Resin composition and molded body

Abstract

The present invention includes a poly(3-hydroxyalkanoate) resin (A) and an aliphatic aromatic polyester resin (B). The resin (A) includes: a copolymer (A1) of a 3-hydroxybutyrate unit and another hydroxyalkanoate unit, the other hydroxyalkanoate unit fraction being at least 5 mol% but less than 24 mol%, and the weight average molecular weight of the copolymer (A1) being less than 700,000; and a copolymer (A4) of a 3-hydroxybutyrate unit and another hydroxyalkanoate unit, the other hydroxyalkanoate unit fraction being at least 5 mol% but less than 24 mol%, and the weight average molecular weight being at least 700,000. The copolymer (A1) content is 25–65 wt%, the copolymer (A4) content is 5–30 wt%, and the resin (B) content is 5–30 wt%.

Description

Resin composition and molded article

[0001] The present invention relates to a resin composition containing a poly(3-hydroxyalkanoate) resin and a molded article thereof.

[0002] In recent years, environmental problems caused by discarded plastics have come into the spotlight, and it has become clear that large amounts of plastic, particularly plastics dumped in the ocean or that have entered the ocean via rivers, are drifting in the oceans on a global scale. Because such plastics retain their shape for long periods of time, they can trap and capture marine organisms, a phenomenon known as ghost fishing, and if ingested by marine organisms, can remain in their digestive tracts, causing feeding disorders, and other problems have been pointed out as having an impact on the ecosystem.

[0003] Furthermore, it has been pointed out that microplastics, which are plastics that have broken down and broken down into tiny particles due to ultraviolet rays and other factors, absorb harmful compounds in the ocean, and when marine organisms ingest these, harmful substances are introduced into the food chain.

[0004] The use of biodegradable plastics is expected to combat marine pollution caused by such plastics, but a report compiled by the United Nations Environment Programme in 2015 pointed out that plastics that can be biodegraded through compost, such as polylactic acid, cannot be expected to decompose in a short period of time in the cold ocean, and therefore cannot be used to combat marine pollution.

[0005] In this context, poly(3-hydroxyalkanoate) resins are attracting attention as a material that can solve the above problems because they are biodegradable even in seawater.

[0006] Patent Documents 1 and 2 describe that mechanical properties and the like are improved by blending the poly(3-hydroxyalkanoate) resin with an aliphatic aromatic polyester resin, typified by polybutylene adipate terephthalate (PBAT).

[0007] International Publication No. 2014 / 054278 Japanese Patent Application Laid-Open No. 2022-185793

[0008] Blending a poly(3-hydroxyalkanoate) resin with an aliphatic aromatic polyester resin can improve strength. However, the strength improvement effect is still insufficient, and there is room for further improvement. Furthermore, even if strength is improved, it has been found that the heat resistance is insufficient, and the resin tends to deform or crack under heat.

[0009] In view of the above-described current situation, the present invention aims to provide a resin composition containing a poly(3-hydroxyalkanoate)-based resin, which has high strength and is suppressed from deforming and cracking under heat, and a molded article made from the resin composition.

[0010] As a result of intensive research to solve the above-mentioned problems, the present inventors have found that by using an aliphatic aromatic polyester resin in a specific ratio and by using two types of poly(3-hydroxyalkanoate) resins having different weight-average molecular weights in specific ratios, a molded article having high strength and suppressed deformation and cracking under heating can be obtained, and have completed the present invention.

[0011] That is, the present invention provides a resin composition containing a polyester-based resin component, wherein the polyester-based resin component comprises a poly(3-hydroxyalkanoate)-based resin (A) and an aliphatic aromatic polyester-based resin (B), and the poly(3-hydroxyalkanoate)-based resin (A) comprises a copolymer (A1) of 3-hydroxybutyrate units and other hydroxyalkanoate units, in which the content of the other hydroxyalkanoate units in the total of the 3-hydroxybutyrate units and the other hydroxyalkanoate units is 5 mol% or more and less than 24 mol%, and the weight-average molecular weight is less than 700,000, and a copolymer (A4) of 3-hydroxybutyrate units and other hydroxyalkanoate units, in which the content of the other hydroxyalkanoate units in the total of the 3-hydroxybutyrate units and the other hydroxyalkanoate units is 5 mol% or more and less than 24 mol%, and the weight-average molecular weight is 700,000 or more, The present invention relates to a resin composition, in which the content of the copolymer (A1) is 25% by weight or more and 65% by weight or less, the content of the copolymer (A4) is 5% by weight or more and 30% by weight or less, and the content of the aliphatic aromatic polyester resin (B) is 5% by weight or more and 30% by weight or less, based on the total amount of the poly(3-hydroxyalkanoate) resin (A) and the aliphatic aromatic polyester resin (B). The present invention also relates to a molded article containing the resin composition.

[0012] According to the present invention, it is possible to provide a resin composition containing a poly(3-hydroxyalkanoate)-based resin, which has high strength and is suppressed in deformation and cracking under heat, and a molded article made from the resin composition. Furthermore, according to a preferred embodiment of the present invention, it is possible to provide a resin composition and molded article that are practically excellent because they have a good balance between strength and toughness and a wide range of deformability while maintaining hardness.

[0013] A graph showing the test force on the vertical axis and the displacement on the horizontal axis, obtained from a bending test to measure fracture energy

[0014] Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to the following embodiments.

[0015] One embodiment of the present invention is a resin composition containing a polyester-based resin component. The resin composition can be suitably used to produce a molded article. The polyester-based resin component contains at least a poly(3-hydroxyalkanoate)-based resin (A) and an aliphatic-aromatic polyester-based resin (B).

[0016] (Poly(3-hydroxyalkanoate)-based resin (A)) The poly(3-hydroxyalkanoate)-based resin is a polymer having a 3-hydroxyalkanoate unit, and specifically, is preferably a polymer containing a unit represented by the following general formula (1): [—CHR—CH ２ -CO-O-] (1) In the general formula (1), R is C ｐ H ２ｐ＋１ where p is an integer of 1 to 15. Examples of R include linear or branched alkyl groups such as methyl, ethyl, propyl, methylpropyl, butyl, isobutyl, t-butyl, pentyl, and hexyl. p is preferably an integer of 1 to 10, and more preferably an integer of 1 to 8.

[0017] The poly(3-hydroxyalkanoate) resin is preferably a poly(3-hydroxyalkanoate) resin produced by a microorganism, in which all 3-hydroxyalkanoate units are contained as (R)-3-hydroxyalkanoate units.

[0018] The poly(3-hydroxyalkanoate) resin preferably contains 3-hydroxyalkanoate units (particularly units represented by general formula (1)) in an amount of 50 mol % or more, more preferably 60 mol % or more, and even more preferably 70 mol % or more of the total structural units. The poly(3-hydroxyalkanoate) resin may contain only 3-hydroxyalkanoate units as structural units of the polymer, or may contain one or more types of 3-hydroxyalkanoate units as well as other units (e.g., 4-hydroxyalkanoate units).

[0019] The poly(3-hydroxyalkanoate) resin may be a homopolymer or copolymer containing 3-hydroxybutyrate (hereinafter sometimes referred to as 3HB) units. In particular, it is preferable that all of the 3-hydroxybutyrate units are (R)-3-hydroxybutyrate units. Furthermore, it is preferable that the poly(3-hydroxyalkanoate) resin is a copolymer of 3-hydroxybutyrate units and other hydroxyalkanoate units.

[0020] Specific examples of poly(3-hydroxyalkanoate) resins include poly(3-hydroxybutyrate), poly(3-hydroxybutyrate-co-3-hydroxypropionate), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (abbreviation: P3HB3HV), poly(3-hydroxybutyrate-co-3-hydroxyvalerate-3-hydroxyhexanoate), and poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (abbreviation: P3HB3HH). , poly(3-hydroxybutyrate-co-3-hydroxyheptanoate), poly(3-hydroxybutyrate-co-3-hydroxyoctanoate), poly(3-hydroxybutyrate-co-3-hydroxynonanoate), poly(3-hydroxybutyrate-co-3-hydroxydecanoate), poly(3-hydroxybutyrate-co-3-hydroxyundecanoate), poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (abbreviation: P3HB4HB), etc. In particular, from the viewpoints of productivity and mechanical properties of molded articles, poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) or poly(3-hydroxybutyrate-co-4-hydroxybutyrate) is preferred, and poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) is more preferred.

[0021] In this embodiment, at least two types of poly(3-hydroxyalkanoate) resins having different weight-average molecular weights are used in combination as the poly(3-hydroxyalkanoate) resin (A) from the viewpoints of fluidity during melt processing, improving the strength of the molded body, and suppressing deformation and cracking under heat.

[0022] Specifically, the poly(3-hydroxyalkanoate) resin (A) contains at least the following two types of copolymers: a copolymer (A1) of 3-hydroxybutyrate units and other hydroxyalkanoate units, in which the content of other hydroxyalkanoate units in the total of 3-hydroxybutyrate units and other hydroxyalkanoate units is 5 mol % or more but less than 24 mol %, and the weight-average molecular weight is less than 700,000; and a copolymer (A4) of 3-hydroxybutyrate units and other hydroxyalkanoate units, in which the content of other hydroxyalkanoate units in the total of 3-hydroxybutyrate units and other hydroxyalkanoate units is 5 mol % or more but less than 24 mol %, and the weight-average molecular weight is 700,000 or more.

[0023] In copolymers of 3-hydroxybutyrate units and other hydroxyalkanoate units, the crystallinity generally tends to decrease as the content of other hydroxyalkanoate units increases. Both of the above-mentioned copolymers (A1) and (A4) have moderate crystallinity because the content of other hydroxyalkanoate units is 5 mol% or more and less than 24 mol%. By using a copolymer (A1) with a relatively low molecular weight and a copolymer (A4) with a relatively high molecular weight in combination as a copolymer with moderate crystallinity, it is possible to achieve improved strength of molded articles and suppression of deformation and cracking under heating while ensuring fluidity during melt processing.

[0024] The weight-average molecular weight of the copolymer (A1) is less than 700,000. By using such a copolymer with a relatively low molecular weight, fluidity during melt processing can be ensured. The molecular weight is more preferably 600,000 or less, and even more preferably 500,000 or less. The lower limit is not particularly limited, but from the viewpoint of the strength of the molded product, it is preferably 200,000 or more, and more preferably 300,000 or more.

[0025] In the copolymer (A1), the content of the other hydroxyalkanoate units in the total of the 3-hydroxybutyrate units and the other hydroxyalkanoate units is 5 mol % or more and less than 24 mol %, preferably 5 to 20 mol %, more preferably 5 to 15 mol %, even more preferably 5 to 10 mol %, and particularly preferably 5 to 7 mol %.

[0026] As the copolymer (A1), the copolymers described above can be used, but poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) or poly(3-hydroxybutyrate-co-4-hydroxybutyrate) is preferred, and poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) is particularly preferred.

[0027] In this embodiment, the content of copolymer (A1) in the total amount of poly(3-hydroxyalkanoate) resin (A) and aliphatic aromatic polyester resin (B) is set to a range of 25% by weight or more and 65% by weight or less. By setting the content of copolymer (A1) to 25% by weight or more, fluidity during melt processing can be ensured. Furthermore, by setting the content to 65% by weight or less, improved strength of the molded body and suppression of deformation and cracking under heating can be achieved. The lower limit of the content is preferably 30% by weight or more, more preferably 35% by weight or more, and even more preferably 40% by weight or more. Furthermore, the upper limit of the content is preferably 60% by weight or less.

[0028] On the other hand, the weight average molecular weight of copolymer (A4) is 700,000 or more. By using such a copolymer with a relatively high molecular weight in combination with the aliphatic aromatic polyester resin (B) described later, it is possible to improve the strength of the molded body and suppress deformation and cracking under heating. The molecular weight is preferably 750,000 or more, more preferably 800,000 or more, even more preferably 900,000 or more, and particularly preferably 1,000,000 or more. The upper limit is not particularly limited, but from the viewpoint of productivity, it is preferably 2,500,000 or less, more preferably 2,000,000 or less, and even more preferably 1,500,000 or less.

[0029] The difference in weight-average molecular weight between the copolymer (A1) and the copolymer (A4) is not particularly limited, but is preferably 100,000 or more, more preferably 200,000 or more, and particularly preferably 300,000 or more, in order to more easily exhibit the respective effects of (A1) and (A4).

[0030] In the copolymer (A4), the content of the other hydroxyalkanoate units in the total of the 3-hydroxybutyrate units and the other hydroxyalkanoate units is 5 mol % or more and less than 24 mol %, preferably 5 to 20 mol %, more preferably 6 to 18 mol %, even more preferably 7 to 15 mol %, and particularly preferably 8 to 13 mol %.

[0031] As the copolymer (A4), the copolymers described above can be used, but poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) or poly(3-hydroxybutyrate-co-4-hydroxybutyrate) is preferred, and poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) is particularly preferred.

[0032] In this embodiment, the content of copolymer (A4) in the total amount of poly(3-hydroxyalkanoate) resin (A) and aliphatic aromatic polyester resin (B) is set to a range of 5% by weight or more and 30% by weight or less. By setting the content of copolymer (A4) to 5% by weight or more, it is possible to improve the strength of the molded body and suppress deformation and cracking under heat. Furthermore, by setting the content to 30% by weight or less, it is possible to ensure fluidity during melt processing. The upper limit of the content is preferably 25% by weight or less, and more preferably 20% by weight or less.

[0033] The poly(3-hydroxyalkanoate) resin (A) may be composed only of the copolymers (A1) and (A4). However, from the viewpoint of improving the elongation of the molded article and achieving a good balance between strength and toughness, it is preferable that the poly(3-hydroxyalkanoate) resin (A) further contains a poly(3-hydroxyalkanoate) resin having a different content ratio of constituent monomers from that of (A1) and (A4).

[0034] Specifically, the poly(3-hydroxyalkanoate) resin (A) preferably further contains the following two types of copolymers: (A2) a copolymer of 3-hydroxybutyrate units and other hydroxyalkanoate units, in which the content of the other hydroxyalkanoate units in the total of the 3-hydroxybutyrate units and the other hydroxyalkanoate units is 1 mol % or more and less than 5 mol %, and (A3) a copolymer of 3-hydroxybutyrate units and other hydroxyalkanoate units, in which the content of the other hydroxyalkanoate units in the total of the 3-hydroxybutyrate units and the other hydroxyalkanoate units is 24 mol % or more.

[0035] Copolymer (A2) is a highly crystalline poly(3-hydroxyalkanoate) resin due to its low content of other hydroxyalkanoate units, whereas copolymer (A3) is a low-crystalline poly(3-hydroxyalkanoate) resin. Highly crystalline poly(3-hydroxyalkanoate) resins have good strength but low toughness, while low-crystalline poly(3-hydroxyalkanoate) resins have good toughness but insufficient strength.

[0036] By using these copolymers (A2) and (A3) in combination with copolymers (A1) and (A4), it is possible to improve the strength of a molded article, suppress deformation and cracking under heating, and also improve elongation, thereby obtaining a molded article with a good balance between strength and toughness. A general characteristic of poly(3-hydroxyalkanoate) resins is that as elongation improves, strength tends to decrease. However, according to this embodiment, even if elongation is improved, strength can be maintained without a significant decrease.

[0037] In the copolymer (A2), the content of the other hydroxyalkanoate units in the total of the 3-hydroxybutyrate units and the other hydroxyalkanoate units is 1 mol% or more and less than 5 mol%. From the viewpoint of the balance between strength and toughness and productivity, the lower limit of this ratio is preferably 2 mol% or more. The upper limit may be 4 mol% or less.

[0038] As the copolymer (A2), the copolymers described above can be used, but poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) or poly(3-hydroxybutyrate-co-4-hydroxybutyrate) is preferred, and poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) is more preferred.

[0039] In copolymer (A3), the content of other hydroxyalkanoate units in the total of 3-hydroxybutyrate units and other hydroxyalkanoate units is 24 mol% or more. From the viewpoint of the balance between strength and toughness, the lower limit of this ratio is preferably 26 mol% or more, more preferably 28 mol% or more. Furthermore, from the viewpoint of the productivity of copolymer (A3), the upper limit of this ratio is preferably 99 mol% or less, more preferably 50 mol% or less, even more preferably 40 mol% or less, and particularly preferably 30 mol% or less.

[0040] As the copolymer (A3), the copolymers described above can be used, but poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) or poly(3-hydroxybutyrate-co-4-hydroxybutyrate) is preferred, and poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) is more preferred.

[0041] The weight-average molecular weights of the copolymers (A2) and (A3) are not particularly limited and may be appropriately set taking into consideration the weight-average molecular weight of the entire poly(3-hydroxyalkanoate) resin (A), but from the viewpoint of achieving both the mechanical properties and productivity of the molded article, they are preferably from 200,000 to 2,000,000, more preferably from 250,000 to 1,500,000, and particularly preferably from 300,000 to 1,000,000. In order to more easily realize the effects of using the copolymer (A4) described above, it is preferable that the weight-average molecular weights of the copolymers (A2) and (A3) are each less than 700,000.

[0042] In this embodiment, the total content of copolymers (A2) and (A3) in the total amount of poly(3-hydroxyalkanoate) resin (A) and aliphatic aromatic polyester resin (B) can be set as appropriate. However, from the viewpoint of improving the elongation of the molded body and achieving a good balance between strength and toughness, it is preferably set in the range of 15% by weight or more and 55% by weight or less. By setting this total content to 15% by weight or more, the toughness of the molded body can be improved. Furthermore, by setting this total content to 55% by weight or less, the strength of the molded body can be improved. The lower limit of the total content is preferably 20% by weight or more, more preferably 25% by weight or more. Furthermore, the upper limit of the total content is preferably 50% by weight or less, more preferably 45% by weight or less, and even more preferably 40% by weight or less.

[0043] The proportion of copolymer (A2) and copolymer (A3) used is not particularly limited, but from the viewpoint of the balance between strength and toughness and productivity, the proportion of copolymer (A2) in the total amount of copolymer (A2) and copolymer (A3) is preferably 35% by weight or more and the proportion of copolymer (A3) is 65% by weight or less, more preferably 40% by weight or more and the proportion of copolymer (A3) is 60% by weight or less. Also, the proportion of copolymer (A2) is preferably 75% by weight or less and the proportion of copolymer (A3) is 25% by weight or more, more preferably 65% ​​by weight or less and the proportion of copolymer (A3) is 35% by weight or more.

[0044] From the viewpoint of achieving both mechanical properties and productivity of a molded article, the average content ratio of 3-hydroxybutyrate units and other hydroxyalkanoate units in all monomer units constituting the poly(3-hydroxyalkanoate) resin (A) is preferably 3-hydroxybutyrate units / other hydroxyalkanoate units=98 / 2 to 65 / 35 (mol % / mol %), more preferably 96 / 4 to 75 / 25 (mol % / mol %), even more preferably 95 / 5 to 80 / 20 (mol % / mol %), and particularly preferably 96 / 6 to 85 / 15 (mol % / mol %).

[0045] The average content ratio of each monomer unit in all monomer units constituting the poly(3-hydroxyalkanoate) resin (A) or each copolymer can be determined by a method known to those skilled in the art, for example, the method described in paragraph

[0047] of WO 2013 / 147139. The average content ratio of each monomer unit in the poly(3-hydroxyalkanoate) resin (A) means the molar proportion of each monomer unit in all monomer units in the entire poly(3-hydroxyalkanoate) resin (A), and refers to the molar proportion of each monomer unit contained in the entire mixture of multiple poly(3-hydroxyalkanoate) resins constituting the poly(3-hydroxyalkanoate) resin (A).

[0046] The weight average molecular weight of the entire poly(3-hydroxyalkanoate) resin (A) is not particularly limited, but from the viewpoint of achieving both mechanical properties and productivity of the molded article, it is preferably from 50,000 to 3,000,000, more preferably from 200,000 to 2,000,000, even more preferably from 250,000 to 1,500,000, and particularly preferably from 300,000 to 800,000.

[0047] The weight-average molecular weight of the poly(3-hydroxyalkanoate) resin (A) or each copolymer can be measured in terms of polystyrene using gel permeation chromatography (HPLC GPC system manufactured by Shimadzu Corporation) using a chloroform solution. As a column for the gel permeation chromatography, a column appropriate for measuring the weight-average molecular weight may be used.

[0048] The poly(3-hydroxyalkanoate) resin (A) or each copolymer is preferably not crosslinked using a crosslinking agent such as an organic peroxide, that is, it is preferable that it does not have a crosslinked structure.

[0049] The method for producing poly(3-hydroxyalkanoate) resins is not particularly limited, and may be a production method using chemical synthesis or a production method using a microorganism. Among these, a production method using a microorganism is preferred. Known methods can be applied to the production method using a microorganism. For example, known bacteria that produce copolymers of 3-hydroxybutyrate and other hydroxyalkanoates include Aeromonas caviae, which produces P3HB3HV and P3HB3HH, and Alcaligenes eutrophus, which produces P3HB4HB. In particular, with regard to P3HB3HH, in order to increase the productivity of P3HB3HH, Alcaligenes eutrophus AC32 strain (FERM BP-6038) (T. Fukui, Y. Doi, J. Bateriol., 179, pp. 4821-4830 (1997)) or the like into which genes encoding P3HA synthases have been introduced is more preferred, and microbial cells obtained by culturing these microorganisms under appropriate conditions and allowing P3HB3HH to accumulate within the cells are used. In addition to the above, genetically modified microorganisms into which various poly(3-hydroxyalkanoate) resin synthesis-related genes have been introduced may be used depending on the poly(3-hydroxyalkanoate) resin to be produced, or the culture conditions, including the type of substrate, may be optimized.

[0050] (Aliphatic Aromatic Polyester Resin (B)) The resin composition according to this embodiment contains an aliphatic aromatic polyester resin (B) in addition to the poly(3-hydroxyalkanoate) resin (A). By using the aliphatic aromatic polyester resin (B) in combination with the high molecular weight copolymer (A4), it is possible to improve the strength of the molded article and suppress deformation and cracking under heat.

[0051] The aliphatic-aromatic polyester resin is a polyester resin that is composed of one or more dicarboxylic acid units selected from the group consisting of aliphatic dicarboxylic acid units and aromatic dicarboxylic acid units, and one or more diol units selected from the group consisting of aliphatic diol units and aromatic diol units, and has both aliphatic units and aromatic units.

[0052] Examples of the aliphatic aromatic polyester resin include polybutylene adipate terephthalate resin, polybutylene sebacate terephthalate resin, polybutylene succinate terephthalate resin, etc. Polybutylene adipate terephthalate resin (PBAT) is particularly preferred.

[0053] Polybutylene adipate terephthalate (PBAT) resin refers to a random copolymer of 1,4-butanediol, adipic acid, and terephthalic acid. Of these, PBAT obtained by reacting (a) a mixture consisting primarily of 35 to 95 mol % of adipic acid or its ester-forming derivative, or a mixture thereof, and 5 to 65 mol % of terephthalic acid or its ester-forming derivative, or a mixture thereof (the sum of the individual mol % is 100 mol %) with (b) a mixture containing butanediol (provided that the molar ratio of (a) to (b) is 0.4:1 to 1.5:1), as described in JP-A-10-508640, etc., is preferred. Commercially available PBAT products include "Ecoflex" (registered trademark) manufactured by BASF.

[0054] In this embodiment, the content of the aliphatic aromatic polyester resin (B) in the total amount of the poly(3-hydroxyalkanoate) resin (A) and the aliphatic aromatic polyester resin (B) is set to a range of 5% by weight or more and 30% by weight or less. By setting the content of the aliphatic aromatic polyester resin (B) to 5% by weight or more and 30% by weight or less, it is possible to improve the strength of the molded body and suppress deformation and cracking under heat. The lower limit of the content is preferably 8% by weight or more, and more preferably 10% by weight or more. The upper limit of the content is preferably 25% by weight or less, and more preferably 20% by weight or less.

[0055] (Other Resins) The resin composition according to this embodiment may contain polyester resins other than the poly(3-hydroxyalkanoate) resin (A) and the aliphatic aromatic polyester resin (B), as long as the effects of the invention are not impaired. Examples of such other polyester resins include aliphatic polyester resins such as polybutylene succinate adipate, polybutylene succinate, polycaprolactone, and polylactic acid. Only one type of other polyester resin may be contained, or two or more types may be contained.

[0056] The content of the other polyester resin is not particularly limited, but is preferably 30 parts by weight or less, more preferably 20 parts by weight or less, even more preferably 10 parts by weight or less, and particularly preferably 5 parts by weight or less, relative to 100 parts by weight of the total amount of the poly(3-hydroxyalkanoate) resin (A) and the aliphatic aromatic polyester resin (B). It may even be 1 part by weight or less. The lower limit of the content of the other polyester resin is not particularly limited, and may even be 0 parts by weight.

[0057] The resin composition according to the present embodiment may contain a resin other than a polyester-based resin, but preferably contains a polyester-based resin as the main resin component. The proportion of the polyester-based resin in the total resin components contained in the resin composition according to the present embodiment is preferably 50 to 100 wt %, more preferably 70 to 100 wt %, even more preferably 80 to 100 wt %, and still more preferably 90 to 100 wt %.

[0058] (Additives) The resin composition according to this embodiment may contain additives as long as the effects of the invention are not impaired. Examples of additives that can be used depending on the purpose include crystallization nucleating agents, lubricants, plasticizers, antistatic agents, flame retardants, conductive agents, heat insulating agents, crosslinking agents, antioxidants, UV absorbers, colorants, inorganic fillers, organic fillers, and hydrolysis inhibitors. Biodegradable additives are particularly preferred.

[0059] As the inorganic filler, a mineral containing layered silicate as a main component can be preferably used, for example, in that it can provide effects such as improved heat resistance and improved processability.

[0060] In particular, the inorganic filler is preferably one or more selected from the group consisting of smectite, mica, talc, pyroferrite, vermiculite, chlorite, kaolinite, and serpentine, in terms of ease of obtaining an effect of improving processability. From the viewpoint of versatility, mica, talc, and kaolinite are preferred, and talc is particularly preferred.

[0061] Examples of the mica include wet-ground mica and dry-ground mica, and specific examples include mica manufactured by Yamaguchi Mica Co., Ltd. and Keiwa Rozai Co., Ltd.

[0062] Examples of the talc include general-purpose talc and surface-treated talc. Specific examples include "Microace" (registered trademark) from Nippon Talc Co., Ltd., "Talc Powder" (registered trademark) from Hayashi Kasei Co., Ltd., and talc manufactured by Takehara Chemical Industry Co., Ltd. and Maruo Calcium Co., Ltd.

[0063] Examples of the kaolinite include dry kaolin, calcined kaolin, and wet kaolin. Specific examples include "TRANSLINK" (registered trademark), "ASP" (registered trademark), "SANTINTONE" (registered trademark), and "ULTREX" (registered trademark) manufactured by Hayashi Kasei Co., Ltd., and kaolinite manufactured by Keiwa Rozai Co., Ltd.

[0064] When the inorganic filler is used, its content is preferably 5 parts by weight or more and 30 parts by weight or less, relative to 100 parts by weight of the total amount of the poly(3-hydroxyalkanoate) resin (A) and the aliphatic aromatic polyester resin (B). When the inorganic filler content is 5 parts by weight or more, the solidification properties of the resin tend to be improved, and moldability tends to be good. When the inorganic filler content is 30 parts by weight or less, the resin composition tends to have an appropriate melt viscosity, and moldability tends to be good. The lower limit of the content is preferably 7 parts by weight or more, and more preferably 10 parts by weight or more. The upper limit of the content is preferably 27 parts by weight or less, more preferably 25 parts by weight or less, and even more preferably 20 parts by weight or less.

[0065] Examples of crystallization nucleating agents include pentaerythritol, orotic acid, aspartame, cyanuric acid, glycine, zinc phenylphosphonate, and boron nitride. Among these, pentaerythritol is preferred because it is particularly effective in promoting the crystallization of the polyester resin component. The amount of crystallization nucleating agent used is not particularly limited, but is preferably 0.1 to 5 parts by weight, more preferably 0.5 to 3 parts by weight, and even more preferably 0.7 to 1.5 parts by weight, per 100 parts by weight of the total amount of the polyester resin component. Furthermore, one type of crystallization nucleating agent may be used, or two or more types may be used, and the usage ratio can be appropriately adjusted depending on the purpose.

[0066] Examples of lubricants include behenamide, oleamide, erucamide, stearamide, palmitamide, N-stearylbehenamide, N-stearylerucamide, ethylenebisstearamide, ethylenebisoleamide, ethylenebiserucamide, ethylenebislauricamide, ethylenebiscapricamide, p-phenylenebisstearamide, and polycondensates of ethylenediamine, stearic acid, and sebacic acid. Among these, behenamide or erucamide are preferred because of their particularly excellent lubricating effect on polyester-based resin components. The amount of lubricant used is not particularly limited, but is preferably 0.01 to 5 parts by weight, more preferably 0.05 to 3 parts by weight, and even more preferably 0.1 to 1.5 parts by weight, per 100 parts by weight of the total amount of polyester-based resin components. Furthermore, one type of lubricant may be used, or two or more types may be used, and the usage ratio can be appropriately adjusted depending on the purpose.

[0067] Examples of plasticizers include glycerin ester compounds, citrate ester compounds, sebacate compounds, adipate compounds, polyether ester compounds, benzoate ester compounds, phthalate ester compounds, isosorbide ester compounds, polycaprolactone compounds, and dibasic acid ester compounds. Among these, glycerin ester compounds, citrate ester compounds, sebacate compounds, and dibasic acid ester compounds are preferred because of their particularly excellent plasticizing effect on polyester resin components. Examples of glycerin ester compounds include glycerin diacetomonolaurate. Examples of citrate ester compounds include acetyl tributyl citrate. Examples of sebacate ester compounds include dibutyl sebacate. Examples of dibasic acid ester compounds include benzyl methyl diethylene glycol adipate. The amount of plasticizer used is not particularly limited, but is preferably 1 to 20 parts by weight, more preferably 2 to 15 parts by weight, and even more preferably 3 to 10 parts by weight, relative to 100 parts by weight of the polyester resin component. One type of plasticizer may be used, or two or more types may be used, and the usage ratio can be appropriately adjusted depending on the purpose.

[0068] The resin composition according to the present embodiment preferably exhibits good fluidity during melt processing. From this viewpoint, the resin composition preferably has a melt flow rate measured at 165°C of 3 to 10 g / 10 min, more preferably 4 to 8 g / 10 min. The melt flow rate can be measured by the method described in the Examples section.

[0069] The resin composition according to this embodiment has high strength, and can therefore be used to suitably produce molded articles with good usability. The fracture energy based on ISO 178-A can be used as an indicator of good usability. Specifically, the resin composition according to this embodiment preferably exhibits a fracture energy of 0.50 J or more, and more preferably 0.76 J or more. The fracture energy of acrylonitrile / butadiene / styrene resin (ABS), a general-purpose resin known for its high strength, is 0.76 J. The fracture energy value is more preferably 0.8 J or more, even more preferably 0.9 J or more, and particularly preferably 1.0 J or more. The fracture energy can be measured by the method described in the Examples section.

[0070] The resin composition according to this embodiment has high toughness, which makes it possible to avoid deformation or cracking during use of the molded article. The elongation at break based on ISO 527-1 and ISO 527-2 can be used as an index of high toughness. Specifically, the resin composition according to this embodiment preferably has an elongation at break of 80% or more, more preferably 90% or more, and even more preferably 100% or more. The upper limit of the elongation at break is not particularly limited, but may be, for example, 300% or less, or 200% or less. The elongation at break can be measured by the method described in the Examples section.

[0071] (Method for producing resin composition) The resin composition according to this embodiment can be produced by melt-kneading each component. After melt-kneading, pelletization may be performed, or a molded product other than pellets may be produced directly without pelletization. The method will be described in detail below.

[0072] First, a polyester resin component and any additives are added and melt-kneaded using an extruder, kneader, Banbury mixer, roll, or the like to prepare a resin composition. The resin composition may be extruded into a strand shape and then cut to obtain pellets having a particle shape such as a cylindrical, elliptical cylindrical, spherical, cubic, or rectangular parallelepiped shape. The prepared pellets are desirably thoroughly dried at 40 to 80°C to remove moisture before being subjected to the next molding step.

[0073] The temperature at which the melt-kneading is carried out cannot be generally defined because it depends on the melting point, melt viscosity, etc. of the resin used, but the resin temperature at the die outlet of the melt-kneaded product is preferably 135 to 200° C., more preferably 140 to 195° C., even more preferably 145 to 190° C., and particularly preferably 150 to 185° C. If the resin temperature of the melt-kneaded product is 135° C. or higher, the polyester-based resin component can be uniformly melted, and if it is 200° C. or lower, thermal decomposition of the polyester-based resin component can be avoided.

[0074] The resin composition according to the present embodiment can be used to produce a molded article through a molding process after melt-kneading. The molding method is not particularly limited, but examples thereof include injection molding, extrusion molding, blow molding, and calendar molding. In particular, injection molding is preferably used.

[0075] Specific examples of molded articles, particularly injection molded articles, that can be formed from the resin composition according to this embodiment include capsules for extracting beverages such as coffee capsules, three-dimensional toys, cutlery, cups, and the like.

[0076] The beverage extraction capsule is a type of container for storing beverage substances such as coffee or tea leaves, and is a container in which the beverage substance is filled into the capsule cavity.When extracting the beverage, the beverage is extracted by injecting pressurized hot water into the capsule, and this capsule is disclosed, for example, in European Patent No. 1792850.

[0077] The resin composition according to the present embodiment is suppressed from deforming and cracking under heat, and therefore can be suitably used to form the beverage extraction capsule. The beverage extraction capsule made from the resin composition according to the present embodiment is less likely to deform or crack during beverage extraction, and therefore can exhibit good beverage extraction properties without the beverage substance leaking out.

[0078] The capsule for extracting beverages can be produced by molding the resin composition by a known molding method, particularly injection molding.

[0079] Injection molding is a method in which a heated and melted resin composition is injected into a mold, the resin composition is cooled and solidified in the mold, the mold is opened, and the molded article is demolded to obtain a molded article. Injection molding methods that can be used include injection molding methods commonly used when molding thermoplastic resins, as well as injection blow molding, gas-assisted molding, injection compression molding, and other injection molding methods. In-mold molding, gas press molding, two-color molding, sandwich molding, push-pull molding, SCORIM molding, and the like can also be used. However, the injection molding methods that can be used are not limited to the above methods.

[0080] The temperature at which the resin is cooled in the mold after injection can be determined as appropriate by a person skilled in the art, but is preferably 20 to 70°C, more preferably 25 to 60°C, even more preferably 30 to 50°C, and particularly preferably 35 to 45°C.

[0081] The resin composition or molded article according to this embodiment has a poly(3-hydroxyalkanoate) resin as its main component and therefore has good seawater degradability, and therefore can solve the environmental problems caused by dumping plastics into the ocean.

[0082] The following items list preferred aspects of the present disclosure, but the present invention is not limited to the following items. [Item 1] A resin composition containing a polyester resin component, wherein the polyester resin component comprises a poly(3-hydroxyalkanoate) resin (A) and an aliphatic aromatic polyester resin (B), wherein the poly(3-hydroxyalkanoate) resin (A) comprises a copolymer (A1) of 3-hydroxybutyrate units and other hydroxyalkanoate units, in which the content of the other hydroxyalkanoate units in the total of the 3-hydroxybutyrate units and the other hydroxyalkanoate units is 5 mol% or more and less than 24 mol%, and the weight-average molecular weight is less than 700,000, and a copolymer (A4) of 3-hydroxybutyrate units and other hydroxyalkanoate units, in which the content of the other hydroxyalkanoate units in the total of the 3-hydroxybutyrate units and the other hydroxyalkanoate units is 5 mol% or more and less than 24 mol%, and the weight-average molecular weight is 700,000 or more, A resin composition, wherein the content of the copolymer (A1) is 25% by weight or more and 65% by weight or less, the content of the copolymer (A4) is 5% by weight or more and 30% by weight or less, and the content of the aliphatic aromatic polyester resin (B) is 5% by weight or more and 30% by weight or less, relative to the total amount of the poly(3-hydroxyalkanoate) resin (A) and the aliphatic aromatic polyester resin (B). [Item 2] The resin composition according to Item 1, wherein the melt flow rate at 165°C of the resin composition is 3 to 10 g / 10 min.[Item 3] The resin composition according to Item 1 or 2, wherein the poly(3-hydroxyalkanoate) resin (A) further comprises: a copolymer (A2) of 3-hydroxybutyrate units and other hydroxyalkanoate units, in which the content of the other hydroxyalkanoate units is 1 mol % or more and less than 5 mol % of the total of the 3-hydroxybutyrate units and the other hydroxyalkanoate units; and a copolymer (A3) of 3-hydroxybutyrate units and other hydroxyalkanoate units, in which the content of the other hydroxyalkanoate units is 24 mol % or more of the total of the 3-hydroxybutyrate units and the other hydroxyalkanoate units; and the total content of the copolymer (A2) and the copolymer (A3) is 15 wt % or more and 55 wt % or less of the total amount of the poly(3-hydroxyalkanoate) resin (A) and the aliphatic aromatic polyester resin (B). [Item 4] The resin composition according to Item 3, wherein, of the total amount of the copolymer (A2) and the copolymer (A3), a proportion of the copolymer (A2) is 35% by weight or more and a proportion of the copolymer (A3) is 65% by weight or less. [Item 5] The resin composition according to any one of Items 1 to 4, wherein the weight-average molecular weight of the copolymer (A4) is 1,000,000 or more. [Item 6] The resin composition according to any one of Items 1 to 5, wherein the aliphatic aromatic polyester-based resin (B) is at least one selected from the group consisting of polybutylene adipate terephthalate-based resins, polybutylene sebacate terephthalate-based resins, and polybutylene succinate terephthalate-based resins. [Item 7] A molded article comprising the resin composition according to any one of Items 1 to 6. [Item 8] The molded article according to Item 7, wherein the molded article is an injection-molded article.

[0083] The present invention will be specifically explained below with reference to examples, but the technical scope of the present invention is not limited to these examples.

[0084] The following raw materials were used in each example and comparative example. [Polyester-based resin] Copolymer (A1): P3HB3HH-1 [poly(3-hydroxybutyrate-3-hydroxyhexanoate), average content ratio 3HB / 3HH = 94.6 / 5.4 (mol% / mol%), weight-average molecular weight 360,000 g / mol] Copolymer (A2): P3HB3HH-2 [poly(3-hydroxybutyrate-3-hydroxyhexanoate), average content ratio 3HB / 3HH = 97.2 / 2.8 (mol% / mol%), weight-average molecular weight 660,000 g / mol] Produced in accordance with the method described in Example 2 of International Publication WO2019 / 142845. Copolymer (A3): P3HB3HH-3 [poly(3-hydroxybutyrate-3-hydroxyhexanoate), average content ratio 3HB / 3HH=71.8 / 28.2 (mol% / mol%), weight average molecular weight 660,000 g / mol] was produced in accordance with the method described in Example 9 of International Publication WO2019 / 142845. Copolymer (A4-1): P3HB3HH-4 [poly(3-hydroxybutyrate-3-hydroxyhexanoate), average content ratio 3HB / 3HH = 89.5 / 10.5 (mol% / mol%), weight average molecular weight: 800,000 g / mol] Copolymer (A4-2): P3HB3HH-4 [poly(3-hydroxybutyrate-3-hydroxyhexanoate), average content ratio 3HB / 3HH = 89.5 / 10.5 (mol% / mol%), weight average molecular weight: 1.2 million g / mol] Aliphatic aromatic polyester resin (B): polybutylene adipate terephthalate (PBAT) [product name: Ecoflex (registered trademark), grade: FBlend C1200, manufactured by BASF]

[0085] [Additives] Additive-1: Behenic acid amide (manufactured by Nippon Fine Chemical Co., Ltd.: BNT-22H) Additive-2: Pentaerythritol [manufactured by Mitsubishi Chemical Corporation: Neuraizer P]

[0086] The evaluation methods used in the examples and comparative examples are described below. (Preparation of molding blend) 50 g (0.5 parts by weight) of additive-1 and 100 g (1 part by weight) of additive-2 were added to a total weight of 9 kg (90% by weight) of the components (A1), (A2), (A3), and (A4) in the blending ratios shown in Table 2 using a 75L Super Mixer manufactured by Kawata Co., Ltd., and stirred at 300 rpm for 3 minutes to obtain a molding blend.

[0087] (Compounding) A Toshiba Machine TEM26SS (L / D = 60) was used, with the screw configuration, auxiliary equipment, and barrel temperature settings listed in Table 1, and the screw rotation speed was set to 100 rpm. The molding blend was supplied from the base of the screw via main feed 1 at a rate of 9.01 kg / hr, and simultaneously, 1 kg (10 wt%) of component (B) was supplied from the base of the screw via main feed 2 at a rate of 0.99 kg / hr. However, the total weight of components (A1) to (A4) and the weight of component (B) were appropriately adjusted according to the blending ratios listed in Table 2. The strand emerging from the die tip was passed through a water tank filled with warm water at 40°C to 45°C to solidify, and then cut using a pelletizer to obtain a pelletized compound.

[0088]

[0089] [Sample Preparation and Various Evaluations] <Method for Measuring Weight-Average Molecular Weight of Components (A1) to (A4)> The weight-average molecular weight of components (A1) to (A4) was measured by first dissolving the resin to be measured in chloroform and heating it in a hot water bath at 60°C for 0.5 hours, filtering the soluble matter through a disposable PTFE filter with a 0.2 μm pore size, and then using the filtrate to perform GPC measurement under the following conditions: GPC measurement device: Nexera manufactured by Shimadzu Corporation Column: TSKGelGMH manufactured by Tosoh Corporation ＸＬ (2 pieces), TSKGuard column H ＸＬ (1 tube) Sample concentration: 3 mg / ml Free solution: chloroform solution Free solution flow rate: 1.0 ml / min Sample injection volume: 100 μL Analysis time: 30 min Standard sample: standard polystyrene

[0090] <Measurement of Melt Flow Rate (MFR) of Resin Composition> Based on ISO 1133-1, 5 g or more of the pellet-shaped compound was heated at 165° C. for 4 minutes using a melt indexer, and then the melt flow rate (MFR) was measured under a load of 5 kg.

[0091] <Preparation of Dumbbell Test Pieces> Using a dumbbell mold of 168 mm × 20 mm × 4 mm thick, a Toyo Machinery Metal injection molding machine Si-100V was used, with nozzle / T1 / T2 / T3 / T4 = 150 / 150 / 150 / 150 / 150°C and mold temperature set to 35°C, to obtain dumbbell test pieces (168 mm × 20 mm × 4 mm thick).

[0092] <Measurement of tensile modulus, elongation at break and energy at break> After leaving the dumbbell test pieces at 23°C for 30 days, a tensile test was carried out at 20 mm / min in accordance with ISO 527-1 and ISO 527-2 to measure the tensile modulus, elongation at break and energy at break.

[0093] <Measurement of Fracture Energy> After leaving the dumbbell test specimens at 23°C for 30 days, a 2 mm vertical V-notch was made in the center of the dumbbell test specimens, and a bending test was carried out at 100 mm / min in accordance with ISO 178-A, to obtain a graph of test force versus displacement as shown in Figure 1. The fracture energy was measured from the area of ​​the shaded portion under the curve in the obtained graph. Note that the fracture energy measured in the same manner for acrylonitrile / butadiene / styrene resin (ABS), a general-purpose resin known to have high strength, was 0.76 J.

[0094] <Measurement of deflection temperature under load> After leaving the dumbbell test specimens at 23°C for 30 days, a deflection temperature under load test was carried out at 0.45 MPa in accordance with ISO 751-1 and ISO 751-2 to measure the deflection temperature under load. A higher deflection temperature under load indicates better heat resistance.

[0095] <Preparation of beverage extraction capsules> A four-cavity coffee capsule mold with a pin gate and hot runner was used, and a Toyo Machinery Metal injection molding machine Si-100V was used, with nozzle / T1 / T2 / T3 = 160 / 160 / 160 / 160°C and the mold temperature set to 40°C, to obtain beverage extraction capsules (thickness 0.45 mm).

[0096] <Evaluation of deformation and cracking during beverage extraction> The obtained beverage extraction capsules were filled with Espresso-grade finely ground coffee powder and closed with aluminum lids designed specifically for capsules. Coffee was then extracted using a coffee machine, and the capsules were evaluated for deformation and cracking during coffee extraction based on the following criteria: (Deformation) ◯: The capsule was not deformed. ×: The capsule was deformed. (Cracking) ◯: No cracks occurred throughout the capsule. ×: Cracks occurred in the capsule.

[0097] <Pressure resistance test> The coffee extraction hole of the beverage extraction capsule obtained as an evaluation sample was sealed with a polyimide film and adhesive, the capsule was covered with a metal plate with an air inlet, the air inlet was connected to a compressor, and high-pressure air was applied in an environment of 85°C to measure the pressure at which the evaluation sample broke. Measurements were carried out for Examples 3 and 6, and Comparative Example 1.

[0098]

[0099] Table 2 shows that the resin compositions of Examples 1 to 6 exhibited higher fracture energies than Comparative Example 1, the resin compositions of Examples 7 and 8 exhibited higher fracture energies than Comparative Example 2, and the resin composition of Example 9 exhibited higher fracture energies than Comparative Examples 3 to 5, indicating high strength. In addition, the resin compositions of each Example had a modulus of elasticity of 700 MPa or more and a breaking elongation of 100% or more, indicating a wide range of deformation while maintaining hardness, and a practical balance of strength and toughness. Furthermore, it was found that the capsules for beverage extraction obtained from the resin compositions of Examples 1 to 9 did not deform or crack during beverage extraction, and deformation and cracking during heating were suppressed.

[0100] On the other hand, in Comparative Examples 1 and 2, which did not contain the (A4) component, the capsules deformed during beverage extraction. Furthermore, in Comparative Examples 3 and 4, which did not contain either the (A4) or (B) component, and Comparative Example 5, which did not contain the (B) component, the capsules deformed during beverage extraction and even cracked. The results of these Comparative Examples demonstrate that the combined use of the (A4) component and the (B) component is necessary to suppress deformation and cracking during heating. Furthermore, Comparative Examples 1, 4, and 5 demonstrated low fracture energy and insufficient strength.

Claims

1. A resin composition containing a polyester resin component, the polyester resin component comprising a poly(3-hydroxyalkanoate) resin (A) and an aliphatic aromatic polyester resin (B), the poly(3-hydroxyalkanoate) resin (A) comprising a copolymer (A1) of 3-hydroxybutyrate units and other hydroxyalkanoate units, the content of which in the total of the 3-hydroxybutyrate units and the other hydroxyalkanoate units is 5 mol% or more and less than 24 mol%, and the weight average molecular weight is less than 700,000, and a copolymer (A4) of 3-hydroxybutyrate units and other hydroxyalkanoate units, the content of which in the total of the 3-hydroxybutyrate units and the other hydroxyalkanoate units is 5 mol% or more and less than 24 mol%, and the weight average molecular weight is 700,000 or more, A resin composition, wherein the content of the copolymer (A1) is 25% by weight or more and 65% by weight or less, the content of the copolymer (A4) is 5% by weight or more and 30% by weight or less, and the content of the aliphatic aromatic polyester resin (B) is 5% by weight or more and 30% by weight or less, based on the total amount of the poly(3-hydroxyalkanoate) resin (A) and the aliphatic aromatic polyester resin (B).

2. The resin composition according to claim 1, wherein the melt flow rate of the resin composition at 165°C is 3 to 10 g / 10 min.

3. The resin composition according to claim 1 or 2, wherein the poly(3-hydroxyalkanoate) resin (A) further comprises a copolymer (A2) of 3-hydroxybutyrate units and other hydroxyalkanoate units, in which the content of the other hydroxyalkanoate units in the total of the 3-hydroxybutyrate units and the other hydroxyalkanoate units is 1 mol % or more and less than 5 mol %, and a copolymer (A3) of 3-hydroxybutyrate units and other hydroxyalkanoate units, in which the content of the other hydroxyalkanoate units in the total of the 3-hydroxybutyrate units and the other hydroxyalkanoate units is 24 mol % or more, and the total content of the copolymer (A2) and the copolymer (A3) is 15 wt % or more and 55 wt % or less relative to the total amount of the poly(3-hydroxyalkanoate) resin (A) and the aliphatic aromatic polyester resin (B).

4. A resin composition according to claim 3, wherein the proportion of said copolymer (A2) is 35% by weight or more and the proportion of said copolymer (A3) is 65% by weight or less in the total amount of said copolymer (A2) and said copolymer (A3).

5. The resin composition according to claim 1 or 2, wherein the weight average molecular weight of the copolymer (A4) is 1,000,000 or more.

6. The resin composition according to claim 1 or 2, wherein the aliphatic aromatic polyester resin (B) is at least one selected from the group consisting of polybutylene adipate terephthalate resins, polybutylene sebacate terephthalate resins, and polybutylene succinate terephthalate resins.

7. A molded article comprising the resin composition according to claim 1 or 2.

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

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