films were measured using a haze meter. The haze meter used was the "COH-300A" manufactured by Nippon Denshoku Industries Co., Ltd.

[0063] <Oxygen barrier properties> The obtained unoriented and oriented films were subjected to an isobaric method to determine their oxygen permeability (OTR, unit: cc·mm / m²) under conditions of 23°C and 60% relative humidity (RH). 2 The pressure (atm / day) was measured. The oxygen atmosphere pressure was set to 1 atm, and the measurement time was 24 hours (1 day). Oxygen permeability (OTR) was measured using an oxygen permeability measuring device (MOCON Corporation, "OX-TRAN® 2 / 21").

[0064] [Table 1]

[0065] [Table 2]

[0066] In Tables 1 and 2 above, MXD610 (AA:SA=80:20) refers to MXD6, where the molar ratio of adipic acid to sebacic acid is 80:20. The same principle applies to other polyamide resins. As is clear from the results above, the resin composition of this embodiment exhibited excellent transparency and oxygen barrier properties. In particular, while blends of polyester resin and polyamide resin tend to have poor transparency, it is remarkable that the use of a specific xylylenediamine-based polyamide resin in this invention significantly reduced haze and improved transparency.< / haze>

Claims

1. It contains 50 to 99 parts by mass of polyethylene terephthalate resin and 50 to 1 part by mass of polyamide resin. The polyamide resin comprises a constituent unit derived from a diamine and a constituent unit derived from a dicarboxylic acid, wherein 70 mol% or more of the constituent units derived from the diamine are derived from xylylenediamine, 65.0 to 95.0 mol% of the constituent units derived from the dicarboxylic acid are derived from α,ω-linear aliphatic dicarboxylic acids having 4 to 8 carbon atoms, and 35.0 to 5.0 mol% are copolymers derived from α,ω-linear aliphatic dicarboxylic acids having 9 to 12 carbon atoms. The relative viscosity of the polyamide resin is 1.7 to 2.

5. Resin composition.

2. The resin composition according to claim 1, wherein 71.0 to 95.0 mol% of the constituent units derived from the dicarboxylic acid are derived from α,ω-linear aliphatic dicarboxylic acids having 4 to 8 carbon atoms, and 29.0 to 5.0 mol% are derived from α,ω-linear aliphatic dicarboxylic acids having 9 to 12 carbon atoms.

3. The resin composition according to claim 1, wherein 75.0 to 95.0 mol% of the constituent units derived from the dicarboxylic acid are derived from α,ω-linear aliphatic dicarboxylic acids having 4 to 8 carbon atoms, and 25.0 to 5.0 mol% are derived from α,ω-linear aliphatic dicarboxylic acids having 9 to 12 carbon atoms.

4. The resin composition according to any one of claims 1 to 3, wherein the α,ω-linear aliphatic dicarboxylic acid having 4 to 8 carbon atoms comprises adipic acid, and the α,ω-linear aliphatic dicarboxylic acid having 9 to 12 carbon atoms comprises sebadic acid.

5. The resin composition according to any one of claims 1 to 4, wherein 70 mol% or more of the constituent units derived from the diamine are derived from metaxylylenediamine.

6. The resin composition according to any one of claims 1 to 5, wherein the relative viscosity of the polyamide resin is 1.9 to 2.

2.

7. A molded article formed from the resin composition according to any one of claims 1 to 6.

8. The molded article according to claim 7, which is an extruded molded article.

9. A molded article according to claim 7 or 8, which is a film.

10. The molded article according to claim 9, which is uniaxially stretched or biaxially stretched.

11. The molded article according to claim 7, which is an injection-molded article.

12. The molded article according to claim 7 or 11, which is a hollow molded article.

13. A multilayer body having a molded article according to any one of claims 7 to 12.

Images