Aliphatic polyester resin composition and use thereof

Abstract

A purpose of the present invention is to provide an aliphatic-polyester-based resin composition having biodegradability and excellent impact resistance. The purpose is achieved with an aliphatic-polyester-based resin composition comprising compatibilized biodegradable resins which include (A) a poly(3-hydroxyalkanoate) (P3HA) and (B) a product of reaction among a P3HA, a biodegradable resin that is not a P3HA and has a glass transition temperature of -10°C or lower, and a peroxide, and which has a dispersed-particle diameter of 0.1-1.5 μm.

Description

[Technical Field]

[0001] The present invention relates to an aliphatic polyester resin composition containing poly(3-hydroxyalkanoate) (hereinafter, sometimes referred to as "P3HA" or "P3HA-based resin"), and use thereof. [Background technology]

[0002] In recent years, environmental problems caused by discarded plastics have been attracting attention. In particular, marine pollution caused by discarded plastics is serious, and there are high hopes for the widespread use of biodegradable plastics that decompose in the natural environment.

[0003] Among the various biodegradable plastics known, P3HA is a thermoplastic polyester that is produced and accumulated as an energy storage substance within the cells of many microbial species, and is a material that can biodegrade not only in soil but also in seawater, making it a promising material for solving the above problems. However, P3HA has problems such as poor impact resistance.

[0004] As a technique for solving such problems, for example, Patent Document 1 discloses a resin composition containing a graft polymer in a P3HA-based resin.

[0005] Furthermore, Patent Document 2 discloses a resin composition containing a P3HA-based resin and a biodegradable resin other than the P3HA-based resin, such as polybutylene adipate terephthalate, polybutylene succinate adipate, polybutylene succinate, or polycaprolactone. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 6291472 [Patent Document 2] International Publication No. 2010 / 013483 Summary of the Invention [Problem to be solved by the invention]

[0007] The techniques of Patent Documents 1 and 2 above leave room for improvement in terms of impact resistance.

[0008] Therefore, an object of the present invention is to provide an aliphatic polyester resin composition having biodegradability and excellent impact resistance, a molded article thereof, and a method for producing the aliphatic polyester resin composition. [Means for solving the problem]

[0009] As a result of extensive research to solve the above-mentioned problems, the inventors have discovered for the first time that an aliphatic polyester resin composition having biodegradability and excellent impact resistance can be obtained by first mixing (e.g., melt-kneading) a portion of the P3HA contained in an aliphatic polyester resin composition with a specific biodegradable resin other than P3HA and a peroxide, and then reacting them to obtain a compatibilized biodegradable resin containing the reaction product, and then mixing (e.g., melt-kneading) the obtained compatibilized biodegradable resin with the remaining P3HA, thereby completing the present invention.

[0010] Therefore, one aspect of the present invention is an aliphatic polyester resin composition containing the following (A) and (B): (A) poly(3-hydroxyalkanoate), (B) a compatibilized biodegradable resin containing a reaction product of poly(3-hydroxyalkanoate), a biodegradable resin other than poly(3-hydroxyalkanoate) having a glass transition temperature of -10°C or less, and a peroxide, and the dispersed particle diameter of (B) in the aliphatic polyester resin composition is 0.1 to 1.5 μm.

[0011] Another aspect of the present invention is a method for producing an aliphatic polyester resin composition, comprising: (a) a step of melt-kneading poly(3-hydroxyalkanoate), a biodegradable resin other than poly(3-hydroxyalkanoate) and having a glass transition temperature of −10°C or lower, and a peroxide to obtain a compatibilized biodegradable resin; and (b) a step of melt-kneading the compatibilized biodegradable resin obtained in step (a) with poly(3-hydroxyalkanoate) to obtain an aliphatic polyester resin composition. [Effects of the Invention]

[0012] According to one aspect of the present invention, it is possible to provide an aliphatic polyester resin composition having biodegradability and excellent impact resistance, a molded article thereof, and a method for producing the aliphatic polyester resin composition. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 2 shows images of cross sections of molded bodies (test pieces) in an example ((b) in the figure) and a comparative example ((a) in the figure) observed with a transmission electron microscope. DETAILED DESCRIPTION OF THE INVENTION

[0014] An embodiment of the present invention will be described in detail below. In this specification, unless otherwise specified, "A to B" representing a numerical range means "A or more and B or less." In addition, all documents described in this specification are incorporated herein by reference.

[0015] 1. Overview of the Invention An aliphatic polyester resin composition according to one embodiment of the present invention (hereinafter referred to as "the present aliphatic polyester resin composition") is an aliphatic polyester resin composition containing the following (A) and (B): (A) poly(3-hydroxyalkanoate), (B) a compatibilized biodegradable resin containing a reaction product of poly(3-hydroxyalkanoate), a biodegradable resin other than poly(3-hydroxyalkanoate) having a glass transition temperature of -10°C or less, and a peroxide, and is characterized in that the dispersed particle diameter of (B) in the aliphatic polyester resin composition is 0.1 to 1.5 μm.

[0016] P3HA is known to have several problems, including (1) poor impact resistance, (2) extremely slow crystallization, which reduces processability and productivity during molding, and (3) a tendency to become brittle over time after molding.

[0017] Furthermore, in order to impart flexibility to P3HA, plasticizers have traditionally been added, but in some cases it is necessary to add large amounts of plasticizer, which can cause problems such as the plasticizer bleeding out.

[0018] To address these problems, Patent Document 1 discloses a resin composition containing a graft polymer in a P3HA resin, with the aim of improving the low impact strength and molding processability.

[0019] Furthermore, Patent Document 2 discloses a resin composition containing a P3HA-based resin and a biodegradable resin other than a P3HA-based resin, such as polybutylene adipate terephthalate, polybutylene succinate adipate, polybutylene succinate, or polycaprolactone, with the aim of improving excellent flexibility and moldability while increasing the biomass content of the resin composition.

[0020] However, these techniques cannot impart sufficient impact resistance to resin compositions containing P3HA.

[0021] Under these circumstances, the present inventors have discovered that an aliphatic polyester resin composition having excellent impact resistance can be obtained by further adding a biodegradable resin other than P3HA having a glass transition temperature of −10°C or lower, and a peroxide to an aliphatic polyester resin composition containing P3HA.

[0022] While the above-mentioned aliphatic polyester resin compositions were excellent, there was room for improvement in terms of impact resistance. Therefore, through further investigations, the present inventors discovered that an aliphatic polyester resin composition with even better impact resistance can be obtained by previously mixing (e.g., melt-kneading) a portion of the P3HA contained in the aliphatic polyester resin composition with a specific biodegradable resin (i.e., a biodegradable resin other than P3HA that has a glass transition temperature of −10° C. or lower) and a peroxide, allowing them to react, thereby obtaining a compatibilized biodegradable resin containing a reaction product of P3HA, a biodegradable resin other than P3HA that has a glass transition temperature of −10° C. or lower, and a peroxide, and then melt-kneading the obtained compatibilized biodegradable resin with the remaining P3HA. The present inventors, upon detailed investigation of an aliphatic polyester resin composition containing the above-mentioned P3HA and a compatibilized biodegradable resin (i.e., the present aliphatic polyester resin composition), found that the dispersed particle size of the compatibilized biodegradable resin (i.e., the reaction product of P3HA, a biodegradable resin other than P3HA having a glass transition temperature of -10°C or lower, and a peroxide) contained in the present aliphatic polyester resin composition is smaller than that of a resin composition in which P3HA, a biodegradable resin other than P3HA having a glass transition temperature of -10°C or lower, and a peroxide are directly mixed (Figure 1). The inventors speculate that the excellent impact resistance of this aliphatic polyester resin composition is due to the fact that a portion of P3HA is first mixed (e.g., melt-blended) with a biodegradable resin other than P3HA that has a glass transition temperature of −10°C or lower and a peroxide, followed by reaction to obtain a compatibilized biodegradable resin containing the reaction product of P3HA, the biodegradable resin other than P3HA that has a glass transition temperature of −10°C or lower, and the peroxide. This compatibilized biodegradable resin is then mixed with P3HA to form an aliphatic polyester resin composition, which allows the compatibilized biodegradable resin to be more finely dispersed in the resulting aliphatic polyester resin composition, resulting in increased bonding frequency between P3HA and the biodegradable resin other than P3HA that has a glass transition temperature of −10°C or lower, thereby improving the impact resistance of molded articles containing the aliphatic polyester resin composition. It should be noted, however, that the present invention is not limited to this mechanism of action.

[0023] Therefore, the present invention is extremely useful in a variety of fields where biodegradable and impact-resistant resin compositions and molded articles are required.

[0024] Furthermore, the above-described configuration can reduce the amount of plastic waste generated, thereby contributing to the achievement of Sustainable Development Goals (SDGs) such as Goal 12 "Ensure sustainable consumption and production patterns" and Goal 14 "Conserve and sustainably use the oceans and marine resources for sustainable development."

[0025] 2. Aliphatic polyester resin composition <Resin (A)> Resin (A) is a resin containing P3HA. In this specification, resin (A) may be simply referred to as (A).

[0026] The aliphatic polyester resin composition contains P3HA derived from resin (A) and P3HA derived from resin (B). That is, resin (A) contains a portion of the total amount of P3HA contained in the aliphatic polyester resin composition.

[0027] (P3HA) As used herein, "P3HA" refers to a compound represented by the following formula (1): [-O-CHR-CH2-CO-] (1) (Wherein R is C n H 2n+1 and n is an integer of 1 to 15. do.

[0028] There are no particular limitations on P3HA as long as it is included in the above formula (1).

[0029] In one embodiment of the present invention, P3HA may be poly(3-hydroxybutyrate) having only 3-hydroxybutyrate as a repeating unit, or may be a copolymer of 3-hydroxybutyrate and another hydroxyalkanoate.

[0030] In one embodiment of the present invention, P3HA may be a homopolymer, a mixture of a homopolymer and one or more copolymers, or a mixture of two or more copolymers. The type of copolymerization is not particularly limited and may be random copolymerization, alternating copolymerization, block copolymerization, graft copolymerization, etc.

[0031] In one embodiment of the present invention, P3HA includes, for example, poly(3-hydroxybutyrate) (P3HB), poly(3-hydroxybutyrate-co-3-hydroxypropionate) (P3HB3HP), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (P3HB3HH), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (P3HB3HV), poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P3HB4HB), poly(3-hydroxybutyrate-co-3-hydroxyoctanoate) (P3HB3HO), poly(3-hydroxybutyrate-co-3-hydroxyoctadecanoate) (P3HB3HOD), poly(3-hydroxybutyrate-co-3-hydroxydecanoate) (P3HB3HD), poly(3-hydroxybutyrate-co-3-hydroxyvalerate-co-3-hydroxyhexanoate) (P3HB3HV3HH), etc. are included. From the viewpoint of being able to adjust the melting point low and widen the processing range, P3HB3HH, P3HB4HB, and P3HB3HP are preferred. Among them, P3HB3HH and P3HB4HB are particularly preferred because they are easy to produce industrially. From the viewpoint of industrial productivity, in addition to the above, P3HB and P3HB3HV are also preferred.

[0032] In one embodiment of the present invention, it is preferred to exclude "P3HB" and "P3HB3HV" from "P3HA".

[0033] P3HA is preferably produced by a microorganism. The microorganism that produces P3HA is not particularly limited as long as it is capable of producing P3HA. For example, the first P3HB3HH-producing bacterium was Bacillus megaterium, discovered in 1925. Other examples include naturally occurring microorganisms such as Cupriavidus necator (formerly classified as Alcaligenes eutrophus and Ralstonia eutropha) and Alcaligenes latus. It is known that P3HB3HH accumulates intracellularly in these microorganisms.

[0034] Known bacteria that produce copolymers of hydroxybutyrate and other hydroxyalkanoates include Aeromonas caviae, which produces P3HB3HH, and Alcaligenes eutrophus, which produces P3HB4HB. In particular, Alcaligenes eutrophus AC32 (FERM BP-6038) (T. Fukui, Y. Doi, J. Bateriol., 179, pp. 4821-4830 (1997)), which has been introduced with genes encoding P3HB3HH synthases, is preferred for increasing P3HB3HH productivity. These microorganisms are cultured under appropriate conditions to accumulate P3HB3HH within the cells. In addition to the above, genetically modified microorganisms into which various P3HA synthesis-related genes have been introduced may be used depending on the P3HA to be produced, or culture conditions, including the type of substrate, may be optimized.

[0035] P3HB3HH can also be produced by the method described in International Publication No. 2010 / 013483. Commercially available P3HB3HH products include Kaneka Biodegradable Polymer PHBH (registered trademark) manufactured by Kaneka Corporation (e.g., X131A and 151C used in the Examples).

[0036] In one embodiment of the present invention, the composition ratio of the copolymerization components in P3HB3HH is preferably (3-hydroxybutyrate) / (3-hydroxyhexanoate)=99 / 1 to 80 / 20 (mol / mol), more preferably 97 / 3 to 75 / 15 (mol / mol). When the composition ratio of the copolymerization components in P3HB3HH is within the above range, excellent effects can be obtained in terms of the physical properties of the aliphatic polyester resin composition.

[0037] In one embodiment of the present invention, the weight-average molecular weight (hereinafter sometimes referred to as Mw) of P3HA is not particularly limited, but from the viewpoint of moldability, the weight-average molecular weight is preferably 50,000 to 3,000,000, more preferably 100,000 to 2,500,000, and even more preferably 150,000 to 2,000,000. If the weight-average molecular weight of P3HA is less than 50,000, mechanical properties such as strength may be insufficient, and if it exceeds 3,000,000, moldability may be poor.

[0038] The method for measuring the weight-average molecular weight of P3HA is not particularly limited. For example, the weight-average molecular weight can be determined as a polystyrene-equivalent weight-average molecular weight by using chloroform as the mobile phase, a GPC system manufactured by Waters Corporation, and a Shodex K-804 (polystyrene gel) manufactured by Showa Denko K.K. as the column.

[0039] In one embodiment of the present invention, the content of P3HA derived from resin (A) per 100 parts by weight of the aliphatic polyester resin composition is preferably 95 to 50 parts by weight, more preferably 94 to 52 parts by weight, even more preferably 93 to 55 parts by weight, and particularly preferably 91 to 58 parts by weight. When the content of P3HA in resin (A) is 95 parts by weight or less, the addition of resin (B) tends to provide improved impact resistance. On the other hand, when the content is 50 parts by weight or more, an appropriate modulus of elasticity is maintained, making the composition suitable for practical use as a molded article.

[0040] <Resin (B)> Resin (B) is a compatibilized biodegradable resin containing a reaction product of P3HA, a biodegradable resin other than P3HA that has a glass transition temperature of −10°C or lower, and a peroxide. Resin (B) contains a portion of the total amount of P3HA contained in the aliphatic polyester resin composition (i.e., P3HA other than the P3HA derived from resin (A)). In this specification, resin (B) may be simply referred to as (B). In addition, in this specification, the "reaction product of P3HA, a biodegradable resin other than P3HA that has a glass transition temperature of −10°C or lower, and a peroxide" may be simply referred to as the "reaction product."

[0041] The reaction product contained in resin (B) can be said to be a reaction product made from P3HA, a biodegradable resin other than P3HA that has a glass transition temperature of −10° C. or lower, and a peroxide as raw materials. Possible reaction products include, for example, a reaction product in which a biodegradable resin other than P3HA that has a glass transition temperature of −10° C. or lower is grafted onto P3HA.

[0042] Resin (B) can be said to be a compatibilized biodegradable resin containing a reaction product obtained by mixing and reacting P3HA, a biodegradable resin other than P3HA that has a glass transition temperature of -10°C or lower, and a peroxide, and preferably a compatibilized biodegradable resin containing a reaction product obtained by melt-kneading and reacting P3HA, a biodegradable resin other than P3HA that has a glass transition temperature of -10°C or lower, and a peroxide. In this specification, "melt-kneading" means mixing materials with different properties while melting them. The melt-kneading method is not particularly limited, and any method known in the art can be used.

[0043] Furthermore, resin (B) may contain, in addition to the reaction product, unreacted P3HA, a biodegradable resin other than P3HA having a glass transition temperature of −10° C. or lower, and / or a peroxide. That is, resin (B) may contain, in addition to the reaction product, unreacted P3HA, a biodegradable resin other than P3HA having a glass transition temperature of −10° C. or lower, and / or a compatibilized biodegradable resin containing a peroxide.

[0044] In one embodiment of the present invention, the content of resin (B) is preferably 5 to 50 parts by weight, more preferably 6 to 48 parts by weight, even more preferably 7 to 45 parts by weight, and particularly preferably 9 to 42 parts by weight, relative to 100 parts by weight of the aliphatic polyester resin composition. When the content of resin (B) is within the above range, the aliphatic polyester resin composition can provide a molded article that exhibits high impact resistance while having an appropriate elastic modulus for the molded article.

[0045] (P3HA) As for P3HA, which is the raw material of the reaction product contained in resin (B), the same as described above in the section (P3HA) of <Resin (A)> is applicable.

[0046] In one embodiment of the present invention, the type of P3HA contained in resin (B), which is a raw material for the reaction product, may be the same as or different from the P3HA contained in resin (A). For example, as shown in the examples described later, the P3HA contained in resin (A) and the P3HA contained in resin (B) may be the same compound (i.e., PHBH).

[0047] In one embodiment of the present invention, the content of P3HA in resin (B) is preferably 1 to 40 parts by weight, more preferably 2 to 38 parts by weight, even more preferably 3 to 37 parts by weight, and particularly preferably 4 to 35 parts by weight, per 100 parts by weight of the aliphatic polyester resin composition. When the content of P3HA in resin (B) is within the above range, when reacting with a biodegradable resin other than P3HA and a peroxide, the biodegradable resin other than P3HA is efficiently grafted onto P3HA. Note that the content of P3HA refers to the amount of P3HA used (blended amount).

[0048] (Biodegradable resins other than P3HA with a glass transition temperature of -10°C or less) In one embodiment of the present invention, the biodegradable resin other than P3HA that is the raw material for the reaction product is not particularly limited as long as it is a biodegradable resin other than P3HA that has a glass transition temperature of -10°C or lower. In one embodiment of the present invention, the glass transition temperature is -10°C or lower, preferably -15°C or lower, and more preferably -20°C or lower. The effects of the present invention can be achieved by using a biodegradable resin other than P3HA that has a glass transition temperature of -10°C or lower. The lower limit of the glass transition temperature of the biodegradable resin other than P3HA is not particularly limited, but may be, for example, -100°C or higher. In this specification, the term "biodegradable resin" refers to a resin that can be decomposed to the molecular level by the action of microorganisms, ultimately resulting in carbon dioxide and water.

[0049] Examples of biodegradable resins other than P3HA that have a glass transition temperature of -10°C or lower include polybutylene adipate terephthalate (hereinafter sometimes referred to as "PBAT"), polybutylene succinate adipate (hereinafter sometimes referred to as "PBSA"), polybutylene succinate (hereinafter sometimes referred to as "PBS"), polybutylene succinate terephthalate (hereinafter sometimes referred to as "PBST"), polybutylene succinate adipate terephthalate (hereinafter sometimes referred to as "PBSAT"), polybutylene sebacate terephthalate (hereinafter sometimes referred to as "PBSeT"), polybutylene azelate terephthalate (hereinafter sometimes referred to as "PBAzT"), and polycaprolactone (hereinafter sometimes referred to as "PCL").

[0050] In this specification, "PBAT" refers to a random copolymer of 1,4-butanediol, adipic acid, and terephthalic acid. Among these, PBAT obtained by reacting (a) a mixture consisting mainly 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 1,4-butanediol (wherein the molar ratio of (a) to (b) is 0.4:1 to 1.5:1), as described in JP-A-10-508640, is preferred. In one embodiment of the present invention, 1,4-butanediol may be replaced with glycol compounds such as ethylene glycol, propylene glycol, heptanediol, hexanediol, octanediol, nonanediol, decanediol, 1,4-cyclohexanedimethanol, neopentyl glycol, glycerin, pentaerythritol, bisphenol A, polyethylene glycol, polypropylene glycol, and polytetramethylene glycol. In one embodiment of the present invention, adipic acid may be replaced with dicarboxylic acids such as oxalic acid, succinic acid, azelaic acid, dodecanedioic acid, malonic acid, glutaric acid, cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, bis(p-carboxyphenyl)methane, anthracenedicarboxylic acid, 4,4'-diphenyletherdicarboxylic acid, 5-sodium sulfoisophthalic acid, and 5-tetrabutylphosphonium isophthalic acid. Commercially available PBAT products include, for example, "Ecoflex C1200" manufactured by BASF.

[0051] In this specification, "PBSA" refers to an aliphatic polyester copolymer synthesized by an esterification reaction and a condensation polymerization reaction between an aliphatic diol component mainly composed of 1,4-butanediol, an aliphatic dicarboxylic acid component mainly composed of succinic acid such as succinic acid and / or its derivatives, and adipic acid. Commercially available products include "BioPBS FD72" and "BioPBS FD92" manufactured by Mitsubishi Chemical Corporation, and these can be used alone or in combination of two or more.

[0052] In this specification, "PBS" refers to an aliphatic polyester copolymer synthesized by an esterification reaction and / or transesterification reaction, and a condensation polymerization reaction, between an aliphatic diol component primarily composed of 1,4-butanediol and an aliphatic dicarboxylic acid component primarily composed of succinic acid, such as succinic acid and / or its derivatives. Commercially available products include "BioPBS FZ71" and "BioPBS FZ91" manufactured by Mitsubishi Chemical Corporation, and these can be used alone or in combination of two or more.

[0053] In this specification, "PBST" refers to the above-mentioned PBS into which a terephthalate unit has been introduced, and more specifically refers to an aliphatic aromatic polyester copolymer synthesized by an esterification reaction and a condensation polymerization reaction between an aliphatic dicarboxylic acid component, the main component of which is a succinic acid component such as succinic acid and / or a derivative thereof, and terephthalic acid.

[0054] In this specification, "PBSAT" refers to a copolymer containing aliphatic dicarboxylic acid residues, preferably succinic acid: adipic acid: phthalic acid residues, in a ratio of 70-90:5-15:5-15 mol %. Therefore, to produce PBSAT, the dicarboxylic acids in the above ratio and the aliphatic glycol 1,4-butanediol are used in a molar ratio of 1:1.2-2.0 to undergo an esterification reaction, followed by a condensation polymerization reaction. The reactive groups and reaction conditions used in the reaction can be those used in existing biodegradable resins such as PBS.

[0055] As used herein, “PBSeT” refers to the PBAT in which the “adipic acid or an ester-forming derivative thereof” is replaced with “sebacic acid or an ester-forming derivative thereof.” Commercially available PBSeT products include, for example, BASF’s “Ecoflex FS blend C2200” (registered trademark).

[0056] As used herein, "PBAzT" refers to the PBAT in which the "adipic acid or an ester-forming derivative thereof" portion has been replaced with "azelaic acid or an ester-forming derivative thereof."

[0057] As used herein, "PCL" refers to a compound represented by the following formula (2): [-(CH2)5-CO-O-] (2) PCL refers to a polymer having a monomer unit represented by the formula: PCL is typically obtained by ring-opening polymerization of ε-caprolactone using a cationic or anionic initiator, for example, an active hydrogen compound such as an alcohol, as an initiator. However, the present invention is not limited to this method, and PCL obtained by other production methods can also be used. An organometallic catalyst can also be used to promote the polymerization of PCL. Furthermore, the end-capping structure of PCL is not particularly limited. The PCL used in one embodiment of the present invention typically has a melting point of 50 to 65°C, a crystallization temperature of 10 to 30°C, and a glass transition point of -50 to -60°C.

[0058] The weight-average molecular weight of PCL is preferably 30,000 to 500,000, more preferably 100,000 to 400,000. If the weight-average molecular weight of PCL is less than 30,000, the aliphatic polyester resin composition may become brittle. If the weight-average molecular weight of PCL is more than 500,000, the aliphatic polyester resin composition may become difficult to process.

[0059] Commercially available PCL products include, for example, Ingevity's "Capa 6506" (powder, Mw = 130,000), "Capa 6500" (pellet, Mw = 130,000), "Capa 6806" (powder, Mw = 230,000), "Capa 6800" (pellet, Mw = 230,000), and "FB100" (pellet, Mw = 300,000, contains PCL crosslinked material), and these can be used alone or in combination of two or more.

[0060] In one embodiment of the present invention, the biodegradable resin other than P3HA having a glass transition temperature of −10° C. or lower may be used alone or in combination.

[0061] In one embodiment of the present invention, the biodegradable resin other than P3HA having a glass transition temperature of −10° C. or lower is preferably at least one selected from the group consisting of PBAT, PBSA, PBS, PBST, PBSAT, PBSeT, PBAzT, and PCL.

[0062] In one embodiment of the present invention, the content of the biodegradable resin other than P3HA having a glass transition temperature of -10°C or lower is preferably 5 to 40 parts by weight, more preferably 6 to 38 parts by weight, even more preferably 7 to 36 parts by weight, and particularly preferably 8 to 35 parts by weight, per 100 parts by weight of the aliphatic polyester resin composition, from the viewpoint of the balance between the biomass plastic content and physical properties. Note that the content of the biodegradable resin other than P3HA having a glass transition temperature of -10°C or lower refers to the amount used (blended amount) of the biodegradable resin other than P3HA having a glass transition temperature of -10°C or lower.

[0063] In one embodiment of the present invention, the dispersed particle size of (B) in the aliphatic polyester resin composition (i.e., a compatibilized biodegradable resin containing a reaction product of P3HA, a biodegradable resin other than P3HA having a glass transition temperature of −10° C. or lower, and a peroxide) is, from the viewpoint of excellent impact resistance, for example, 1.5 μm or less, preferably 1.3 μm or less, and more preferably 1.0 μm or less. The lower limit of the dispersed particle size is not particularly limited, and is, from the viewpoint of excellent impact resistance, the smaller the better, but is, for example, 0.1 μm or more, preferably 0.15 μm or more, and more preferably 0.2 μm or more. The dispersed particle size is measured by the method described in the Examples. The dispersed particle size of (B) in the aliphatic polyester resin composition can also be said to be the dispersed particle size of particles derived from (B) in the aliphatic polyester resin composition. In this specification, particles derived from (B) refer to particles containing at least a reaction product of P3HA, a biodegradable resin other than P3HA having a glass transition temperature of -10°C or lower, and a peroxide, and optionally particles containing P3HA, a biodegradable resin other than P3HA having a glass transition temperature of -10°C or lower, and / or a peroxide.

[0064] (peroxide) Resin (B) contains a peroxide, which is a raw material for the reaction product. That is, the aliphatic polyester resin composition may be a composition containing a peroxide in addition to P3HA or a biodegradable resin other than P3HA that has a glass transition temperature of −10° C. or lower. The peroxide, which is a raw material for the reaction product, may be an organic peroxide or an inorganic peroxide. Among these, organic peroxides are preferred, as they can be used with a one-minute half-life temperature suitable for the melt-kneading temperature.

[0065] In one embodiment of the present invention, the organic peroxide is not particularly limited and any known organic peroxide can be used. However, taking into consideration the melting temperature, kneading time, etc., it is preferable for the organic peroxide to have a high ability to abstract hydrogen from P3HA and a structure that does not contain aromatic rings in the molecule that would cause coloration of P3HA, and more preferably has a 1-minute half-life temperature of 180°C or less.

[0066] In this specification, the "one-minute half-life temperature" refers to the temperature at which the organic peroxide is thermally decomposed to half its original volume in one minute. The one-minute half-life temperature is preferably 145 to 165°C, as this promotes the decomposition of the organic peroxide and allows the crosslinking reaction to occur after the organic peroxide is uniformly dispersed. If the one-minute half-life temperature of the organic peroxide used is higher than 180°C, the organic peroxide must be extruded at a temperature higher than 180°C to react with P3HA. However, the P3HA undergoes thermal decomposition, causing a decrease in molecular weight, making the extrusion unstable. This tends to result in non-uniformity in the resulting aliphatic polyester resin composition and its molded article.

[0067] As the organic peroxide, for example, diacyl peroxide, peroxy ester, dialkyl peroxide, hydroperoxide, peroxy ketal, peroxy carbonate, etc. are preferably used in consideration of the melting temperature, kneading time, etc. Specifically, butyl peroxyneododecanoate, octanoyl peroxide, dilauroyl peroxide, succinic peroxide, a mixture of toluoyl peroxide and benzoyl peroxide, benzoyl peroxide, bis(butylperoxy)trimethylcyclohexane, butyl peroxylaurate, dimethyldi(benzoylperoxy)hexane, bis(butylperoxy)methylcyclohexane, bis(butylperoxy)cyclohexane, butyl peroxybenzoate, butyl bis(butylperoxy)valerate, dicumyl peroxide, t-butylperoxymethyl monocarbonate, t-pentylperoxymethyl monocarbonate, t-hexylperoxymethyl monocarbonate, t-heptylperoxymethyl monocarbonate, t-octylperoxymethyl monocarbonate, 1,1,3,3-tetramethylbutylperoxymethyl monocarbonate, and t-butylperoxyethyl monocarbonate. peroxyethyl monocarbonate, t-pentylperoxyethyl monocarbonate, t-hexylperoxyethyl monocarbonate, t-heptylperoxyethyl monocarbonate, t-octylperoxyethyl monocarbonate, 1,1,3,3-tetramethylbutylperoxyethyl monocarbonate, t-butylperoxy-n-propyl monocarbonate, t-pentylperoxy-n-propyl monocarbonate, t-hexylperoxy-n-propyl monocarbonate, t-heptylperoxy peroxy-n-propyl monocarbonate, t-octylperoxy-n-propyl monocarbonate, 1,1,3,3-tetramethylbutylperoxy-n-propyl monocarbonate, t-butylperoxyisopropyl monocarbonate, t-pentylperoxyisopropyl monocarbonate, t-hexylperoxyisopropyl monocarbonate, t-heptylperoxyisopropyl monocarbonate, t-octylperoxyisopropyl monocarbonate, 1,1,3,3-Tetramethylbutylperoxyisopropyl monocarbonate, t-butylperoxyn-butyl monocarbonate, t-pentylperoxyn-butyl monocarbonate, t-hexylperoxyn-butyl monocarbonate, t-heptylperoxyn-butyl monocarbonate, t-octylperoxyn-butyl monocarbonate, 1,1,3,3-tetramethylbutylperoxyn-butyl monocarbonate, t-butylperoxyisobutyl monocarbonate, t-pentylperoxyisobutyl monocarbonate, t -Hexylperoxyisobutyl monocarbonate, t-heptylperoxyisobutyl monocarbonate, t-octylperoxyisobutyl monocarbonate, 1,1,3,3-tetramethylbutylperoxyisobutyl monocarbonate, t-butylperoxysec-butyl monocarbonate, t-pentylperoxysec-butyl monocarbonate, t-hexylperoxysec-butyl monocarbonate, t-heptylperoxysec-butyl monocarbonate, t-octylperoxysec-butyl monocarbonate t-butylperoxy t-butyl monocarbonate, 1,1,3,3-tetramethylbutylperoxy sec-butyl monocarbonate, t-butylperoxy t-butyl monocarbonate, t-pentylperoxy t-butyl monocarbonate, t-hexylperoxy t-butyl monocarbonate, t-heptylperoxy t-butyl monocarbonate, t-octylperoxy t-butyl monocarbonate, 1,1,3,3-tetramethylbutylperoxy t-butyl monocarbonate, t-butylperoxy 2-ethylhexyl monocarbonate, t-pentylperoxy 2-ethylhexyl monocarbonate ethylhexyl monocarbonate, t-hexylperoxy 2-ethylhexyl monocarbonate, t-heptylperoxy 2-ethylhexyl monocarbonate, t-octylperoxy 2-ethylhexyl monocarbonate, 1,1,3,3-tetramethylbutylperoxy 2-ethylhexyl monocarbonate, diisobutyl peroxide, cumyl peroxy neodecanoate, di-n-propyl peroxydicarbonate, diisopropyl peroxydicarbonate, di-sec-butyl peroxydicarbonate, 1,1,3,3-Tetramethylbutylperoxyneodecanoate, bis(4-t-butylcyclohexyl)peroxydicarbonate, bis(2-ethylhexyl)peroxydicarbonate, t-hexylperoxyneodecanoate, t-butylperoxyneodecanoate, t-butylperoxyneoheptanoate, t-hexylperoxypivalate, t-butylperoxypivalate, di(3,5,5-trimethylhexanoyl)peroxide, dilauroyl peroxide, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, disuccinic acid peroxide, 2,5-dimethyl-2,5-bis(2-ethylhexanoylperoxy) Examples of peroxyl groups include hexane, t-hexylperoxy-2-ethylhexanoate, di(4-methylbenzoyl)peroxide, dibenzoyl peroxide, t-butylperoxy-2-ethylhexyl carbonate, t-butylperoxyisopropyl carbonate, 1,6-bis(t-butylperoxycarbonyloxy)hexane, t-butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxyacetate, t-butylperoxybenzoate, t-amylperoxy-3,5,5-trimethylhexanoate, 2,2-bis(4,4-di-t-butylperoxycyclohexyl)propane, and 2,2-di-t-butylperoxybutane.

[0068] Among these, t-butylperoxyisopropyl monocarbonate, t-pentylperoxyisopropyl monocarbonate, t-hexylperoxyisopropyl monocarbonate, t-butylperoxy2-ethylhexyl monocarbonate, t-pentylperoxy2-ethylhexyl monocarbonate, and t-hexylperoxy2-ethylhexyl monocarbonate are more preferred because they have good hydrogen abstraction ability and a 1-minute half-life temperature of 145 to 165°C.

[0069] These organic peroxides may be used alone or in combination of two or more.

[0070] Examples of inorganic peroxides include hydrogen peroxide, potassium peroxide, calcium peroxide, sodium peroxide, magnesium peroxide, potassium persulfate, sodium persulfate, and ammonium persulfate.

[0071] Among these, potassium persulfate, sodium persulfate, and ammonium persulfate are more preferred because they are easy to handle and have decomposition temperatures suitable for the melt-kneading temperature.

[0072] These inorganic peroxides may be used alone or in combination of two or more thereof. It is also possible to use the above organic peroxides and the above inorganic peroxides in combination.

[0073] In one embodiment of the present invention, the content of the peroxide is preferably 0.01 to 0.50 parts by weight, more preferably 0.015 to 0.48 parts by weight, even more preferably 0.020 to 0.45 parts by weight, and particularly preferably 0.025 to 0.43 parts by weight, per 100 parts by weight of the aliphatic polyester resin composition. When the content of the peroxide is within the above range, excessive condensation polymerization reactions are suppressed, and branching and crosslinking reactions proceed efficiently, resulting in a long-chain branched / crosslinked / high-molecular-weight aliphatic polyester resin composition that produces almost no impurities such as gel. Note that the content of the peroxide refers to the amount of peroxide used (blended amount).

[0074] <Nucleating agents / lubricants> In one embodiment of the present invention, the aliphatic polyester resin composition may further contain a crystal nucleating agent and / or a lubricant. When the aliphatic polyester resin composition contains a crystal nucleating agent, it has the effect of improving molding processability, productivity, etc. Furthermore, when the aliphatic polyester resin composition contains a lubricant, it has the effect of improving the surface smoothness of the molded article.

[0075] In one embodiment of the present invention, the nucleating agent and / or lubricant can be incorporated into the present aliphatic polyester resin composition, for example, by mixing (preferably melt-kneading) the resin (A) with the resin (B) before mixing (preferably melt-kneading) the resin (A).

[0076] In addition, in one embodiment of the present invention, the crystal nucleating agent and / or lubricant can be added when the resin (A) and the resin (B) are mixed (e.g., melt-kneaded), and thereby contained in the present aliphatic polyester resin composition.

[0077] The crystal nucleating agent is not particularly limited as long as it has the above-mentioned effect, and examples thereof include inorganic substances such as pentaerythritol, boron nitride, titanium oxide, talc, layered silicates, calcium carbonate, sodium chloride, and metal phosphates; sugar alcohol compounds derived from natural products such as erythritol, galactitol, mannitol, and arabitol; polyvinyl alcohol, chitin, chitosan, polyethylene oxide, aliphatic carboxylic acid amides, aliphatic carboxylic acid salts, aliphatic alcohols, aliphatic carboxylic acid esters, dimethyl adipate, dibutyl adipate, and diisodecyl Examples of suitable crystal nucleating agents include dicarboxylic acid derivatives such as adipate and dibutyl sebacate; cyclic compounds such as indigo, quinacridone, and quinacridone magenta, which have a functional group C=O and a functional group selected from NH, S, and O in the molecule; sorbitol derivatives such as bisbenzylidene sorbitol and bis(p-methylbenzylidene) sorbitol; compounds containing a nitrogen-containing heteroaromatic nucleus such as pyridine, triazine, and imidazole; phosphate ester compounds, bisamides of higher fatty acids, and metal salts of higher fatty acids; branched polylactic acid; and low-molecular-weight poly(3-hydroxybutyrate). These crystal nucleating agents may be used alone or in combination of two or more.

[0078] The content of the nucleating agent is not particularly limited as long as it can promote the crystallization of P3HA, but is preferably 0.5 to 2.0 parts by weight, more preferably 0.6 to 1.8 parts by weight, even more preferably 0.7 to 1.6 parts by weight, and particularly preferably 0.8 to 1.5 parts by weight, relative to 100 parts by weight of the aliphatic polyester resin composition. If the content of the nucleating agent is too low (for example, less than 0.5 parts by weight), the effect of the nucleating agent may not be obtained, while if the content of the nucleating agent is too high (for example, more than 2.0 parts by weight), there may be effects such as a decrease in viscosity during processing and physical properties of the molded product.

[0079] In one embodiment of the present invention, the lubricant contains at least one selected from the group consisting of behenamide, stearamide, erucamide, and oleamide. This provides the resulting molded article with lubricity (particularly external lubricity). Among behenamide, stearamide, erucamide, and oleamide, it is preferable to contain behenamide or erucamide from the viewpoint of improving processability and productivity.

[0080] In one embodiment of the present invention, the lubricant may be behenamide, stearamide, erucamide, oleamide, or a combination of two or more of these, or may be a combination with a lubricant other than behenamide, stearamide, erucamide, or oleamide (hereinafter referred to as "other lubricants"). Examples of other lubricants include, but are not limited to, alkylene fatty acid amides such as methylene bisstearic acid amide and ethylene bisstearic acid amide; polyethylene wax, oxidized polyester wax, glycerin monofatty acid esters such as glycerin monostearate, glycerin monobehenate, and glycerin monolaurate; organic acid monoglycerides such as succinic acid saturated fatty acid monoglycerides; sorbitan fatty acid esters such as sorbitan behenate, sorbitan stearate, and sorbitan laurate; polyglycerin fatty acid esters such as diglycerin stearate, diglycerin laurate, tetraglycerin stearate, tetraglycerin laurate, decaglycerin stearate, and decaglycerin laurate; and higher alcohol fatty acid esters such as stearyl stearate. The above-mentioned other lubricants may be used alone or in combination of two or more.

[0081] The content of the lubricant (when multiple lubricants are used, the total content) is not particularly limited as long as it can provide lubrication, but is preferably 0.1 to 2.0 parts by weight, more preferably 0.2 to 1.6 parts by weight, even more preferably 0.3 to 1.4 parts by weight, and particularly preferably 0.4 to 1.2 parts by weight, relative to 100 parts by weight of the aliphatic polyester resin composition. If the content of the lubricant is too low (for example, less than 0.1 part by weight), the effect may not be exhibited, whereas if the content of the lubricant is too high (for example, more than 2.0 parts by weight), the lubricant may bleed out onto the surface of the molded article, damaging the appearance of the surface of the molded article.

[0082] <Other ingredients> In addition to the P3HA, a biodegradable resin other than P3HA having a glass transition temperature of −10° C. or lower, a peroxide, a crystal nucleating agent, and / or a lubricant, the aliphatic polyester resin composition may contain other components such as plasticizers, inorganic fillers, antioxidants, ultraviolet absorbers, colorants such as dyes and pigments, and antistatic agents, to the extent that the functionality of the resulting molded article containing the aliphatic polyester resin composition is not impaired.

[0083] The plasticizer is not particularly limited, but examples thereof include modified glycerin-based compounds such as glycerin diacetomonolaurate, glycerin diacetomonocaprylate, and glycerin diacetomonodecanoate; adipate-based compounds such as diethylhexyl adipate, dioctyl adipate, and diisononyl adipate; polyether ester-based compounds such as polyethylene glycol dibenzoate, polyethylene glycol dicaprylate, and polyethylene glycol diisostearate; benzoate-based compounds; epoxidized soybean oil; epoxidized fatty acid 2-ethylhexyl; and sebacic acid monoesters. These may be used alone or in combination of two or more. Among the above plasticizers, modified glycerin-based compounds and polyether ester-based compounds are preferred due to their ease of availability and high effectiveness. These may be used alone or in combination of two or more.

[0084] The inorganic filler is not particularly limited, but examples thereof include clay, synthetic silicon, carbon black, barium sulfate, mica, glass fiber, whisker, carbon fiber, calcium carbonate, magnesium carbonate, glass powder, metal powder, kaolin, graphite, molybdenum disulfide, zinc oxide, etc. These may be used alone or in combination of two or more.

[0085] The antioxidant is not particularly limited, but examples thereof include phenol-based antioxidants, phosphorus-based antioxidants, sulfur-based antioxidants, etc. These may be used alone or in combination of two or more.

[0086] The ultraviolet absorber is not particularly limited, but examples thereof include benzophenone compounds, benzotriazole compounds, triazine compounds, salicylic acid compounds, cyanoacrylate compounds, nickel complex salt compounds, etc. These may be used alone or in combination of two or more.

[0087] The colorant such as a pigment or dye is not particularly limited, but examples thereof include inorganic colorants such as titanium oxide, calcium carbonate, chromium oxide, cuprous oxide, calcium silicate, iron oxide, carbon black, graphite, titanium yellow, and cobalt blue, soluble azo pigments such as lake red, lithol red, and brilliant carmine, insoluble azo pigments such as dinitrian orange and fast yellow, phthalocyanine pigments such as monochlorophthalocyanine blue, polychlorophthalocyanine blue, and polybromophthalocyanine green, condensed polycyclic pigments such as indigo blue, perylene red, isoindolinone yellow, and quinacridone red, and dyes such as oracet yellow. These may be used alone or in combination of two or more.

[0088] The antistatic agent is not particularly limited, but examples thereof include low molecular weight antistatic agents such as fatty acid ester compounds, aliphatic ethanolamine compounds, and aliphatic ethanolamide compounds, and polymeric antistatic agents, etc. These may be used alone or in combination of two or more.

[0089] The content of each of the above components is not particularly limited as long as the effects of the present invention can be exhibited, and can be appropriately determined by a person skilled in the art.

[0090] 3. Method for producing aliphatic polyester resin composition A method for producing an aliphatic polyester resin composition according to one embodiment of the present invention (hereinafter referred to as "this production method") is characterized by comprising: (a) a step of melt-kneading poly(3-hydroxyalkanoate), a biodegradable resin other than poly(3-hydroxyalkanoate) having a glass transition temperature of -10°C or lower, and a peroxide to obtain a compatibilized biodegradable resin; and (b) a step of melt-kneading the compatibilized biodegradable resin obtained in step (a) with poly(3-hydroxyalkanoate) to obtain an aliphatic polyester resin composition.

[0091] This production method first involves (i) mixing (preferably melt-kneading) P3HA, a biodegradable resin other than P3HA that has a glass transition temperature of −10°C or lower, a peroxide, and, if necessary, a nucleating agent, a lubricant, and other additives using an extruder, kneader, Banbury mixer, rolls, or the like to produce pellets of a compatibilized biodegradable resin. Step (i) can be described as a process of reacting P3HA, a biodegradable resin other than P3HA that has a glass transition temperature of −10°C or lower, and a peroxide to obtain a reaction product, or alternatively, a process of obtaining resin (B). Next, separately from step (i), (ii) is performed to melt-knead P3HA, and, if necessary, a nucleating agent, a lubricant, and other additives using an extruder, kneader, Banbury mixer, rolls, or the like to produce pellets of a resin containing P3HA. Step (ii) can be described as a process of obtaining resin (A). Next, the two pellets (i.e., the pellets made of the compatibilized biodegradable resin obtained in step (i) and the pellets made of the resin containing P3HA obtained in step (ii)) are melt-kneaded using an extruder, kneader, Banbury mixer, roll, etc. to obtain an aliphatic polyester resin composition. Finally, the aliphatic polyester resin composition obtained in the above step is extruded into a strand shape and then cut, to obtain a molded article containing the aliphatic polyester resin composition in a particle shape such as a bar shape, a cylindrical shape, an elliptical cylinder shape, a sphere shape, a cube shape, or a rectangular parallelepiped shape.

[0092] In the melt-kneading step, (i) the temperature at which P3HA, a biodegradable resin other than P3HA with a glass transition temperature of -10°C or lower, a peroxide, and, if necessary, a crystal nucleating agent, a lubricant, and other additives are melt-kneaded, and (ii) the temperature at which P3HA, a crystal nucleating agent, a lubricant, and other additives are melt-kneaded, if necessary, vary depending on the melting point, melt viscosity, etc. of the P3HA used and the melt viscosity, etc. of the biodegradable resin other than P3HA with a glass transition temperature of -10°C or lower, and therefore cannot be generally specified. However, the temperature at the die outlet of the melt-kneaded product is preferably 120 to 200°C, more preferably 125 to 195°C, and even more preferably 130 to 190°C. If the temperature at the die outlet of the melt-kneaded product is less than 120°C, biodegradable resins other than P3HA with a glass transition temperature of -10°C or lower may be poorly dispersed, and if it exceeds 200°C, P3HA may be thermally decomposed.

[0093] In this manufacturing method, <p3ha>、<Biodegradable resins with a glass transition temperature of -10°C or lower other than P3HA>, <peroxides>, <crystallization nucleating agents and lubricants>, and <other components> are incorporated by reference for the content described in each item.

[0094] Also, in this section, as an example of this production method, a method of mixing each component (P3HA, biodegradable resins with a glass transition temperature of -10°C or lower other than P3HA, peroxides, etc.) by melt-kneading was described, but this production method is not limited thereto.

[0095] [4. Molded article containing aliphatic polyester resin composition] The molded article according to an embodiment of the present invention (hereinafter referred to as "this molded article") contains this aliphatic polyester resin composition.

[0096] This molded article is not particularly limited as long as it contains this aliphatic polyester resin composition, and examples include paper, film, sheet, tube, plate, rod, container (e.g., bottle container), food tray, bag, parts, etc.

[0097] Also, in an embodiment of the present invention, in order to improve its physical properties, this molded article can be combined with a molded article made of a material different from this molded article (e.g., fiber, thread, rope, woven fabric, knitted fabric, non-woven fabric, paper, film, sheet, tube, plate, rod, container, bag, parts, foam, etc.). These materials are also preferably biodegradable.

[0098] In an embodiment of the present invention, from the viewpoint of excellent impact resistance, the 50% fracture energy at a measurement temperature of 25°C is, for example, 0.5 J or more, preferably 0.8 J or more, and more preferably 1.0 J or more. The higher the 50% fracture energy at a measurement temperature of 25°C, the better, and the upper limit is not particularly limited, but for example, it is 30 J or less.

[0099] In one embodiment of the present invention, the 50% breaking energy when the measurement temperature is 0°C is, from the viewpoint of excellent impact resistance, for example, 0.12 J or more, preferably 0.14 J or more, and more preferably 0.15 J or more. The 50% breaking energy when the measurement temperature is 25°C is preferably as high as possible, and there is no particular upper limit, but it is, for example, 30 J or less. The 50% breaking energy is measured by the method described in the examples.

[0100] In one embodiment of the present invention, the 50% fracture energy of the present aliphatic polyester resin composition may vary depending on the content of biodegradable resins other than P3HA having a glass transition temperature of −10°C or lower in the present aliphatic polyester resin composition and the temperature at which the 50% fracture energy is measured.

[0101] In one embodiment of the present invention, when the content of a biodegradable resin other than P3HA having a glass transition temperature of -10°C or lower is 10 parts by weight, the 50% fracture energy at a measurement temperature of 25°C is preferably 0.3 J or more, more preferably 0.5 J or more, and even more preferably 0.7 J or more. Furthermore, in one embodiment of the present invention, when the content of a biodegradable resin other than P3HA having a glass transition temperature of -10°C or lower is 10 parts by weight, the 50% fracture energy at a measurement temperature of 0°C is preferably 0.11 J or more, more preferably 0.13 J or more, and even more preferably 0.15 J or more.

[0102] In one embodiment of the present invention, when the content of a biodegradable resin other than P3HA having a glass transition temperature of -10°C or lower is 20 parts by weight, the 50% fracture energy at a measurement temperature of 25°C is preferably 5.0 J or more, more preferably 7.0 J or more, and even more preferably 9.0 J or more. Furthermore, in one embodiment of the present invention, when the content of a biodegradable resin other than P3HA having a glass transition temperature of -10°C or lower is 20 parts by weight, the 50% fracture energy at a measurement temperature of 0°C is preferably 1.0 J or more, more preferably 2.0 J or more, and even more preferably 3.0 J or more.

[0103] In one embodiment of the present invention, when the content of a biodegradable resin other than P3HA having a glass transition temperature of −10°C or lower is 30 parts by weight, the 50% fracture energy at a measurement temperature of 0°C is preferably 8.1 J or more, more preferably 8.5 J or more, and even more preferably 9.0 J or more.

[0104] In one embodiment of the present invention, the molded article is obtained by molding an aliphatic polyester resin composition obtained by the method described above in Section 3. Manufacturing Method of Aliphatic Polyester Resin Composition. Examples of such methods include injection molding, injection compression molding, gas-assisted molding, and other injection molding methods commonly used in molding thermoplastic resins, as well as cast molding, blow molding, and inflation molding. Furthermore, in addition to the above methods, other methods such as in-mold molding, gas press molding, two-color molding, sandwich molding, push-pull molding, and scorim molding can also be used depending on the purpose. However, the injection molding method is not limited to these. The molding temperature during injection molding is preferably 140 to 190°C, and the mold temperature is preferably 20 to 80°C, more preferably 30 to 70°C.

[0105] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention.

[0106] That is, one embodiment of the present invention is as follows. <1> An aliphatic polyester resin composition containing the following (A) and (B): (A) poly(3-hydroxyalkanoate), (B) a compatibilized biodegradable resin containing a reaction product of poly(3-hydroxyalkanoate), a biodegradable resin other than poly(3-hydroxyalkanoate) having a glass transition temperature of −10° C. or lower, and a peroxide; An aliphatic polyester resin composition, wherein the dispersed particles of (B) in the aliphatic polyester resin composition have a diameter of 0.1 to 1.5 μm. <2> The content of (B) is 5 to 50 parts by weight relative to 100 parts by weight of the aliphatic polyester resin composition. <1> The aliphatic polyester resin composition according to claim 1. <3> The content of the peroxide is 0.01 to 0.5 parts by weight relative to 100 parts by weight of the aliphatic polyester resin composition. <1> or <2> The aliphatic polyester resin composition according to claim 1. <4> The biodegradable resin (B) other than poly(3-hydroxyalkanoate) and having a glass transition temperature of −10° C. or lower is at least one selected from the group consisting of polybutylene adipate terephthalate, polybutylene succinate adipate, polybutylene succinate, polybutylene succinate terephthalate, polybutylene succinate adipate terephthalate, polybutylene sebacate terephthalate, polybutylene azelate terephthalate, and polycaprolactone. <1> ~ <3> 1. The aliphatic polyester resin composition according to claim 1 . <5> The peroxide is an organic peroxide having a one-minute half-life temperature of 180°C or less. <1> ~ <4> 1. The aliphatic polyester resin composition according to claim 1 . <6> The peroxide is at least one selected from the group consisting of t-butylperoxyisopropyl monocarbonate, t-pentylperoxyisopropyl monocarbonate, t-hexylperoxyisopropyl monocarbonate, t-butylperoxy 2-ethylhexyl monocarbonate, t-pentylperoxy 2-ethylhexyl monocarbonate, and t-hexylperoxy 2-ethylhexyl monocarbonate. <1> ~ <5> 1. The aliphatic polyester resin composition according to claim 1 . <7> Further comprising a nucleating agent and / or a lubricant, <1> ~ <6> 1. The aliphatic polyester resin composition according to claim 1 . <8> The compatibilized biodegradable resin is obtained by melt-kneading the poly(3-hydroxyalkanoate), a biodegradable resin other than the poly(3-hydroxyalkanoate) having a glass transition temperature of −10° C. or lower, and the peroxide. <1> ~ <7> 1. The aliphatic polyester resin composition according to claim 1 . <9> The aliphatic polyester resin composition is obtained by melt-kneading the (A) and the (B). <1> ~ <8> 1. The aliphatic polyester resin composition according to claim 1 . <10> <1> ~ <9> 2. A molded article comprising the aliphatic polyester resin composition according to claim 1. <11> (a) melt-kneading poly(3-hydroxyalkanoate), a biodegradable resin other than poly(3-hydroxyalkanoate) having a glass transition temperature of −10° C. or lower, and a peroxide to obtain a compatibilized biodegradable resin; (b) A step of melt-kneading the compatibilized biodegradable resin obtained in the step (a) with poly(3-hydroxyalkanoate) to obtain an aliphatic polyester resin composition. A method for producing an aliphatic polyester resin composition, comprising: <12> the amount of the compatibilizing biodegradable resin in the step (b) is 5 to 50 parts by weight relative to 100 parts by weight of the aliphatic polyester resin composition; <11> The manufacturing method described in <13> the amount of peroxide in the step (a) is 0.01 to 0.5 parts by weight relative to 100 parts by weight of the aliphatic polyester resin composition; <11> or <12> The manufacturing method described in <14> the biodegradable resin other than poly(3-hydroxyalkanoate) having a glass transition temperature of −10° C. or lower in the step (a) is at least one selected from the group consisting of polybutylene adipate terephthalate, polybutylene succinate adipate, polybutylene succinate, polybutylene succinate terephthalate, polybutylene succinate adipate terephthalate, polybutylene sebacate terephthalate, polybutylene azelate terephthalate, and polycaprolactone; <11> ~ <13> 1. The manufacturing method according to any one of the preceding claims. <15> The peroxide in the step (a) is an organic peroxide having a one-minute half-life temperature of 180°C or less. <11> ~ <14> 1. The manufacturing method according to any one of the preceding claims. [Example]

[0107] The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to these examples in any way.

[0108] 〔material〕 (P3HA) The following resins were used as P3HA: Kaneka Biodegradable Polymer PHBH (registered trademark) X131A [Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)] manufactured by Kaneka Kaneka Biodegradable Polymer PHBH (registered trademark) 151C [Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)] manufactured by Kaneka.

[0109] (Biodegradable resins other than P3HA with a glass transition temperature of -10°C or less) As a biodegradable resin other than P3HA with a glass transition temperature of -10°C or less, PBAT (BASF "Ecoflex C1200", glass transition temperature: -30°C) was used.

[0110] (peroxide) The peroxide used was t-butylperoxyisopropyl monocarbonate ("Perbutyl I" manufactured by NOF Corporation). In this specification, "Perbutyl I" is also referred to as "PBI."

[0111] (nucleating agent) Pentaerythritol ("Neurizer P" manufactured by Mitsubishi Chemical Corporation) was used as a crystal nucleating agent. In this specification, "Neurizer P" is also referred to as "PETL."

[0112] [Measurement and evaluation methods] (50% breaking energy) The 50% fracture energy was measured using a DuPont drop impact tester (manufactured by Toyo Seiki Seisakusho) in accordance with ASTM D 2794 after aging the molded articles (test specimens) obtained in the examples and comparative examples in a constant-temperature room at 25°C for 7 days (test specimen thickness: 1.0 mm, iron ball weight: 0.3 to 2.0 kg, impact point radius: 7.9 mm, measurement temperature: 25°C or 0°C, 20 measurements, unit: J). The 50% fracture height was measured and the 50% fracture energy was calculated from this value. The higher the 50% fracture energy, the better the impact resistance. A measured 50% fracture energy greater than 20.6 J was recorded as ">20.6 J," and a 50% fracture energy less than 0.01 J was recorded as "<0.01 J."

[0113] (Dispersed particle size) The dispersed particle size of the compatibilized biodegradable resin in the molded body was measured as follows: The cross sections of the molded bodies (test pieces) obtained in the Examples and Comparative Examples were observed with a transmission electron microscope, and the average particle size of the observed particles was taken as the dispersed particle size.

[0114] Example 1 (Pellet production) A mixture of 85 parts by weight of X131A and 1 part by weight of PETL, which had been dried at 60°C for 3 hours, was melt-kneaded using a 26mm twin-screw extruder (TEM26) manufactured by Toshiba Machine Co., Ltd. under conditions of a molding temperature of 160°C, a screw rotation speed of 100 rpm, a discharge rate of 10 kg / hr, and a die diameter of 3 mm to obtain a melt-kneaded product (A) (resin (A)). The melt-kneaded product (A) was taken out of the die in the form of a strand and cut into pellets to obtain pellets (A).

[0115] Separately, a mixture of 29.3 parts by weight of X131A, 70.7 parts by weight of Ecoflex C1200, and 0.200 parts by weight of PBI, which had been dried at 60°C for 3 hours, was melt-kneaded and reacted under the same conditions as above using a 26mm twin-screw extruder (TEM26) manufactured by Toshiba Machine Co., Ltd., to obtain a melt-kneaded product (B) (resin (B)), which is a compatibilized biodegradable resin containing the reaction product. The melt-kneaded product (B) was taken up from the die in the form of a strand and cut into pellets to obtain pellets (B).

[0116] (Preparation of Resin Composition Pellets) A mixture of 86 parts by weight of pellets (A) and 14 parts by weight of pellets (B) dried at 60°C for 3 hours was melt-kneaded under the same conditions as above using a 26 mm twin-screw extruder (TEM26) manufactured by Toshiba Machine Co., Ltd. to obtain a resin composition (aliphatic polyester resin composition). The resin composition was taken out of the die in the form of strands and cut into pellets to obtain pellets (C).

[0117] (injection molding) Pellets (C) dried at 60°C for 3 hours were injection molded using an injection molding machine (Toyo Seiki Kinzoku Co., Ltd.: CH150B) under the following conditions: cylinder temperature H1 = 160°C, H2 = 150°C, H3 = 140°C, nozzle temperature 160°C, mold temperature 45°C, and cooling time 30 seconds to obtain a molded body (80mm x 80mm x 1mm). The molded body was then divided into four 40mm x 40mm x 1mm test pieces, and the 50% fracture energy and dispersed particle size were measured using the methods described above. The results are shown in Table 1.

[0118] Example 2 A resin composition (aliphatic polyester resin composition) and a molded body (test piece) were obtained in the same manner as in Example 1, except that the amount of X131A in the melt-kneaded product (A) was 71 parts by weight, and a mixture of 72 parts by weight of pellets (A) and 28 parts by weight of pellets (B) was melt-kneaded. Then, the 50% fracture energy and dispersed particle size of the obtained molded body were measured by the above-mentioned methods. The results are shown in Table 1.

[0119] Example 3 A resin composition (aliphatic polyester resin composition) and a molded body (test piece) were obtained in the same manner as in Example 1, except that the amount of X131A in the melt-kneaded product (A) was 57 parts by weight, and a mixture of 58 parts by weight of pellets (A) and 42 parts by weight of pellets (B) was melt-kneaded. Then, the 50% fracture energy and dispersed particle size of the obtained molded body were measured by the above-mentioned methods. The results are shown in Table 1.

[0120] Comparative Example 1 (Pellet production) A mixture of 99 parts by weight of X131A and 1 part by weight of PETL, which had been dried at 60°C for 3 hours, was melt-kneaded using a 26mm twin-screw extruder (TEM26) manufactured by Toshiba Machine Co., Ltd. under conditions of a molding temperature of 160°C, a screw rotation speed of 100 rpm, a discharge rate of 10 kg / hr, and a die diameter of 3 mm to obtain a kneaded product. The kneaded product was taken out of the die in the form of a strand and cut into pellets to obtain pellets (resin composition).

[0121] (injection molding) The pellets were dried at 60°C for 3 hours and then injection-molded using an injection molding machine (Toyo Seiki Kinzoku Co., Ltd.: CH150B) under the following conditions: cylinder temperature H1 = 160°C, H2 = 150°C, H3 = 140°C, nozzle temperature 160°C, mold temperature 45°C, and cooling time 30 seconds to obtain a molded body (80mm x 80mm x 1mm). The molded body was then divided into four 40mm x 40mm x 1mm test pieces, and the 50% fracture energy was measured using the method described above. The results are shown in Table 1.

[0122] Comparative Example 2 Pellets (resin composition) and molded bodies (test pieces) were obtained in the same manner as in Comparative Example 1, except that X131A was changed to 151C. Then, the 50% fracture energy of the obtained molded bodies was measured by the above-mentioned method. The results are shown in Table 1.

[0123] Comparative Example 3 (Pellet production) A mixture of 90 parts by weight of X131A, 1 part by weight of PETL, and 10 parts by weight of Ecoflex C1200, which had been dried at 60°C for 3 hours, was melt-kneaded using a 26mm twin-screw extruder (TEM26) manufactured by Toshiba Machine Co., Ltd. under conditions of a molding temperature of 160°C, a screw rotation speed of 100 rpm, a discharge rate of 10 kg / hr, and a die diameter of 3 mm to obtain a kneaded product. The kneaded product was taken out of the die in the form of a strand and cut into pellets to obtain pellets (resin composition).

[0124] (injection molding) The pellets were dried at 60°C for 3 hours and then injection-molded using an injection molding machine (Toyo Seiki Kinzoku Co., Ltd.: CH150B) under the following conditions: cylinder temperature H1 = 160°C, H2 = 150°C, H3 = 140°C, nozzle temperature 160°C, mold temperature 45°C, and cooling time 30 seconds to obtain a molded product (80mm x 80mm x 1mm). The molded product was then divided into four 40mm x 40mm x 1mm test pieces, and the 50% fracture energy and dispersed particle size were measured using the methods described above. The results are shown in Table 1.

[0125] Comparative Example 4 Pellets (resin composition) and molded bodies (test pieces) were obtained in the same manner as in Comparative Example 3, except that the amount of X131A was 80 parts by weight and the amount of Ecoflex C1200 was 20 parts by weight. The 50% fracture energy and dispersed particle size of the obtained molded bodies were then measured using the methods described above. The results are shown in Table 1.

[0126] Comparative Example 5 Pellets (resin composition) and molded articles (test pieces) were obtained in the same manner as in Comparative Example 3, except that the amount of X131A was 70 parts by weight and the amount of Ecoflex C1200 was 30 parts by weight. The 50% fracture energy and dispersed particle size of the obtained molded articles were then measured using the methods described above. The results are shown in Table 1.

[0127] Comparative Example 6 Pellets (resin composition) and molded articles (test pieces) were obtained in the same manner as in Comparative Example 3, except that 0.2 parts by weight of PBI was further added to the mixture in (Pellet Preparation). The 50% fracture energy and dispersed particle size of the obtained molded articles were then measured by the methods described above. The results are shown in Table 1.

[0128] Comparative Example 7 Pellets (resin composition) and molded articles (test pieces) were obtained in the same manner as in Comparative Example 4, except that 0.2 parts by weight of PBI was further added to the mixture in (Pellet Preparation). The 50% fracture energy and dispersed particle size of the obtained molded articles were then measured by the methods described above. The results are shown in Table 1.

[0129] Comparative Example 8 Pellets (resin composition) and molded articles (test pieces) were obtained in the same manner as in Comparative Example 5, except that 0.2 parts by weight of PBI was further added to the mixture in (Pellet Preparation). The 50% fracture energy and dispersed particle size of the obtained molded articles were then measured by the methods described above. The results are shown in Table 1.

[0130] [Table 1] In Table 1, "P3HA content (parts by weight)" and "content of biodegradable resin with glass transition temperature of -10°C or lower (parts by weight)" indicate the proportion of each resin in the resin composition, i.e., the proportion of each resin when the resin composition is taken as 100 parts by weight.

[0131] 〔result〕 As shown in Table 1, a comparison between Examples 1 to 3 and Comparative Examples 1 and 2 reveals that the aliphatic polyester resin composition has excellent impact resistance when it contains a biodegradable resin other than P3HA that has a glass transition temperature of -10°C or lower.

[0132] Furthermore, in Table 1, a comparison of Examples and Comparative Examples (i.e., Example 1 with Comparative Examples 3 and 6, Example 2 with Comparative Examples 4 and 7, and Example 3 with Comparative Examples 5 and 8) in which the content (usage amount) of the biodegradable resin other than P3HA with a glass transition temperature of -10°C or lower in the aliphatic polyester resin composition is the same shows that all Examples have excellent impact resistance. In particular, a comparison of Example 1 with Comparative Example 6, Example 2 with Comparative Example 7, and Example 3 with Comparative Example 8 shows that Examples in which a portion of P3HA was previously melt-kneaded with a biodegradable resin other than P3HA with a glass transition temperature of -10°C or lower and a peroxide to obtain a reaction product, and then the reaction product was melt-kneaded with the remaining P3HA, showed excellent impact resistance.

[0133] Furthermore, from Figure 1 and a comparison of Example 2 with Comparative Examples 5 and 8, it can be seen that in the Example, the dispersed particle size of the compatibilized biodegradable resin is smaller (i.e., the compatibilized biodegradable resin is more finely dispersed).

[0134] The above results indicate that an aliphatic polyester resin composition with excellent impact resistance can be obtained by melt-kneading a portion of the P3HA contained in the aliphatic polyester resin composition with a biodegradable resin other than P3HA that has a glass transition temperature of -10°C or lower and a peroxide to obtain a compatibilized biodegradable resin containing a reaction product, and then melt-kneading the remaining P3HA with the resulting compatibilized biodegradable resin. It was also suggested that such impact resistance is achieved by reducing the dispersed particle size of the compatibilized biodegradable resin in the resin composition. [Industrial Applicability]

[0135] The present invention can provide an aliphatic polyester-based resin composition and a molded article thereof that are biodegradable and have excellent impact resistance, and therefore the composition and molded article can be suitably used in agriculture, fisheries, forestry, horticulture, medicine, hygiene products, the food industry, clothing, non-clothing, packaging, automobiles, building materials, and other fields.

Claims

1. An aliphatic polyester resin composition containing the following (A) and (B): (A) poly(3-hydroxyalkanoate), (B) a compatibilized biodegradable resin containing a reaction product of poly(3-hydroxyalkanoate), a biodegradable resin other than poly(3-hydroxyalkanoate) having a glass transition temperature of −10° C. or lower, and a peroxide; The aliphatic polyester resin composition, wherein the dispersed particle diameter of (B) in the aliphatic polyester resin composition is 0.1 to 1.5 μm.

2. 2. The aliphatic polyester resin composition according to claim 1, wherein the content of (B) is 5 to 50 parts by weight based on 100 parts by weight of the aliphatic polyester resin composition.

3. 3. The aliphatic polyester resin composition according to claim 1, wherein the content of the peroxide is 0.01 to 0.5 parts by weight based on 100 parts by weight of the aliphatic polyester resin composition.

4. The aliphatic polyester resin composition according to any one of claims 1 to 3, wherein the biodegradable resin (B) other than poly(3-hydroxyalkanoate) and having a glass transition temperature of -10°C or lower is at least one selected from the group consisting of polybutylene adipate terephthalate, polybutylene succinate adipate, polybutylene succinate, polybutylene succinate terephthalate, polybutylene succinate adipate terephthalate, polybutylene sebacate terephthalate, polybutylene azelate terephthalate, and polycaprolactone.

5. 5. The aliphatic polyester resin composition according to claim 1, wherein the peroxide is an organic peroxide having a one-minute half-life temperature of 180° C. or less.

6. The aliphatic polyester resin composition according to any one of claims 1 to 5, wherein the peroxide is at least one selected from the group consisting of t-butylperoxyisopropyl monocarbonate, t-pentylperoxyisopropyl monocarbonate, t-hexylperoxyisopropyl monocarbonate, t-butylperoxy 2-ethylhexyl monocarbonate, t-pentylperoxy 2-ethylhexyl monocarbonate, and t-hexylperoxy 2-ethylhexyl monocarbonate.

7. The aliphatic polyester resin composition according to any one of claims 1 to 6, further comprising a crystal nucleating agent and / or a lubricant.

8. The aliphatic polyester resin composition according to any one of claims 1 to 7, wherein the compatibilized biodegradable resin is obtained by melt-kneading the poly(3-hydroxyalkanoate), a biodegradable resin other than the poly(3-hydroxyalkanoate) having a glass transition temperature of -10°C or lower, and the peroxide.

9. The aliphatic polyester resin composition according to any one of claims 1 to 8, wherein the aliphatic polyester resin composition is obtained by melt-kneading the (A) and the (B).

10. A molded article comprising the aliphatic polyester resin composition according to any one of claims 1 to 9.

11. (a) melt-kneading poly(3-hydroxyalkanoate), a biodegradable resin other than poly(3-hydroxyalkanoate) having a glass transition temperature of −10° C. or lower, and a peroxide to obtain a compatibilized biodegradable resin; (b) A step of melt-kneading the compatibilized biodegradable resin obtained in the step (a) with poly(3-hydroxyalkanoate) to obtain an aliphatic polyester resin composition. A method for producing an aliphatic polyester resin composition, comprising:

12. The method according to claim 11, wherein the amount of the compatibilizing biodegradable resin in the step (b) is 5 to 50 parts by weight based on 100 parts by weight of the aliphatic polyester resin composition.

13. 13. The method according to claim 11, wherein the amount of the peroxide in the step (a) is 0.01 to 0.5 parts by weight based on 100 parts by weight of the aliphatic polyester resin composition.

14. The method according to any one of claims 11 to 13, wherein the biodegradable resin other than poly(3-hydroxyalkanoate) and having a glass transition temperature of -10°C or lower in step (a) is at least one selected from the group consisting of polybutylene adipate terephthalate, polybutylene succinate adipate, polybutylene succinate, polybutylene succinate terephthalate, polybutylene succinate adipate terephthalate, polybutylene sebacate terephthalate, polybutylene azelate terephthalate, and polycaprolactone.

15. The method according to any one of claims 11 to 14, wherein the peroxide in step (a) is an organic peroxide having a one-minute half-life temperature of 180°C or lower.

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