Polyester resin composition and polyester resin molded body

Abstract

Provided is a polyester resin composition containing an aromatic polyester resin. The heat resistance of a molded body obtained by molding the polyester resin composition is excellent, deformation of the molded body is suppressed, and the impact resistance of the molded body is excellent. Also provided is a polyester resin molded body that is obtained by molding such a polyester resin composition, and has excellent heat resistance, suppressed deformation, and excellent impact resistance.　A polyester resin composition according to an embodiment of the present invention contains an aromatic polyester resin (A), an organic crystallization accelerator (B), and a polycarbodiimide compound (C). The crystallinity of a polyester resin molded body, obtained by injection molding the polyester resin composition at a mold temperature of 30°C using a mold from which a molded article having a thickness of 2 mm is obtained, is 50% or more.

Description

Polyester resin composition and polyester resin molded article

[0001] The present invention relates to polyester resin compositions and polyester resin molded articles.

[0002] Thermoplastic polyester resins typically have a glass transition temperature (Tg) higher than room temperature, making crystallization at room temperature difficult, unlike thermoplastic polyolefin resins. Therefore, when heat resistance is required for thermoplastic polyester resins, some means are needed to promote crystallization.

[0003] One method to promote such crystallization is to perform an annealing treatment after molding a thermoplastic polyester resin. However, if crystallization is promoted by heating during the annealing treatment, problems arise such as resin sagging and shrinkage of the molded product due to crystallization, causing the molded product to deform.

[0004] A technique is known in which a polyester resin is vacuum-formed into a three-dimensional shape using a mold at a mold temperature of 50°C, and then fixed with a separate wooden mold of the same shape and subjected to annealing treatment to suppress deformation of the molded product due to annealing (Patent Document 1). However, this technique has the problem of being costly and time-consuming because a considerable number of fixing jigs are required.

[0005] As a polyester molding composition, a composition is known that includes a reaction product of at least one thermoplastic polyester-containing polymer and a copolymer of at least one copolymer of ethylene and glycidyl acrylate or glycidyl methacrylate, wherein the glycidyl acrylate or glycidyl methacrylate portion is present in the copolymer in an amount of about 2 to about 20% by weight, and which contains 0 to about 30% by weight of an unsaturated comonomer selected from the group consisting of C3 to C18α-olefins, styrenes, and acrylics having nitrile, ester, amide, or imide functional groups, and at least one nucleating agent which is a group I metal salt of a carboxylic acid-containing compound in an amount sufficient to increase the crystallization rate of the polyester (Patent Document 2). However, in this technology, the mold temperature during injection molding is high, at 85°C (Examples 1 to 11) and 119°C (Examples 13 to 17), which causes shrinkage of the molded body due to crystallization in the mold, making demolding difficult and resulting in the surface of the molded body being attached to the mold side. Furthermore, this technology essentially incorporates glass fibers as a reinforcing component, which leads to the problem of increased product weight. Additionally, the use of glass fibers accelerates screw wear during mixing and molding. Moreover, the use of glass fibers causes fiber orientation, which can lead to oriented molded products and potentially cause defects in properties depending on the shape.

[0006] A polyester resin composition is known that is obtained by melt-kneading polyethylene terephthalate and filler granules, wherein the filler granules contain a filler and a filler binder, the filler binder is a polyolefin resin, and the content of the filler in the polyester resin composition is 20% to 70% by weight (Patent Document 3). However, in this technology, the mold temperature during injection molding is high at 90°C, which causes shrinkage of the molded body due to crystallization inside the mold, making demolding difficult and causing the surface of the molded body to stick to the mold.

[0007] A technique is known for improving the impact resistance of a composition containing polyethylene terephthalate resin by using a predetermined polyethylene terephthalate resin and further incorporating 40% by weight or more of glass fibers, thereby reducing the molding shrinkage rate when injection molding using a mold at a mold temperature of 80°C, and improving the release properties of box-shaped molded products when injection molding using a mold at a mold temperature of 100°C (Patent Document 4). However, this technique requires the inclusion of 40% by weight or more of glass fibers, which results in a problem of increased product weight. Furthermore, the use of glass fibers accelerates screw wear during mixing and molding. In addition, the use of glass fibers causes fiber orientation, which can lead to orientation in the molded product and cause defects in properties depending on the shape.

[0008] On the other hand, thermoplastic polyester resins have the problem of being prone to becoming brittle due to crystallization, which can lead to a decrease in impact resistance.

[0009] Japanese Patent Publication No. 2002-86553, Japanese Patent Publication No. 11-504371, Japanese Patent Publication No. 2024-33008, International Publication No. 2023 / 100895

[0010] The present invention aims to provide a polyester resin composition containing an aromatic polyester resin, wherein the molded article obtained by molding exhibits excellent heat resistance, suppressed deformation, and excellent impact resistance. Furthermore, the invention aims to provide a polyester resin molded article obtained by molding such a polyester resin composition, which exhibits excellent heat resistance, suppressed deformation, and excellent impact resistance.

[0011] [1] The polyester resin composition according to an embodiment of the present invention is a polyester resin composition comprising an aromatic polyester resin (A), an organic crystallization accelerator (B), and a polycarbodiimide compound (C), wherein the degree of crystallinity of the polyester resin molded article obtained by injection molding at a mold temperature of 30°C using a mold that can produce a molded article with a wall thickness of 2 mm is 50% or more. [2] In the polyester resin composition described in [1] above, the aromatic polyester resin (A) may be polyethylene terephthalate. [3] In the polyester resin composition described in [1] or [2] above, the organic crystallization accelerator (B) may be a fatty acid metal salt. [4] The polyester resin composition described in any one of [1] to [3] above may contain at least one selected from the group consisting of an impact absorber (D) and a glycidyl group-containing resin (E). [5] In the polyester resin composition described in [4] above, the impact absorber (D) may be a core / shell structure in which the core portion is rubber particles. [6] In the polyester resin composition described in [4] or [5] above, the glycidyl group-containing resin (E) may contain a glycidyl methacrylate unit in its molecule. [7] In the polyester resin composition described in any one of [4] to [6] above, the glycidyl group-containing resin (E) may contain an ethylene unit. [8] In the polyester resin composition described in any one of [4] to [7] above, the glycidyl group-containing resin (E) may contain a (meth)acrylate unit. [9] The polyester resin composition described in any one of [1] to [8] above may contain an inorganic nucleating agent (F).

[10] In the polyester resin composition described in [9] above, the inorganic nucleating agent (F) may be talc.

[11] A polyester resin molded article according to an embodiment of the present invention is obtained by molding the polyester resin composition described in any one of [1] to

[10] above by injection molding using a mold.

[12] The polyester resin molded article described in

[11] above may have a degree of crystallinity of 50% or more.

[13] The polyester resin molded article described in

[11] or

[12] above may be molded at a temperature of less than 60°C in the injection molding process.

[14] The polyester resin molded article described in any one of

[11] to

[13] above may be annealed after being molded by the injection molding process.

[15] The polyester resin molded article described in

[14] above may be annealed at a temperature of 100°C to 200°C.

[0012] According to the present invention, it is possible to provide a polyester resin composition containing an aromatic polyester resin, wherein the molded article obtained by molding has excellent heat resistance, suppressed deformation of the molded article, and excellent impact resistance of the molded article. Furthermore, it is possible to provide a polyester resin molded article obtained by molding such a polyester resin composition, which has excellent heat resistance, suppressed deformation, and excellent impact resistance.

[0013] Where the term "weight" appears in this specification, it may be interpreted as "mass," which is the SI unit commonly used to indicate weight. Conversely, where the term "mass" appears in this specification, it may be interpreted as "weight," which is the unit commonly used to indicate weight.

[0014] In this specification, the expression "(meth)acrylic" means "acrylic and / or methacrylic," the expression "(meth)acrylate" means "acrylate and / or methacrylate," the expression "(meth)allyl" means "allyl and / or methallyl," and the expression "(meth)acrolein" means "acrolein and / or metacrolein."

[0015] <Polyester Resin Composition> The polyester resin composition according to the embodiment of the present invention comprises an aromatic polyester resin (A), an organic crystallization accelerator (B), and a polycarbodiimide compound (C). By having such a composition, the polyester resin composition according to the embodiment of the present invention can better exhibit the effects of the present invention.

[0016] The polyester resin composition according to the embodiment of the present invention, obtained by injection molding a polyester resin molded article with a wall thickness of 2 mm at a mold temperature of 30°C using a mold, preferably has a crystallinity of 50% or more, but may be 52% to 96%, 54% to 96%, 56% to 96%, 58% to 96%, 60% to 94%, 62% to 94%, 63% to 92%, 64% to 92%, or 65% to 90%. If the crystallinity is within the above range, deformation of the molded article can be suppressed even if annealing treatment is performed after injection molding using the polyester resin composition according to the embodiment of the present invention, and demolding from the mold in injection molding can be facilitated. If the crystallinity is too low and outside the above range, deformation of the molded article may occur when annealing treatment is performed after injection molding. If the crystallinity is too high and outside the above range, demolding from the mold in injection molding may become difficult. The degree of crystallinity referred to herein means the degree of crystallinity of a molded product after injection molding but before annealing, and is, for example, the degree of crystallinity obtained based on the measurement method described later.

[0017] The aromatic polyester resin (A) may consist of only one type or two or more types. The organic crystallization accelerator (B) may consist of only one type or two or more types. The polycarbodiimide compound (C) may consist of only one type or two or more types.

[0018] The content of aromatic polyester resin (A) in the polyester resin composition according to the embodiment of the present invention, excluding the solvent if a solvent is included, is, for example, 50% to 98% by weight, may be 60% to 98% by weight, 65% to 95% by weight, 70% to 90% by weight, 75% to 87% by weight, or 75% to 85% by weight. The effects of the present invention can be more fully expressed if the content of aromatic polyester resin (A) in the polyester resin composition according to the embodiment of the present invention falls within the above range.

[0019] The content of the organic crystallization accelerator (B) in the polyester resin composition according to the embodiment of the present invention, excluding the solvent if a solvent is included, is, for example, 0.05% to 20% by weight, may be 0.1% to 15% by weight, 0.15% to 10% by weight, 0.15% to 5% by weight, 0.15% to 3% by weight, 0.15% to 2% by weight, 0.15% to 1.5% by weight, 0.15% to 1% by weight, 0.2% to 1% by weight, or 0.2% to 0.9% by weight. If the content of the organic crystallization accelerator (B) in the polyester resin composition according to the embodiment of the present invention is within the above range, the effects of the present invention can be more fully expressed, for example, the heat resistance of the molded article obtained by molding can be improved, and the deformation of the molded article can be suppressed. If the content ratio of the organic crystallization accelerator (B) in the polyester resin composition according to the embodiment of the present invention is too low and falls outside the above range, for example, it may become difficult to promote crystallization of the molded article obtained by molding, or the heat resistance of the molded article may be reduced. If the content ratio of the organic crystallization accelerator (B) in the polyester resin composition according to the embodiment of the present invention is too high and falls outside the above range, for example, the surface of the molded article may be attached to the mold, resulting in a poor appearance of the molded article obtained by molding.

[0020] In the polyester resin composition according to the embodiment of the present invention, the content ratio of the organic crystallization accelerator (B) to 100 parts by weight of aromatic polyester resin (A) is, for example, 0.05 to 30 parts by weight, may be 0.1 to 20 parts by weight, 0.15 to 15 parts by weight, 0.2 to 10 parts by weight, 0.2 to 5 parts by weight, 0.2 to 3 parts by weight, 0.2 to 2 parts by weight, 0.2 to 1.5 parts by weight, 0.2 to 1.3 parts by weight, or 0.2 to 1.1 parts by weight. If the content ratio of the organic crystallization accelerator (B) to 100 parts by weight of aromatic polyester resin (A) is within the above range, the effects of the present invention can be more fully expressed, for example, the heat resistance of the molded article obtained by molding can be improved, and the deformation of the molded article can be suppressed. If the content ratio of the organic crystallization accelerator (B) to 100 parts by weight of the aromatic polyester resin (A) is too small and falls outside the above range, for example, it may become difficult to promote crystallization of the molded article obtained by molding, or the heat resistance of the molded article may decrease. If the content ratio of the organic crystallization accelerator (B) to 100 parts by weight of the aromatic polyester resin (A) is too large and falls outside the above range, for example, the surface of the molded article may be attached to the mold, resulting in a poor appearance of the molded article obtained by molding.

[0021] The content of the polycarbodiimide compound (C) in the polyester resin composition according to the embodiment of the present invention, excluding the solvent if a solvent is included, is, for example, 0.05% to 3% by weight, may be 0.08% to 2.5% by weight, 0.1% to 2.3% by weight, 0.1% to 2.1% by weight, 0.1% to 2.0% by weight, 0.1% to 1.9% by weight, or 0.1% to 1.8% by weight. If the content of the polycarbodiimide compound (C) in the polyester resin composition according to the embodiment of the present invention is within the above range, the effects of the present invention can be more fully expressed, for example, the impact resistance of the molded article obtained by molding can be better. If the content of the polycarbodiimide compound (C) in the polyester resin composition according to the embodiment of the present invention is too small and outside the above range, for example, the impact resistance of the molded article obtained by molding may be low. If the content of the polycarbodiimide compound (C) in the polyester resin composition according to the embodiment of the present invention is too high and falls outside the above range, for example, the melt viscosity during molding will increase, which may reduce the fluidity in the mold and cause short shots, and may also cause gelation, making it difficult to obtain stable moldability.

[0022] In the polyester resin composition according to the embodiment of the present invention, the content ratio of the polycarbodiimide compound (C) to 100 parts by weight of aromatic polyester resin (A) is, for example, 0.05 to 5 parts by weight, and may be 0.08 to 4 parts by weight, 0.1 to 3 parts by weight, 0.1 to 2.8 parts by weight, 0.1 to 2.6 parts by weight, 0.1 to 2.4 parts by weight, or 0.1 to 2.2 parts by weight. If the content ratio of the polycarbodiimide compound (C) to 100 parts by weight of aromatic polyester resin (A) is within the above range, the effects of the present invention can be more fully expressed, and for example, the impact resistance of the molded article obtained by molding can be better. If the content ratio of the polycarbodiimide compound (C) to 100 parts by weight of aromatic polyester resin (A) is too small and outside the above range, for example, the impact resistance of the molded article obtained by molding may be low. If the content ratio of polycarbodiimide compound (C) to 100 parts by weight of aromatic polyester resin (A) is too high and falls outside the above range, for example, the melt viscosity during molding will increase, which may reduce fluidity in the mold and cause short shots, and may also cause gelation, resulting in unstable moldability.

[0023] The polyester resin composition according to the embodiment of the present invention may contain at least one selected from the group consisting of an impact absorber (D) and a glycidyl group-containing resin (E). When the polyester resin composition according to the embodiment of the present invention contains at least one selected from the group consisting of an impact absorber (D) and a glycidyl group-containing resin (E), the effects of the present invention can be further exhibited, for example, the impact resistance of the molded article obtained by molding can be improved.

[0024] The shock absorber (D) may be of one type or two or more types. The glycidyl group-containing resin (E) may be of one type or two or more types.

[0025] In the polyester resin composition according to embodiments of the present invention, the content of at least one selected from the group consisting of an impact absorber (D) and a glycidyl group-containing resin (E) is, if a solvent is included, excluding the solvent, for example, 0% to 49% by weight, 0% to 40% by weight, 0% to 35% by weight, 0% to 30% by weight, 0% to 25% by weight, 1% to 20% by weight, 2% to 15% by weight, or 3% to 12% by weight.

[0026] If the polyester resin composition according to the embodiment of the present invention contains at least one selected from the group consisting of an impact absorber (D) and a glycidyl group-containing resin (E), the effects of the present invention can be further exhibited if the content ratio of the impact absorber (D) in the polyester resin composition according to the embodiment of the present invention is within the above range, for example, the impact resistance of the molded article obtained by molding can be improved. If the content ratio of at least one selected from the group consisting of an impact absorber (D) and a glycidyl group-containing resin (E) in the polyester resin composition according to the embodiment of the present invention is too high, the molded article obtained by molding may become too soft.

[0027] In the polyester resin composition according to the embodiment of the present invention, the content ratio of at least one selected from the group consisting of an impact absorber (D) and a glycidyl group-containing resin (E) to 100 parts by weight of an aromatic polyester resin (A) is, for example, 0 to 49 parts by weight, may be 0 to 45 parts by weight, 0 to 40 parts by weight, 0 to 35 parts by weight, 0 to 30 parts by weight, 1 to 25 parts by weight, 2 to 20 parts by weight, 3 to 15 parts by weight, or 4 to 13 parts by weight.

[0028] If the polyester resin composition according to an embodiment of the present invention contains at least one selected from the group consisting of an impact absorber (D) and a glycidyl group-containing resin (E), the effects of the present invention can be further exhibited if the content ratio of the impact absorber to 100 parts by weight of the aromatic polyester resin (A) is within the above range, for example, the impact resistance of the molded article obtained by molding can be further improved. If the content ratio of at least one selected from the group consisting of an impact absorber (D) and a glycidyl group-containing resin (E) to 100 parts by weight of the aromatic polyester resin (A) is too high, the molded article obtained by molding may become too soft.

[0029] The content of the shock absorber (D) in the polyester resin composition according to the embodiment of the present invention is, if a solvent is included, excluding the solvent, for example, 0% to 49% by weight, 0% to 40% by weight, 0% to 30% by weight, 0% to 25% by weight, 0% to 20% by weight, 0% to 15% by weight, 1% to 10% by weight, 2% to 10% by weight, or 3% to 10% by weight.

[0030] If the polyester resin composition according to the embodiment of the present invention contains an impact absorber (D), the effects of the present invention can be further exhibited if the content ratio of the impact absorber (D) in the polyester resin composition according to the embodiment of the present invention is within the above range, for example, the impact resistance of the molded article obtained by molding can be improved. If the content ratio of the impact absorber (D) in the polyester resin composition according to the embodiment of the present invention is too high, the molded article obtained by molding may become too soft.

[0031] In the polyester resin composition according to the embodiment of the present invention, the content ratio of the shock absorber (D) to 100 parts by weight of the aromatic polyester resin (A) is, for example, 0 to 49 parts by weight, and may be 0 to 40 parts by weight, 0 to 30 parts by weight, 0 to 20 parts by weight, 0 to 15 parts by weight, 1 to 10 parts by weight, 2 to 10 parts by weight, or 3 to 10 parts by weight.

[0032] When the polyester resin composition according to an embodiment of the present invention contains an impact absorber (D), if the content ratio of the impact absorber (D) to 100 parts by weight of the aromatic polyester resin (A) is within the above range, the effects of the present invention can be further exhibited, and for example, the impact resistance of the molded article obtained by molding can be improved. If the content ratio of the impact absorber (D) to 100 parts by weight of the aromatic polyester resin (A) is too high, the molded article obtained by molding may become too soft.

[0033] In the polyester resin composition according to embodiments of the present invention, the content of the glycidyl group-containing resin (E) is, excluding the solvent if a solvent is included, for example, 0% to 49% by weight, 0% to 40% by weight, 0% to 30% by weight, 0% to 20% by weight, 0.1% to 15% by weight, 0.5% to 12% by weight, 0.8% to 10% by weight, or 1% to 9% by weight.

[0034] If the polyester resin composition according to the embodiment of the present invention contains a glycidyl group-containing resin (E), the effects of the present invention can be further exhibited if the content ratio of the glycidyl group-containing resin (E) in the polyester resin composition according to the embodiment of the present invention is within the above range, for example, the impact resistance of the molded article obtained by molding can be improved. If the content ratio of the glycidyl group-containing resin (E) in the polyester resin composition according to the embodiment of the present invention is too high, the molded article obtained by molding may become too soft.

[0035] In the polyester resin composition according to embodiments of the present invention, the content ratio of the glycidyl group-containing resin (E) to 100 parts by weight of the aromatic polyester resin (A) is, for example, 0 to 49 parts by weight, and may be 0 to 40 parts by weight, 0 to 30 parts by weight, 0 to 20 parts by weight, 0.1 to 15 parts by weight, 0.3 to 15 parts by weight, 0.5 to 15 parts by weight, 0.8 to 12 parts by weight, 1.0 to 12 parts by weight, or 1.2 to 12 parts by weight.

[0036] When the polyester resin composition according to the embodiment of the present invention contains the glycidyl group-containing resin (E), if the content ratio of the glycidyl group-containing resin (E) to 100 parts by weight of the aromatic polyester resin (A) is within the above range, the effects of the present invention can be further expressed. For example, the impact resistance of the molded body obtained by molding can be more excellent. If the content ratio of the glycidyl group-containing resin (E) to 100 parts by weight of the aromatic polyester resin (A) is too large, the molded body obtained by molding may become too soft.

[0037] The polyester resin composition according to one preferred embodiment (Embodiment 1) of the present invention contains an aromatic polyester resin (A), an organic crystallization accelerator (B), and a polycarbodiimide compound (C).

[0038] The polyester resin composition according to another preferred embodiment (Embodiment 2) of the present invention contains an aromatic polyester resin (A), an organic crystallization accelerator (B), a polycarbodiimide compound (C), and an impact absorber (D).

[0039] The polyester resin composition according to still another preferred embodiment (Embodiment 3) of the present invention contains an aromatic polyester resin (A), an organic crystallization accelerator (B), a polycarbodiimide compound (C), and a glycidyl group-containing resin (E).

[0040] The polyester resin composition according to still another preferred embodiment (Embodiment 4) of the present invention contains an aromatic polyester resin (A), an organic crystallization accelerator (B), a polycarbodiimide compound (C), an impact absorber (D), and a glycidyl group-containing resin (E).

[0041] The polyester resin composition according to the embodiment of the present invention may contain an inorganic crystal nucleating agent (F).

[0042] The inorganic crystal nucleating agent (F) may be only one kind or two or more kinds.

[0043] The content of the inorganic nucleating agent (F) in the polyester resin composition according to the embodiment of the present invention is, if a solvent is included, excluding the solvent, for example, 0% to 40% by weight, 0% to 30% by weight, 0% to 20% by weight, 0% to 15% by weight, 1% to 15% by weight, 2% to 20% by weight, 2% to 15% by weight, or 3% to 15% by weight.

[0044] If the polyester resin composition according to the embodiment of the present invention contains an inorganic nucleating agent (F), the effects of the present invention can be further exhibited if the content ratio of the inorganic nucleating agent (F) in the polyester resin composition according to the embodiment of the present invention is within the above range. For example, the heat resistance of the molded article obtained by molding can be improved, and the deformation of the molded article can be suppressed. If the content ratio of the inorganic nucleating agent (F) in the polyester resin composition according to the embodiment of the present invention is too high, the appearance of the molded article obtained by molding may be poor, for example, the surface of the molded article may be attached to the mold.

[0045] In the polyester resin composition according to the embodiment of the present invention, the content ratio of inorganic crystal nucleating agent (F) to 100 parts by weight of aromatic polyester resin (A) is, for example, 0 to 49 parts by weight, and may be 0 to 40 parts by weight, 0 to 30 parts by weight, 0 to 20 parts by weight, 0 to 15 parts by weight, 1 to 15 parts by weight, 2 to 15 parts by weight, 3 to 15 parts by weight, 3.5 to 12 parts by weight, or 4.0 to 10 parts by weight.

[0046] When the polyester resin composition according to an embodiment of the present invention contains an inorganic nucleating agent (F), if the content ratio of the inorganic nucleating agent (F) to 100 parts by weight of aromatic polyester resin (A) is within the above range, the effects of the present invention can be further exhibited, for example, the heat resistance of the molded article obtained by molding can be improved, and the deformation of the molded article can be suppressed. If the content ratio of the inorganic nucleating agent (F) to 100 parts by weight of aromatic polyester resin (A) is too high, for example, the surface of the molded article may be taken to the mold side, which may result in a poor appearance of the molded article obtained by molding.

[0047] The polyester resin composition according to the embodiment of the present invention may contain any other suitable components other than those described above, to the extent that they do not impair the effects of the present invention. The content of the other components in the polyester resin composition according to the embodiment of the present invention may be, for example, 0% to 49% by weight, 0% to 40% by weight, 0% to 30% by weight, 0% to 20% by weight, 0% to 10% by weight, 0% to 5% by weight, 0% to 3% by weight, 0% to 1% by weight, or substantially 0% by weight.

[0048] Other components include, for example, pigments, dyes, fillers, reinforcing agents, heat stabilizers, light stabilizers, antioxidants, UV inhibitors, plasticizers, flame retardants, antistatic agents, mold release agents, and foaming agents. These other components may be present individually or in combination of two or more types.

[0049] The polyester resin composition according to the embodiment of the present invention can be manufactured by any suitable method, such as a method generally known as a method for manufacturing resin compositions. Typical such manufacturing methods include manufacturing by melt kneading.

[0050] As for the melt-mixing method, for example, the ingredients to be blended are uniformly dry-blended using a Henschel mixer, ribbon blender, V-type blender, tumbler, etc., and then melt-mixed using a single-screw or multi-screw extruder, roll, Banbury mixer, Laboplast mill (Brabender), etc. The ingredients to be blended may be added separately or sequentially, while maintaining the supply ratio.

[0051] The melting and kneading temperature can be appropriately selected depending on the type of components to be blended, the proportion of components to be blended, the type of equipment used for melting and kneading, etc. In order to better express the effects of the present invention, the melting and kneading temperature is preferably set to a temperature above the melting point of the component with the highest melting point among the components to be blended, and more preferably (the melting point + 5°C) to (the melting point + 40°C).

[0052] After melting and kneading, for example, the molten resin may be extruded from a strand die to form strands, which are then cooled in a water tank and cut into pellets using a pelletizer.

[0053] <Aromatic Polyester Resin (A)> Any suitable aromatic polyester resin can be used as aromatic polyester resin (A) as long as it does not impair the effects of the present invention. Examples of aromatic polyester resin (A) include polymers or copolymers obtained by a condensation reaction mainly composed of aromatic dicarboxylic acid (or its ester-forming derivative) and diol (or its ester-forming derivative) and / or hydroxycarboxylic acid.

[0054] Examples of aromatic dicarboxylic acids include terephthalic acid, isophthalic acid, orthophthalic acid, 2,6-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, bis(p-carboxyphenyl)methane, anthracenedicarboxylic acid, 4,4'-diphenyldicarboxylic acid, 1,2-bis(phenoxy)ethane-4,4'-dicarboxylic acid, and 5-sodium sulfisoisophthalic acid. There may be only one aromatic dicarboxylic acid or two or more.

[0055] Aliphatic dicarboxylic acids and alicyclic dicarboxylic acids may be used in combination with aromatic dicarboxylic acids. Examples of aliphatic dicarboxylic acids include adipic acid, sebacic acid, azelaic acid, and dodecanedionic acid. Examples of alicyclic dicarboxylic acids include 1,3-cyclohexanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid. There may be only one aliphatic dicarboxylic acid or two or more aliphatic dicarboxylic acids. There may be only one alicyclic dicarboxylic acid or two or more aliphatic dicarboxylic acids.

[0056] Examples of diols include aliphatic diols having 2 to 20 carbon atoms, specifically ethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, decamethylene glycol, cyclohexanedimethanol, and cyclohexanediol. There may be only one diol or two or more diols.

[0057] Examples of aromatic polyester resins (A) include, for example, polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polycyclohexanedimethylene terephthalate, polyhexylene terephthalate, and other polyalkylene terephthalates, polyethylene-2,6-naphthalenedicarboxylate, polybutylene-2,6-naphthalenedicarboxylate, polyethylene-1,2-bis(phenoxy)ethane-4,4'-dicarboxylate, polyethylene isophthalate / terephthalate, polybutylene isophthalate / terephthalate, polybutylene terephthalate / decanedicarboxylate, poly(ethylene terephthalate / cyclohexanedimethylene terephthalate), and polyethylene-4,4'-dicarboxylate / terephthalate. In terms of further exhibiting the effects of the present invention, polyethylene terephthalate, polybutylene terephthalate, and polyethylene-2,6-naphthalenedicarboxylate are preferred as polyester resins (A), and polyethylene terephthalate (PET) is more preferred.

[0058] As the aromatic polyester resin (A), recycled aromatic polyester resins may be used, typically recycled PET.

[0059] The aromatic polyester resin (A) may be recycled PET alone or a blend with virgin PET.

[0060] As recycled PET, generally known recycled PET can be used. Such recycled PET can be obtained, for example, by collecting used PET film or used waste PET bottles and other PET containers, and processing them through purification or other means.

[0061] <Organic crystallization accelerator (B)> As the organic crystallization accelerator (B), any suitable organic crystallization accelerator can be used, as long as it does not impair the effects of the present invention.

[0062] Examples of organic crystallization accelerators (B) include compounds that melt at temperatures below 300°C.

[0063] Examples of organic crystallization accelerators (B) include fatty acid metal salts, ionomers, and ester oligomers, and fatty acid metal salts are preferred from the viewpoint of being able to better express the effects of the present invention.

[0064] As the fatty acid metal salt, any suitable fatty acid metal salt can be used as long as it does not impair the effects of the present invention. Examples of such fatty acid metal salts include alkali metal salts or alkaline earth metal salts of fatty acids having 6 to 30 carbon atoms in the alkyl or alkenyl group.

[0065] Examples of fatty acids with 6 to 30 carbon atoms in an alkyl or alkenyl group include, for example, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid (caprylic acid), decanoic acid (capric acid), dodecanoic acid (lauric acid), todecanoic acid (tridecyl acid), tetradecanoic acid (myristic acid), pentadecanoic acid, hexadecanoic acid (palmitic acid), heptadecanoic acid, octadecanoic acid (stearic acid), oleic acid, nonadecanoic acid, eicosanoic acid, linoleic acid, docosanoic acid, linolenic acid, tetracosanoic acid, hexacosanoic acid, montanic acid, eicosenoic acid, octacosanoic acid, and nonacosanoic acid. Among these, from the viewpoint of more effectively exhibiting the effects of the present invention, fatty acids with 10 to 26 carbon atoms in the alkyl or alkenyl group are preferred, fatty acids with 14 to 24 carbon atoms in the alkyl or alkenyl group are preferred, and octadecanoic acid (stearic acid) and oleic acid are more preferred.

[0066] Examples of alkali metal salts include lithium salts, sodium salts, and potassium salts. Examples of alkaline earth metal salts include magnesium salts and calcium salts.

[0067] Ionomers are typically obtained by neutralizing a copolymer of an olefin and at least one selected from the group consisting of α,β-unsaturated carboxylic acids and unsaturated carboxylic acid esters with a metal or metal ion. Any suitable ionomer can be used as the ionomer, as long as it does not impair the effects of the present invention. Examples of such ionomers include olefin-based ionomers, styrene-based ionomers, and ABS-based ionomers, and olefin-based ionomers are preferred from the viewpoint of better exhibiting the effects of the present invention.

[0068] As the olefin ionomer, any suitable olefin ionomer can be used as long as it does not impair the effects of the present invention. Examples of such olefin ionomers include copolymers of (at least one selected from the group consisting of ethylene and propylene) / (at least one selected from the group consisting of α,β-unsaturated carboxylic acids and unsaturated carboxylic acid esters). Examples of α,β-unsaturated carboxylic acid monomers include acrylic acid and methacrylic acid. Examples of α,β-unsaturated carboxylic acid ester monomers include methyl esters, ethyl esters, propyl esters, butyl esters, pentyl esters, hexyl esters, heptyl esters, octyl esters, nonyl esters, and decyl esters of α,β-unsaturated carboxylic acids. In such copolymers, the content of at least one unit selected from the group consisting of ethylene and propylene is, for example, 10 mol% to 90 mol%, and may be 20 mol% to 80 mol%.

[0069] Examples of metals and metal ions used in ionomers include Na, K, Cu, Mg, Ca, Ba, Zn, Cd, Al, Fe, Co, Ni, and their ions.

[0070] Examples of olefin-based ionomers include, for example, ethylene / methacrylic acid copolymer ionomers, and more specifically, ethylene / methacrylic acid / acrylic acid ester copolymer ionomers.

[0071] Examples of commercially available olefin-based ionomers include the Hymilan® series manufactured by Mitsui Dow Polychemical Co., Ltd.

[0072] As the ester oligomer, any suitable ester oligomer can be used, as long as it does not impair the effects of the present invention. Examples of such ester oligomers include the Polysizer series manufactured by DIC Corporation.

[0073] <Polycarbodiimide compound (C)> The ends of aromatic polyester resins (A) typically contain carboxylic acid groups or hydroxyl groups. Therefore, in order to increase the apparent molecular weight of aromatic polyester resins (A) and improve their mechanical properties, we investigated resins that have high reactivity with carboxylic acid groups and hydroxyl groups, or resins that are compatible with them. As a result, we found that by adopting polycarbodiimide compound (C) as one component of the polyester resin composition according to the embodiment of the present invention, the effects of the present invention can be realized, and for example, excellent impact resistance can be achieved in the molded article obtained by molding.

[0074] The molecular structure of the polycarbodiimide compound (C) may be aromatic, alicyclic, or aliphatic, and may also be cyclic.

[0075] The weight-average molecular weight of the polycarbodiimide compound (C) is preferably 800 to 5800, and more preferably 1000 to 5500. The effects of the present invention can be better expressed if the weight-average molecular weight of the polycarbodiimide compound (C) is within the above range. If the weight-average molecular weight of the polycarbodiimide compound (C) is outside the above range and is low, it may not be possible to create a bulky structure even by grafting with the aromatic polyester resin (A). If the weight-average molecular weight of the polycarbodiimide compound (C) is outside the above range and is high, the reactivity of the polycarbodiimide compound (C) may decrease.

[0076] Examples of polycarbodiimide compounds (C) include poly(4,4'-dicyclohexylmethanecarbodiimide), poly(4,4'-diphenylmethanecarbodiimide), poly(3,5'-dimethyl-4,4'-diphenylmethanecarbodiimide), poly(p-phenylenecarbodiimide), poly(m-phenylenecarbodiimide), poly(naphthylenecarbodiimide), poly(1,3-diisopropylphenylenecarbodiimide), poly(1-methyl-3,5-diisopropylphenylenecarbodiimide), poly(1,3,5-triethylphenylenecarbodiimide), and poly(triisopropylphenylenecarbodiimide).

[0077] <Shock Absorber (D)> Any suitable shock absorber can be used as the shock absorber (D) as long as it does not impair the effects of the present invention. Typical shock absorbers include rubber components. Examples of rubber components include conjugated diene polymers such as polybutadiene, polyisoprene, butadiene-polyisoprene copolymer, acrylonitrile-isoprene copolymer, (meth)acrylic acid ester-butadiene copolymer, (meth)acrylic acid ester-butadiene-styrene copolymer, and (meth)acrylic acid ester-isoprene copolymer; hydrogenated conjugated diene polymers; olefin rubbers such as ethylene-propylene copolymer; (meth)acrylic rubbers such as poly(meth)acrylic acid ester; silicone-(meth)acrylic polymer composite rubbers; and polyorganosiloxanes. Among these, conjugated diene polymers, hydrogenated conjugated diene polymers, (meth)acrylic rubbers, and silicone-(meth)acrylic polymer composite rubbers are preferred. Examples of (meth)acrylic acid esters used to obtain (meth)acrylic rubber include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and octyl (meth)acrylate.

[0078] The shock absorber (D) may have a crosslinked molecular chain structure in order to exhibit rubber elasticity. The shock absorber (D) may have a rubber layer and an adjacent layer, and the molecular chains of the rubber layer and the molecular chains in the adjacent layer may be grafted by chemical bonds.

[0079] The shock absorber (D) is preferably a core / shell type structure having a core portion and a shell portion, and the core portion may contain a rubber component. Such a core / shell type structure may be obtained, for example, by graft polymerization of polymerizable monomers for forming the shell portion in the presence of a polymer forming the core portion.

[0080] Examples of polymers that form the core include the aforementioned rubber component.

[0081] Examples of polymerizable monomers that can be used to form the shell include (meth)acrylic acid esters such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, amyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, cyclohexyl (meth)acrylate, octyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, octadecyl (meth)acrylate, phenyl (meth)acrylate, benzyl (meth)acrylate, naphthyl (meth)acrylate, and isovonyl (meth)acrylate; (meth)acrylic acids such as acrylic acid and methacrylic acid; aromatic vinyl compounds such as styrene and α-methylstyrene; and acrylonitrile. The shell layer may also be a modified product (e.g., epoxy modified) of a polymer obtained from these polymerizable monomers.

[0082] Examples of shell materials include polymers obtained from at least one selected from the group consisting of (meth)acrylic acid esters and styrene, and modified products of such polymers (e.g., epoxy-modified polymers).

[0083] The core portion in the core / shell type structure can be any appropriate content as long as it does not impair the effects of the present invention. For example, such a content may be in the range of 25% to 90% by weight, or in the range of 40% to 80% by weight. If the core portion content is too low, flexibility will be insufficient, and sufficient impact resistance may not be achieved. If the core portion content is too high, the shell portion content will be relatively too low, reducing compatibility with the aromatic polyester resin (A), and potentially leading to a decrease in interfacial bonding strength and uniform dispersion, which may prevent the achievement of sufficient impact resistance.

[0084] As a core / shell type structure in which the aforementioned rubber component is used as the polymer forming the core and a polymer obtained from at least one selected from the group consisting of (meth)acrylic acid ester and styrene, or a modified product of said polymer (e.g., epoxy modified), is used as the shell, commercially available core / shell type structures can also be used. Examples of commercially available core / shell-type structures include the "Metabren® C" series (manufactured by Mitsubishi Chemical Corporation), the "Metabren® E" series (manufactured by Mitsubishi Chemical Corporation), the "Metabren® W" series (manufactured by Mitsubishi Chemical Corporation), the "Metabren® S" series (manufactured by Mitsubishi Chemical Corporation), the "KaneAce® B" series (manufactured by Kaneka Corporation), the "KaneAce® FM" series (manufactured by Kaneka Corporation), and the "KaneAce® M" series (manufactured by Kaneka Corporation). Among these, the "Metabren® S" series (manufactured by Mitsubishi Chemical Corporation) and the "KaneAce® FM" series (manufactured by Kaneka Corporation) are preferably adopted.

[0085] The core / shell structure has an average particle diameter of, for example, 10 nm to 1000 nm, but may also be 30 nm to 750 nm or 50 nm to 500 nm. By setting the average particle diameter of the core / shell structure within the above range, impact resistance and moldability can be improved.

[0086] <Glycidyl Group-Containing Resin (E)> The ends of aromatic polyester resins (A) typically contain carboxylic acid groups or hydroxyl groups. Therefore, in order to increase the apparent molecular weight of aromatic polyester resins (A) and improve their mechanical properties, we investigated resins that have high reactivity with carboxylic acid groups and hydroxyl groups, or resins that are compatible with them. As a result, we found that by adopting a glycidyl group-containing resin having glycidyl groups as one component of the polyester resin composition according to the embodiment of the present invention, the effects of the present invention can be more fully expressed, and for example, the molded article obtained by molding can exhibit better impact resistance.

[0087] From the viewpoint of more effectively exhibiting the effects of the present invention, the glycidyl group-containing resin (E) preferably contains glycidyl methacrylate units within its molecule. The content of glycidyl methacrylate units within the molecule of the glycidyl group-containing resin (E) is, for example, 0.5% to 30% by weight, may be 1% to 27% by weight, 1.5% to 25% by weight, 2% to 20% by weight, 2.5% to 15% by weight, or 3% to 10% by weight.

[0088] The glycidyl group-containing resin (E) preferably contains ethylene units in its molecule, from the viewpoint of more effectively exhibiting the effects of the present invention. The content of ethylene units in the molecule of the glycidyl group-containing resin (E) is, for example, 30% to 99% by weight, may be 40% to 98% by weight, 50% to 98% by weight, 60% to 97% by weight, 70% to 97% by weight, or 75% to 97% by weight.

[0089] The glycidyl group-containing resin (E) may contain (meth)acrylate units within its molecule. The content of (meth)acrylate units within the molecule of the glycidyl group-containing resin (E) is, for example, 0.5% to 60% by weight, may be 5% to 50% by weight, 8% to 40% by weight, 10% to 35% by weight, or 15% to 35% by weight.

[0090] Examples of glycidyl group-containing resins (E) having glycidyl methacrylate units and ethylene units in their molecules include ethylene (E)-glycidyl methacrylate (GMA) copolymer, ethylene (E)-glycidyl methacrylate (GMA)-methyl acrylate (MA) copolymer, ethylene (E)-glycidyl methacrylate (GMA)-1-hexene (H) copolymer, ethylene (E)-glycidyl methacrylate (GMA)-vinyl acetate (VA) copolymer, and copolymers having an ethylene (E)-glycidyl methacrylate (GMA) copolymer structure as the main chain and a butyl acrylate (BA)-methyl methacrylate (MA) copolymer as the side chain.

[0091] <Inorganic nucleating agent (F)> Any suitable inorganic nucleating agent can be used as the inorganic nucleating agent (F), as long as it does not impair the effects of the present invention.

[0092] Examples of inorganic nucleating agents (F) include compounds that do not melt unless the temperature exceeds 300°C.

[0093] Examples of inorganic nucleating agents (F) include talc, kaolin, montmorillonite, synthetic mica, clay, zeolite, silica, graphite, carbon black, zinc oxide, magnesium oxide, titanium oxide, calcium sulfide, boron nitride, calcium carbonate, barium sulfate, aluminum oxide, neodymium oxide, metal salts of phenylphosphonate, and organic modifiers of these materials. From the viewpoint of better exhibiting the effects of the present invention, talc is preferred as the inorganic nucleating agent (F).

[0094] The particle size D50 (laser diffraction method) of the inorganic nucleating agent (F) is, for example, 0.1 μm to 50 μm, and may also be 0.5 μm to 20 μm, or 1 μm to 10 μm.

[0095] <Polyester Resin Molded Article> A polyester resin molded article according to an embodiment of the present invention is obtained by molding a polyester resin composition according to an embodiment of the present invention by injection molding using a mold.

[0096] Since the polyester resin molded article according to the embodiment of the present invention is obtained by molding the polyester resin composition according to the embodiment of the present invention by injection molding using a mold, the degree of crystallinity is preferably 50% or more, but may be 52% to 96%, 54% to 96%, 56% to 96%, 58% to 96%, 60% to 94%, 62% to 94%, 63% to 92%, 64% to 92%, or 65% to 90%. If the degree of crystallinity is within the above range, deformation of the molded article can be suppressed even if annealing is performed after injection molding, and demolding from the mold in injection molding can be facilitated. If the degree of crystallinity is too low and outside the above range, deformation of the molded article may occur when annealing is performed after injection molding. If the degree of crystallinity is too high and outside the above range, demolding from the mold in injection molding may become difficult. The degree of crystallinity referred to herein means the degree of crystallinity of a molded product after injection molding but before annealing, and is, for example, the degree of crystallinity obtained based on the measurement method described later.

[0097] As for the injection molding method using a mold, any suitable method generally known as an injection molding method using a mold for polyester resin compositions can be adopted, as long as it does not impair the effects of the present invention.

[0098] In the polyester resin molded article according to the embodiment of the present invention, from the viewpoint of further exhibiting the effects of the present invention, the mold temperature in injection molding may be, for example, less than 60°C, less than 50°C, less than 40°C, less than 35°C, less than 32°C, 30°C or lower, or less than 30°C. The lower limit of the above mold temperature can be set to any appropriate lower limit as long as it is a lower limit that can be used in injection molding, for example, it may be 15°C. The polyester resin molded article according to the embodiment of the present invention can achieve the above degree of crystallinity even when using a mold with such a low mold temperature, shrinkage of the molded article is less likely to occur, demolding is easier, and the problem of the surface of the molded article being taken to the mold side is less likely to occur.

[0099] The polyester resin molded article according to the embodiment of the present invention may be annealed after being molded by the injection molding described above. The annealing temperature may be, for example, 100°C to 200°C. Even after annealing, the polyester resin molded article according to the embodiment of the present invention can suppress shrinkage and deformation of the molded article.

[0100] The present invention will be specifically described below with reference to examples, but the present invention is not limited in any way to these examples. The test and evaluation methods in the examples are as follows. When "parts" is written, it means "parts by weight" unless otherwise specified, and when "%" is written, it means "percent by weight" unless otherwise specified.

[0101] <Preparation of dumbbell-shaped molded bodies> The polyester resin composition pellets obtained in the examples and comparative examples were dried at 120°C for 5 hours using a dehumidifying dryer. Dumbbell-shaped molded bodies (ISO 527-2-5A test piece, width of the narrowest part 4 mm, thickness 2 mm) were then produced by injection molding using a mold that can produce molded bodies with a wall thickness of 2 mm (cylinder temperature 285°C, mold temperature 30°C), with the central part being narrow and both ends being wide.

[0102] <Degree of Crystallinity of Dumbbell-Shaped Molded Body> A sample was taken from the finest part of the dumbbell-shaped molded body and measured using DSC under a nitrogen atmosphere at a heating rate of 10°C / min. Based on the total heat quantity Hc of the exothermic peaks and the total heat quantity Hm of the endothermic peaks obtained, the degree of crystallinity Xc of the dumbbell-shaped molded body was calculated using the following formula (1): Xc = 100 × (Hm - Hc) / Hm (1)

[0103] <Evaluation of Demolding Properties of Dumbbell-Shaped Molded Products> In the production of dumbbell-shaped molded products, the demolding properties when removing the molded product from the mold were evaluated according to the following criteria. ○: The molded product could be easily removed from the mold. ×: The product was stuck to the mold and could not be demolded, or the runner broke, or resin components were transferred to the mold.

[0104] <Evaluation of the appearance of dumbbell-shaped molded products after demolding> The appearance of the dumbbell-shaped molded products was evaluated according to the following criteria. ◎: No appearance defects (burrs, sink marks, gas leak marks, etc.) and no deformation. 〇: No deformation, but some appearance defects (burrs, sink marks, gas leak marks, etc.) that do not hinder use. ×: Appearance defects (burrs, sink marks, gas leak marks, etc.) or deformation that hinder use.

[0105] <Deformation Evaluation of Dumbbell-Shaped Molded Body After Annealing> The handle portion of the dumbbell-shaped molded body was supported in a cantilevered manner and placed in a dryer at 120°C or 180°C for 1 hour to perform the annealing treatment. After removing the body from the dryer in a cantilevered state and allowing it to cool, the deformation angle of the handle portion opposite the support portion was measured with a protractor and evaluated according to the following criteria. ○: The deformation angle was 20 degrees or less. ×: The deformation angle exceeded 20 degrees.

[0106] <Preparation of Container-Shaped Molded Products> The polyester resin composition pellets obtained in the examples and comparative examples were dried at 120°C for 5 hours using a dehumidifying dryer, and then injection molded. The injection molding was performed using a mold with a container shape of 100 mm x 100 mm base, 20 mm height, a draft angle of 30 degrees, and a wall thickness of 2 mm, at a cylinder temperature of 285°C and a mold temperature of 30°C or 80°C to produce container-shaped molded products.

[0107] <Evaluation of Demolding Properties of Container-Shaped Molded Products> In the production of container-shaped molded products, the demolding properties when removing the molded product from the mold were evaluated according to the following criteria. ○: The molded product could be easily removed from the mold. ×: The product was stuck to the mold and could not be demolded, or the runner broke, or resin components were transferred to the mold.

[0108] <Evaluation of the appearance of the molded container after demolding> The appearance of the molded container was evaluated according to the following criteria. ◎: No surface defects (burrs, sink marks, gas leak marks, etc.) and no deformation. 〇: No deformation, but some surface defects (burrs, sink marks, gas leak marks, etc.) that do not hinder use. ×: Surface defects (burrs, sink marks, gas leak marks, etc.) or deformation that hinder use.

[0109] <Evaluation of Deformation after Annealing Treatment of Container-shaped Molded Body> The container-shaped molded body was subjected to an annealing treatment for 1 hour in an atmosphere of 120°C without load and in a stationary state. After the 1-hour annealing treatment, it was evaluated according to the following criteria. 〇: The shape was maintained without distortion and remained in its original shape. ×: The shape was distorted.

[0110] <Izod Impact Strength> The pellets of the polyester resin compositions obtained in the examples and comparative examples were dried at 120°C for 5 hours using a dehumidifying dryer, and test pieces of 4 mm × 10 mm × 80 mm were produced by injection molding (cylinder temperature 285°C, mold temperature 30°C). The obtained test pieces were put into a dryer with an atmosphere of 120°C or 180°C for annealing treatment until the crystallinity reached 100%. The charging time into the dryer was 2 hours. Then, notch machining was performed and the test was carried out according to JIS-K7110-1A type. The Izod impact strength is preferably 2.5 kJ / m 2 or more, and may be 2.5 kJ / m 2 or more, and may be 2.9 kJ / m 2 or more, and may be 3.3 kJ / m 2 or more, and may be 3.5 kJ / m 2 or more. If the Izod impact strength is too small outside the above range, there is a risk of breakage even with a slight impact. Although the Izod impact strength can be more excellent in fracture toughness as it is larger, if it is too large, there is a risk that the molded body becomes too soft. From this perspective, the Izod impact strength may be, for example, 20 kJ / m 2 or less, and may be 15 kJ / m 2 or less, and may be 10 kJ / m 2 or less, and may be 8.5 kJ / m 2 or less, and may be 7 kJ / m 2 or less, and may be 5.5 kJ / m 2 or less, and may be 5.1 kJ / m 2 or less.

[0111] <Steel Ball Drop Test> The molded container was placed upside down, and a 50g steel ball was dropped from a height of 1m onto the center of its bottom three times. The condition of the molded product was then checked. The following criteria were used for evaluation. ○: No damage (even if whitening occurred, it was marked as ○ if there was no damage). ×: Cracks occurred.

[0112] <Materials Used> The materials used in the examples and comparative examples are as follows: [Aromatic Polyester Resin (A)] ・Aromatic polyester resin (A1): Recycled PET, MVR = (Load 2.16 kg, Temperature 285°C) = 120 cm 3 / 10 minutes - Aromatic polyester resin (A2): Recycled PET, MVR = (Load 2.16 kg, Temperature 285°C) = 100 cm 3 / 10 minutes Note: MVR was measured using an apparatus conforming to JIS K7210. [Organic crystallization accelerator (B)] ・Organic crystallization accelerator (B1): Ester oligomer, trade name "Polysizer A-55", manufactured by DIC Corporation ・Organic crystallization accelerator (B2): Olefin ionomer, trade name "Hymiran 1707", manufactured by Mitsui Dow Polychemical Co., Ltd. ・Organic crystallization accelerator (B3): Fatty acid metal salt, sodium oleate ・Organic crystallization accelerator (B4): Fatty acid metal salt, sodium stearate ・Organic crystallization accelerator (B5): Fatty acid metal salt, calcium stearate ・Organic crystallization accelerator (B6): Fatty acid metal salt, magnesium stearate [Polypolycarbodiimide compound (C)] ・Polypolycarbodiimide compound (C1): Trade name "Carbodilite LA-1", manufactured by Nisshinbo Chemical, Mw = approximately 2000 - Polypolycarbodiimide compound (C2): Trade name "Carbodilite HMV-15CA", manufactured by Nisshinbo Chemical, Mw = approximately 2000 [Shock absorber (D)] - Shock absorber (D1): Core / shell type structure, trade name "Kaneace FM-40", manufactured by Kaneka Corporation - Shock absorber (D2): Core / shell type structure, trade name "Metablen S-2030", manufactured by Mitsubishi Chemical Corporation - Shock absorber (D3): Core / shell type structure, trade name "Metablen S-2200", manufactured by Mitsubishi Chemical Corporation [Glycidyl group-containing resin (E)]・Glycidyl group-containing resin (E1): Ethylene (E)-glycidyl methacrylate (GMA) copolymer, E / GMA = 94 / 6 (weight ratio), product name "BondFirst BF-2C", manufactured by Sumitomo Chemical Co., Ltd. ・Glycidyl group-containing resin (E2): Ethylene (E)-glycidyl methacrylate (GMA)-methyl acrylate (MA) copolymer, E / GMA / MA = 67 / 6 / 27 (weight ratio), product name "BondFirst BF-7M", manufactured by Sumitomo Chemical Co., Ltd. ・Glycidyl group-containing resin (E3): Ethylene (E)-glycidyl methacrylate (GMA)-1-hexene H) Copolymer, E / GMA / H = 95 / 2 / 3 (weight ratio), product name "ET100", manufactured by Showa Denko Building Materials Co., Ltd. Glycidyl group-containing resin (E4): Ethylene (E) - Glycidyl methacrylate (GMA) copolymer, E / GMA = 81 / 19 (weight ratio), product name "Bondfast CG5001", manufactured by Sumitomo Chemical Co., Ltd. Glycidyl group-containing resin (E5): Ethylene (E) - Glycidyl methacrylate (GMA) - Vinyl acetate (VA) copolymer, E / GMA / VA = 83 / 12 / 5 (weight ratio), product name "Bondfast BF-7B", manufactured by Sumitomo Chemical Co., Ltd. [Inorganic Crystal Nucleating Agents (F)] ・Inorganic Crystal Nucleating Agent (F1): Talc, trade name "Microace SG-95", manufactured by Nippon Talc Co., Ltd., particle size D50 = 2.1 μm ・Inorganic Crystal Nucleating Agent (F2): Talc, trade name "Microace P-4", manufactured by Nippon Talc Co., Ltd., particle size D50 = 4.5 μm ・Inorganic Crystal Nucleating Agent (F3): Epoxysilane-treated talc, epoxysilane-treated version of trade name "Microace P-4", manufactured by Nippon Talc Co., Ltd., particle size D50 = 4.5 μm

[0113] [Examples 1-14, Comparative Examples 1-5] As shown in Tables 1-3, aromatic polyester resin (A), organic crystallization accelerator (B), polycarbodiimide compound (C), shock absorber (D), glycidyl group-containing resin (E), and inorganic crystal nucleating agent (F) were dry-blended in their entirety and fed into a twin-screw extruder using a quantitative feeder. The aromatic polyester resin (A) was dehumidified and dried before dry-blending. After melt-kneading, the molten resin was discharged from the strand die, and the strands were cooled by passing them through a water bath. After that, they were cut into pellets using a pelletizer to obtain polyester resin compositions (1)-(14) and (C1)-(C5). A twin-screw extruder with a screw diameter of 11 mm and L / D = 40 was used. The kneading temperature was set to a maximum setting of 275°C in the barrel section and 260°C in the die section. The screw rotation speed was 600 rpm, and the material feed rate was 2 kg / hr. The results are shown in Tables 1-3.

[0114]

[0115]

[0116]

[0117] According to the present invention, a polyester resin composition containing an aromatic polyester resin can be provided, which exhibits excellent heat resistance, suppression of deformation of the molded article, and excellent impact resistance of the molded article. For example, a polyester resin composition can be made using recycled PET as a raw material, exhibiting excellent heat resistance, excellent shape retention, and excellent impact resistance, and can be suitably used for PET recycling.

Claims

1. A polyester resin composition comprising an aromatic polyester resin (A), an organic crystallization accelerator (B), and a polycarbodiimide compound (C), wherein the degree of crystallinity of the polyester resin molded article obtained by injection molding at a mold temperature of 30°C using a mold capable of producing a molded article with a wall thickness of 2 mm is 50% or more.

2. The polyester resin composition according to claim 1, wherein the aromatic polyester resin (A) is polyethylene terephthalate.

3. The polyester resin composition according to claim 1, wherein the organic crystallization accelerator (B) is a fatty acid metal salt.

4. The polyester resin composition according to claim 1, comprising at least one selected from the group consisting of an impact absorber (D) and a glycidyl group-containing resin (E).

5. The polyester resin composition according to claim 4, wherein the shock absorber (D) is a core / shell structure in which the core portion is rubber particles.

6. The polyester resin composition according to claim 4, wherein the glycidyl group-containing resin (E) contains a glycidyl methacrylate unit in its molecule.

7. The polyester resin composition according to claim 4, wherein the glycidyl group-containing resin (E) contains an ethylene unit.

8. The polyester resin composition according to claim 4, wherein the glycidyl group-containing resin (E) comprises (meth)acrylate units.

9. The polyester resin composition according to claim 1, comprising an inorganic crystal nucleating agent (F).

10. The polyester resin composition according to claim 9, wherein the inorganic nucleating agent (F) is talc.

11. A polyester resin molded article obtained by molding a polyester resin composition according to any one of claims 1 to 10 by injection molding using a mold.

12. The polyester resin molded article according to claim 11, wherein the degree of crystallinity is 50% or more.

13. The polyester resin molded article according to claim 11, wherein the mold temperature in the injection molding is less than 60°C.

14. The polyester resin molded article according to claim 11, which has been annealed after being molded by injection molding.

15. The polyester resin molded article according to claim 14, wherein the annealing temperature is 100°C to 200°C.

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