Resin composition

Abstract

This resin composition comprises a polyhydroxyalkanoic acid-based polymer [including any one of: (1) a first monomeric unit represented by formula (M1); (2) a first monomeric unit represented by formula (M1) and a second monomeric unit represented by formula (M2) (where R1 are defined in the description); (3) a first monomeric unit represented by formula (M1) and a third monomeric unit represented by formula (M3); and (4) a first monomeric unit represented by formula (M1), a second monomeric unit represented by formula (M2), and a third monomeric unit represented by formula (M3)]. This resin composition also comprises a polyester-based polymer [including a monomeric unit having a diol component and a dicarboxylic acid component. At least a portion of the end of the polyester-based polymer is sealed with a residue of a monoalcohol and / or a residue of a monocarboxylic acid].

Description

resin composition

[0001] The present invention relates to a resin composition.

[0002] In recent years, due to the demand for environmentally friendly, sustainable biomass resins and biodegradable resins, active development of these resins has been underway. In this context, polyhydroxyalkanoic acid polymers, which are biomass and biodegradable resins, are used in a wide range of fields, including packaging, food service, biomedical applications, and agriculture. However, polyhydroxyalkanoic acid polymers are generally known to be more brittle than petroleum-based resins and to have inferior flexibility (elongation) and impact resistance. Therefore, the use of polyhydroxyalkanoic acid polymers as resin materials is sometimes limited. In this context, attempts to improve the physical properties of biomass resins and biodegradable resins have been made, for example, to impart flexibility while suppressing bleed-out (see, for example, Patent Documents 1 and 2).

[0003] JP 2005-023091 A International Publication No. 2023 / 026758

[0004] However, Patent Documents 1 and 2 only mainly consider polylactic acid polymers as biomass resins and biodegradable resins, including the examples, and do not specifically or sufficiently consider polyhydroxyalkanoic acid polymers from the viewpoint of imparting bleed resistance and flexibility, etc.

[0005] In view of the above, an object of the present invention is to provide a resin composition that has good elongation and impact resistance while maintaining biodegradability and bleed-out resistance.

[0006] As a result of intensive research to solve the above problems, the present inventors have conceived the following invention and found that the above problems can be solved.

[0007] [1] A resin composition comprising a polyhydroxyalkanoic acid polymer and a polyester polymer, wherein the polyhydroxyalkanoic acid polymer comprises a monomer unit selected from any one of the following (1) to (4): (1) a first monomer unit represented by formula (M1); (2) a first monomer unit represented by formula (M1) and a second monomer unit represented by formula (M2); (3) a first monomer unit represented by formula (M1) and a third monomer unit represented by formula (M3); (4) a first monomer unit represented by formula (M1), a second monomer unit represented by formula (M2), and a third monomer unit represented by formula (M3); wherein the formulas (M1), (M2), and (M3) are represented by the following: (In formula (M2), R １is a hydrogen atom or an alkyl group having 2 to 4 carbon atoms.) The polyester polymer comprises a monomer unit having a diol component and a dicarboxylic acid component, wherein the diol of the diol component is a branched aliphatic alkylene diol having a total of 3 to 12 carbon atoms, and the dicarboxylic acid of the dicarboxylic acid component is an aliphatic dicarboxylic acid having 4 to 14 carbon atoms, an alicyclic dicarboxylic acid having 5 to 14 carbon atoms, or an aromatic dicarboxylic acid having 6 to 14 carbon atoms, and at least a portion of the ends of the polyester polymer are blocked with a residue of a monoalcohol and / or a residue of a monocarboxylic acid, and the monoalcohols are each independently an aliphatic monoalcohol having 1 to 10 carbon atoms, an alicyclic monoalcohol having 5 to 12 carbon atoms, or an aromatic monoalcohol having 6 to 12 carbon atoms, and the monocarboxylic acids are each independently an aliphatic monocarboxylic acid having 1 to 10 carbon atoms, or an aromatic monocarboxylic acid having 6 to 12 carbon atoms. [2] The resin composition according to [1] above, comprising 5 to 40 parts by mass of the polyester polymer per 100 parts by mass of the polyhydroxyalkanoic acid polymer. [3] The resin composition according to [1] above, wherein the molar ratio of the first monomer unit to the total molar amount of the first monomer unit, the second monomer unit, and the third monomer unit contained in the polyhydroxyalkanoic acid polymer is 0.20 to 1.00, the molar ratio of the second monomer unit to the total molar amount of the second monomer unit to the total molar amount of the third monomer unit to the total molar amount of the third monomer unit to the total molar amount of the first ... [5] The resin composition according to any one of [1] to [4] above, wherein the polyester polymer further contains a monomer unit composed of a trihydric or higher polyhydric alcohol component, and the polyhydric alcohol of the trihydric or higher polyhydric alcohol component is an aliphatic alkylene polyol having a branched chain and a total of 3 to 12 carbon atoms.[6] The resin composition according to [5] above, wherein the ratio of the molar amount of the diol to the total molar amount of the diol and the trihydric or higher polyhydric alcohol contained in the polyester polymer is 0.20 or more and less than 1.00, and the ratio of the molar amount of the trihydric or higher polyhydric alcohol to the total molar amount of the diol and the trihydric or higher polyhydric alcohol is more than 0 and 0.80 or less. [7] The resin composition according to any of [1] to [6] above, wherein the polyester polymer has a hydroxyl value of 150 mg KOH / g or less and an acid value of 50 mg KOH / g or less. [8] The resin composition according to any of [1] to [7] above, wherein the polyester polymer has a number average molecular weight of 200 to 10,000. [9] The resin composition according to any of [1] to [8] above, wherein the dicarboxylic acid in the polyester polymer is an aliphatic dicarboxylic acid having 4 to 10 carbon atoms and a methylene group.

[10] The resin composition according to any one of [1] to [9] above, wherein in the polyester polymer, the diol is a branched aliphatic alkylenediol having a total of 4 to 10 carbon atoms.

[11] The resin composition according to any one of [5] to

[10] above, wherein in the polyester polymer, the polyhydric alcohol of the trihydric or higher polyhydric alcohol component is a branched alkylene triol having a total of 3 to 6 carbon atoms.

[12] The resin composition according to any one of [9] to

[11] above, wherein in the polyester polymer, the aliphatic dicarboxylic acid having a methylene group having 4 to 10 carbon atoms is adipic acid or sebacic acid.

[13] The resin composition according to any one of

[10] to

[12] above, wherein in the polyester polymer, the branched aliphatic alkylenediol having a total of 4 to 10 carbon atoms is MPD (3-methyl-1,5-pentanediol) or MOD (2-methyl-1,8-octanediol).

[14] The resin composition according to any one of the above

[11] to

[13] , wherein the branched alkylene triol having a total carbon number of 3 to 6 is trimethylolpropane.

[15] The resin composition according to any one of the above [1] to

[14] , wherein in the polyester-based polymer, the monoalcohol is 2-ethylhexanol.

[16] The resin composition according to any one of the above [1] to

[15] , wherein in the polyester-based polymer, the monocarboxylic acid is acetic acid.

[17] A molded article made of the resin composition according to any one of [1] to

[16] above.

[18] A molded article made of the resin composition according to any one of [5] to

[16] above.

[0008] According to the present invention, it is possible to provide a resin composition that has good elongation and impact resistance while maintaining biodegradability and bleed-out resistance.

[0009] The following describes an embodiment of the present invention. However, the embodiment described below is merely an example for embodying the technical concept of the present invention, and the present invention is not limited to the following description. Although preferred embodiments are shown in this specification, combinations of two or more of the individual preferred embodiments are also preferred. For matters indicated as numerical ranges, when there are several numerical ranges, the lower and upper limits can be selectively combined to create a preferred embodiment. Furthermore, when a numerical range is described as "XX to YY," it means "XX or more and YY or less." In this specification, "~ unit" (where "~" indicates a polymer) means "a structural unit derived from ~." For example, "monomer unit" means "a structural unit derived from a monomer." In this specification, "main chain" refers to the longest molecular chain in a molecule, a molecular chain with hydroxyl groups attached to both ends. Furthermore, "branched chain" refers to a molecular chain other than the main chain in a molecule, unless otherwise specified.

[0010] [Resin Composition] The resin composition of this embodiment contains a polyhydroxyalkanoic acid polymer and a polyester polymer. The polyhydroxyalkanoic acid polymer contains a monomer unit selected from any one of the following (1) to (4): (1) a first monomer unit represented by formula (M1); (2) a first monomer unit represented by formula (M1) and a second monomer unit represented by formula (M2); (3) a first monomer unit represented by formula (M1) and a third monomer unit represented by formula (M3); (4) a first monomer unit represented by formula (M1), a second monomer unit represented by formula (M2), and a third monomer unit represented by formula (M3). The formulas (M1), (M2), and (M3) are represented as follows: (In formula (M2), R １ is a hydrogen atom or an alkyl group having 2 to 4 carbon atoms.) The polyester polymer also contains a monomer unit having a diol component and a dicarboxylic acid component, and at least a portion of the terminals of the monomer unit are terminated with a residue of a monoalcohol and / or a residue of a monocarboxylic acid. The diol of the diol component is a branched aliphatic alkylene diol having a total of 3 to 12 carbon atoms, and the dicarboxylic acid of the dicarboxylic acid component is an aliphatic dicarboxylic acid having 4 to 14 carbon atoms, an alicyclic dicarboxylic acid having 5 to 14 carbon atoms, or an aromatic dicarboxylic acid having 6 to 14 carbon atoms. The monoalcohols are each independently an aliphatic monoalcohol having 1 to 10 carbon atoms, an alicyclic monoalcohol having 5 to 12 carbon atoms, or an aromatic monoalcohol having 6 to 12 carbon atoms, and the monocarboxylic acids are each independently an aliphatic monocarboxylic acid having 1 to 10 carbon atoms, or an aromatic monocarboxylic acid having 6 to 12 carbon atoms. As a result of extensive investigations, the present inventors have found that a resin composition containing a specific polyhydroxyalkanoic acid polymer and a specific polyester polymer has good elongation and impact resistance while maintaining biodegradability and resistance to bleeding out.

[0011] The reason why the resin composition of this embodiment has good elongation and impact resistance is not clear, but is presumed to be as follows. Because the polyester polymer contains an ester structure, it is likely to have a moderate compatibility with the polyhydroxyalkanoic acid polymer, which also contains an ester structure. Furthermore, by ester-modifying the terminal hydroxyl groups of the amorphous, flexible polyester polymer, which has a low glass transition temperature Tg, it is thought that compatibility with the polyhydroxyalkanoic acid polymer is further improved, resulting in improved elongation and impact resistance. The glass transition temperature Tg of the polyester polymer is preferably −40° C. or lower, more preferably −50° C. or lower, and even more preferably −60° C. or lower.

[0012] <Polyhydroxyalkanoic acid polymer> The polyhydroxyalkanoic acid polymer used in this embodiment contains a monomer unit selected from any one of the following (1) to (4): (1) a first monomer unit represented by formula (M1); (2) a first monomer unit represented by formula (M1) and a second monomer unit represented by formula (M2); (3) a first monomer unit represented by formula (M1) and a third monomer unit represented by formula (M3); (4) a first monomer unit represented by formula (M1), a second monomer unit represented by formula (M2), and a third monomer unit represented by formula (M3).

[0013] The formula (M1), the formula (M2), and the formula (M3) are represented as follows. (In formula (M2), R １ is a hydrogen atom or an alkyl group having 2 to 4 carbon atoms. １ Examples of the alkyl group having 2 to 4 carbon atoms represented by include an ethyl group, an isopropyl group, an n-butyl group, a tert-butyl group, etc., and preferred are an ethyl group and a tert-butyl group.

[0014] It is preferable that the ratio of the molar amount of the first monomer unit to the total amount of the first monomer unit, the molar amount of the second monomer unit, and the molar amount of the third monomer unit contained in the polyhydroxyalkanoic acid polymer is 0.20 to 1.00, the ratio of the molar amount of the second monomer unit to the total amount of the second monomer unit, and the ratio of the molar amount of the third monomer unit to the total amount of the third monomer unit are 0 to 0.80, and more preferably the ratio of the molar amount of the first monomer unit to the total amount of the second monomer unit is 0 to 0.50, and the ratio of the molar amount of the third monomer unit is 0 to 0.50.

[0015] From the viewpoints of elongation and impact resistance, the weight-average molecular weight of the polyhydroxyalkanoic acid polymer is preferably 50,000 or more, more preferably 100,000 or more, and even more preferably 150,000 or more. From the viewpoints of moldability and compatibility with polyester polymers, it is preferably 3,000,000 or less, more preferably 2,000,000 or less, and even more preferably 1,000,000 or less. That is, the weight-average molecular weight of the polyhydroxyalkanoic acid polymer is preferably 50,000 to 3,000,000, more preferably 100,000 to 2,000,000, and even more preferably 150,000 to 1,000,000. The weight-average molecular weight of the polyhydroxyalkanoic acid polymer can be determined in terms of standard polystyrene by gel permeation chromatography (GPC). When using a commercially available product, the catalog value may be used.

[0016] Commercially available polyhydroxyalkanoic acid polymers may be used, such as those available under the trade name "Poly(3-hydroxybutyric acid) natural origin, average Mn: 500,000" (manufactured by Aldrich), those available under the trade name "Poly(3-hydroxybutyric acid-co-3-hydroxyvaleric acid) natural origin, PHV content: 8 mol%" (manufactured by Aldrich), and those available under the trade name "EM5400A" (manufactured by Ecomann).

[0017] The polyhydroxyalkanoic acid polymer may be a copolymer of a first monomer unit represented by formula (M1), a second monomer unit represented by formula (M2), and a third monomer unit represented by formula (M3) and other monomer units. The copolymer preferably contains 70 mol% or more, more preferably 80 mol% or more, even more preferably 90 mol% or more, and particularly preferably 95 mol% or more, and may contain 100 mol% of units derived from hydroxyalkanoic acid. The upper limit of the amount of units derived from hydroxyalkanoic acid contained in the copolymer is not limited, and may be, for example, 100 mol% or less. The total content of the first monomer unit represented by formula (M1), the second monomer unit represented by formula (M2), and the third monomer unit represented by formula (M3) in 100 mol% of the total amount of monomer units constituting the polyhydroxyalkanoic acid polymer is preferably 80 to 100 mol%, more preferably 90 to 100 mol%, even more preferably 99 to 100 mol%, and may be 100 mol%.

[0018] <Polyester-Based Polymer> The polyester-based polymer contains a monomer unit having a diol component and a dicarboxylic acid component, and some of the terminals of the monomer unit are capped with a monoalcohol residue and / or a monocarboxylic acid residue.

[0019] The diol of the diol component is an aliphatic alkylenediol having a total of 3 to 12 carbon atoms and having an alkyl group as a branched chain. The "branched chain" in the aliphatic alkylenediol refers to a partial structure branched from the "main chain" of the aliphatic alkylenediol, and no hydroxyl group is bonded to its terminal. The "total number of carbon atoms" mentioned above is the total number of carbon atoms in the aliphatic alkylenediol, including the number of carbon atoms constituting the alkyl group. When the diol contains an aliphatic alkylenediol having 4 or more carbon atoms and having an alkyl group as a branched chain, the polyester polymer becomes flexible, and the resin composition exhibits excellent elongation and impact resistance.

[0020] In the aliphatic alkylenediol, the number of branched chains is preferably 1, 2, or 3, more preferably 1 or 2, and even more preferably 1. The branched chains are preferably methyl groups, ethyl groups, and propyl groups, more preferably methyl groups and ethyl groups, and even more preferably methyl groups. When the aliphatic alkylenediol has multiple branched chains, the respective branched chains may be the same or different.

[0021] From the viewpoint of easy reaction with dicarboxylic acid and easy production, and from the viewpoint of even better biodegradability, the aliphatic alkylene diol preferably has hydroxyl groups at both ends of the main chain.

[0022] Examples of aliphatic alkylenediols having a branched chain and a total carbon number of 3 to 12 include 2-methyl-1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 2,2-dimethyl-1,3-propanediol, 2-ethyl-1,3-propanediol, 2-ethyl-2-methyl-1,3-propanediol, 2-methyl-1,4-butanediol, 1,1-dimethyl-1,3-butanediol, 1,2-pentanediol, 1,3-pentanediol, 2,3-pentanediol, 2,4-pentanediol, 2- Examples of suitable diols include methyl-2,4-pentanediol, 1,4-pentanediol, 2-methyl-1,5-pentanediol, 3-methyl-1,5-pentanediol (MPD), 2-ethyl-1,5-pentanediol, 2,4-dimethyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol, 1,2-hexanediol, 1,3-hexanediol, 1,4-hexanediol, 1,5-hexanediol, 2-ethyl-1,6-hexanediol, and 2-methyl-1,8-octanediol (MOD). In the polyester polymer, the diol is preferably an aliphatic alkylene diol having a branched chain and a total of 4 to 10 carbon atoms. The branched aliphatic alkylenediol having a total of 4 to 10 carbon atoms is preferably MPD (3-methyl-1,5-pentanediol) or MOD (2-methyl-1,8-octanediol).

[0023] From the viewpoint of biodegradability, the total number of carbon atoms in the aliphatic alkylenediol is preferably 10 or less, more preferably 9 or less.

[0024] The dicarboxylic acid of the dicarboxylic acid component is an aliphatic dicarboxylic acid having 4 to 14 carbon atoms, an alicyclic dicarboxylic acid having 5 to 14 carbon atoms, or an aromatic dicarboxylic acid having 6 to 14 carbon atoms.

[0025] Examples of aliphatic dicarboxylic acids having 4 to 14 carbon atoms include succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, decanedicarboxylic acid, dodecylsuccinic acid, dodecenylsuccinic acid, octenylsuccinic acid, etc. One type of aliphatic dicarboxylic acid may be used alone, or two or more types may be used in combination.

[0026] In the polyester polymer, the dicarboxylic acid is preferably an aliphatic dicarboxylic acid having a methylene group and having 4 to 10 carbon atoms. From the viewpoint of exhibiting good elongation and impact resistance, the aliphatic dicarboxylic acid is preferably at least one selected from adipic acid and sebacic acid.

[0027] Examples of the alicyclic dicarboxylic acid having 5 to 14 carbon atoms include 1,3-cyclobutanedicarboxylic acid, 1,2-cyclopentanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, and 1,4-cyclohexanedicarboxylic acid.

[0028] Examples of aromatic dicarboxylic acids having 6 to 14 carbon atoms include phthalic acid, terephthalic acid, isophthalic acid, diphenic acid, 4,4'-biphenyldicarboxylic acid, diphenylmethane-4,4'-dicarboxylic acid, diphenylsulfone-4,4'-dicarboxylic acid, 1,2-naphthalenedicarboxylic acid, 1,3-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 1,6-naphthalenedicarboxylic acid, 1,7-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 2,3-furandicarboxylic acid, 2,4-furandicarboxylic acid, 2,5-furandicarboxylic acid, and 3,4-furandicarboxylic acid. From the viewpoint of exhibiting good elongation and impact resistance, the aromatic dicarboxylic acid is preferably at least one selected from terephthalic acid and isophthalic acid. Aromatic dicarboxylic acids may be used alone or in combination of two or more. From the viewpoint of biodegradability, the content of units derived from aliphatic dicarboxylic acids having 4 to 14 carbon atoms in a total of 100 mol % of units derived from dicarboxylic acids and trivalent or higher polycarboxylic acids constituting the polyester polymer is preferably 30 to 100 mol %, more preferably 50 to 100 mol %, and even more preferably 90 to 100 mol %. From the viewpoint of biodegradability, the content of aromatic dicarboxylic acids in the dicarboxylic acid component is preferably 90 mol % or less, more preferably 70 mol % or less, and even more preferably 50 mol % or less.

[0029] In a preferred embodiment, from the viewpoint of exhibiting even better biodegradability, the diol of the diol component is selected from 3-methyl-1,5-pentanediol, 2-methyl-1,3-propanediol, or 2-methyl-1,8-octanediol, and the dicarboxylic acid of the dicarboxylic acid component is selected from succinic acid, adipic acid, or sebacic acid. More preferred embodiments include a combination of 3-methyl-1,5-pentanediol and adipic acid, and a combination of 3-methyl-1,5-pentanediol and sebacic acid.

[0030] The monoalcohols are each independently an aliphatic monoalcohol having 1 to 10 carbon atoms, an alicyclic monoalcohol having 5 to 12 carbon atoms, or an aromatic monoalcohol having 6 to 12 carbon atoms.

[0031] Examples of aliphatic monoalcohols having 1 to 10 carbon atoms include methanol, ethanol, 1-propanol, isopropanol, 1-butanol, isobutanol, tert-butanol, 1-pentanol, isopentanol, 1-hexanol, 4-methyl-2-pentanol, 1-heptanol, 1-octanol, isooctanol, 2-ethylhexanol, 1-nonanol, isononanol, and 1-decanol. Examples of alicyclic monoalcohols having 5 to 12 carbon atoms include cyclohexanol, cyclopentanol, and tetrahydrofurfuryl alcohol. Examples of aromatic monoalcohols having 6 to 12 carbon atoms include benzyl alcohol and 3-phenyl-1-propanol. These may be used alone or in combination of two or more. Of these, 2-ethylhexanol is preferred as the monoalcohol.

[0032] The monocarboxylic acids are each independently an aliphatic monocarboxylic acid having 1 to 10 carbon atoms or an aromatic monocarboxylic acid having 6 to 12 carbon atoms. Examples of aliphatic monocarboxylic acids having 1 to 10 carbon atoms include acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, and derivatives thereof. Examples of aromatic monocarboxylic acids having 6 to 12 carbon atoms include benzoic acid, toluic acid, α-naphthalenecarboxylic acid, β-naphthalenecarboxylic acid, methylnaphthalenecarboxylic acid, phenylacetic acid, and derivatives thereof. These may be used alone or in combination of two or more. Of these, acetic acid is preferred as the monocarboxylic acid.

[0033] In one embodiment, the polyester polymer further comprises a monomer unit having a trihydric or higher polyhydric alcohol component and a dicarboxylic acid component, and the terminals of the monomer unit are preferably terminated with a residue of the monoalcohol and / or a residue of the monocarboxylic acid. The polyhydric alcohol of the trihydric or higher polyhydric alcohol component is preferably an aliphatic alkylene polyol having a branched chain and a total of 3 to 12 carbon atoms.

[0034] Examples of the aliphatic alkylene polyol having a branched chain and a total carbon number of 3 to 12 include aliphatic triols such as glycerin, butanetriol, trimethylolethane, triethylolethane, and trimethylolpropane; aliphatic tetraols such as pentaerythritol; aliphatic pentaols such as arabinitol and xylitol; and aliphatic hexaols such as sorbitol, mannitol, iditol, and dipentaerythritol. In the polyester polymer, it is preferable that the aliphatic alkylene polyol is an aliphatic alkylene triol, and that the aliphatic alkylene triol is a branched alkylene triol having a total carbon number of 3 to 6. It is preferable that the branched alkylene triol having a total carbon number of 3 to 6 is trimethylolpropane.

[0035] In a preferred embodiment, from the viewpoint of exhibiting even better biodegradability, the polyhydric alcohol of the polyhydric alcohol component is selected from glycerol, trimethylolpropane, or pentaerythritol, and the dicarboxylic acid of the dicarboxylic acid component is selected from succinic acid, adipic acid, or sebacic acid. More preferred embodiments include a combination of trimethylolpropane and adipic acid, and a combination of trimethylolpropane and sebacic acid.

[0036] In a preferred embodiment, from the viewpoint of exhibiting even better biodegradability, the above-mentioned preferred monomer units containing a diol component and a dicarboxylic acid component and the above-mentioned preferred monomer units containing a trihydric or higher polyhydric alcohol component and a dicarboxylic acid component coexist in the polyester polymer. Specifically, a combination of 3-methyl-1,5-pentanediol as the diol component, adipic acid as the dicarboxylic acid component, and trimethylolpropane as the trihydric or higher polyhydric alcohol component, and a combination of 3-methyl-1,5-pentanediol as the diol component, sebacic acid as the dicarboxylic acid component, and trimethylolpropane as the trihydric or higher polyhydric alcohol component are preferred examples of the embodiment.

[0037] The ratio of the molar amount of the diol to the total amount of the molar amount of the diol and the molar amount of the trihydric or higher polyhydric alcohol contained in the polyester polymer is preferably 0.20 or more and less than 1.00, and the ratio of the molar amount of the trihydric or higher polyhydric alcohol is more preferably more than 0 and 0.80 or less, more preferably 0.50 or more and less than 1.00, and the ratio of the molar amount of the trihydric or higher polyhydric alcohol is more than 0 and 0.50 or less, and even more preferably 0.70 or more and less than 1.00, and the ratio of the molar amount of the trihydric or higher polyhydric alcohol is more than 0 and 0.30 or less.

[0038] From the viewpoint of storage stability, the acid value of the polyester polymer is preferably 50 mgKOH / g or less, more preferably 10 mgKOH / g or less, and even more preferably 5 mgKOH / g or less. The acid value of the polyester polymer is measured according to JIS K1557-1:2007. From the viewpoint of compatibility, the hydroxyl value of the polyester polymer is preferably 150 mgKOH / g or less, more preferably 100 mgKOH / g or less, and even more preferably 50 mgKOH / g or less. The hydroxyl value of the polyester polymer is measured according to JIS K1557-1:2007.

[0039] From the viewpoint of achieving both storage stability and compatibility, the acid value and hydroxyl value of the polyester polymer are preferably 50 mgKOH / g or less and 150 mgKOH / g or less, more preferably 10 mgKOH / g or less and 100 mgKOH / g or less, and even more preferably 5 mgKOH / g or less and 50 mgKOH / g or less.

[0040] The polyester polymer may contain a monomer unit (a) other than the monomer units derived from the diol component, the dicarboxylic acid component, and the trihydric or higher polyhydric alcohol component. The monomer unit (a) is not particularly limited as long as it does not impair the effects of the present invention, but the content of the monomer unit (a) in the polyester polymer is preferably 50 mol% or less, more preferably 30 mol% or less, even more preferably 20 mol% or less, still more preferably 15 mol% or less, and particularly preferably 10 mol% or less.

[0041] <Number Average Molecular Weight of Polyester Polymer> From the viewpoints of elongation and impact resistance, the number average molecular weight of the polyester polymer is preferably 200 or more, more preferably 500 or more, and even more preferably 1,000 or more. From the viewpoints of moldability and compatibility with the polyhydroxyalkanoic acid polymer, it is preferably 10,000 or less, more preferably 9,000 or less, and even more preferably 8,000 or less. In one aspect of the present invention, the number average molecular weight of the polyester polymer is preferably 200 to 10,000, more preferably 500 to 10,000, even more preferably 1,000 to 10,000, even more preferably 1,000 to 9,000, and even more preferably 1,000 to 8,000. The number average molecular weight of the polyester polymer can be determined in terms of standard polystyrene by gel permeation chromatography (GPC). When using a commercially available product, the catalog value may be used.

[0042] The resin composition of this embodiment preferably contains 5 to 40 parts by mass, more preferably 6 to 35 parts by mass, even more preferably 7 to 30 parts by mass, and even more preferably 8 to 25 parts by mass of polyester polymer per 100 parts by mass of polyhydroxyalkanoic acid polymer. If the content is within this range, a resin composition with even better elongation and impact resistance can be obtained.

[0043] The total content of the polyhydroxyalkanoic acid polymer and the polyester polymer in the resin composition of this embodiment is 50% by mass or more, preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, still more preferably 95% by mass or more, still more preferably 98% by mass or more, and may be 100% by mass. At this content, the effects of the present invention are more significantly exhibited.

[0044] The resin composition of this embodiment may contain at least one resin component selected from the group consisting of biomass resins and biodegradable resins other than the polyhydroxyalkanoic acid polymer and the polyester polymer. Examples of such biomass resins or biodegradable resins include polycaprolactone (PCL), polybutylene succinate (PBS), polybutylene succinate adipate (PBSA), polybutylene adipate terephthalate (PBAT), polyglycolic acid (PGA), polyethylene furanoate (PEF), cellulose acetate (CA), and starch polyester (Mater-Bi (registered trademark)).

[0045] <Additives> The resin composition of this embodiment may contain additives other than the polyhydroxyalkanoic acid polymer and the polyester polymer. Examples of additives include natural fibers such as cellulose nanofibers and straw, inorganic fillers, softeners, heat aging inhibitors, antioxidants, hydrolysis resistance inhibitors, light stabilizers, antistatic agents, release agents, flame retardants, foaming agents, pigments, dyes, brighteners, UV absorbers, lubricants, and impact modifiers. These may be used alone or in combination of two or more. When using the above additives, the content of the additives in the resin composition may be determined appropriately depending on the desired physical properties of the resin composition.

[0046] <Method for Producing Resin Composition> The method for producing the resin composition of this embodiment is not particularly limited, and the resin composition can be produced, for example, by uniformly mixing a polyhydroxyalkanoic acid polymer, a polyester polymer, and, if necessary, additives. Examples of mixing methods include melt-kneading using a single-screw extruder, a multi-screw extruder, a Banbury mixer, a heated roll, a Brabender, various kneaders, etc., or melt-kneading by feeding each component through a separate inlet. Pre-blending may also be performed before melt-kneading. Examples of pre-blending methods include using a mixer such as a Henschel mixer, a high-speed mixer, a V-blender, a ribbon blender, a tumbler blender, or a conical blender. The temperature during melt-kneading can be selected arbitrarily, preferably within the range of 140 to 220°C, taking into account the melting point and decomposition temperature of the polyester polymer.

[0047] [Molded Article] The present invention provides a molded article made from a resin composition. The shape of the molded article may be any molded article that can be produced using the resin composition of this embodiment, and examples of the molded article include molded articles in various shapes such as pellets, films, sheets, plates, pipes, tubes, bottles, fibers, rods, fine particles, particles, and foams. The method for producing these molded articles is not particularly limited, and they can be molded by known molding methods such as injection molding, blow molding, press molding, extrusion molding, calendar molding, and molding using a 3D printer.

[0048] [Uses] By mixing a polyhydroxyalkanoic acid polymer with a polyester polymer to form a resin composition, it is possible to improve elongation and impact resistance while maintaining biodegradability and bleed-out resistance. Therefore, the present invention provides a modifier for polyhydroxyalkanoic acid polymers, which is made of a polyester polymer. In addition, a preferred embodiment is the use of a polyester polymer as a modifier for polyhydroxyalkanoic acid polymers.

[0049] The resin composition of this embodiment can be used in various applications. Applications of the resin composition include: food utensils such as food bags, food caps, food trays, straws, cutlery, and food containers; stoppers and cap liners for containers storing food, beverages, medicines, and the like; single-layer or multi-layer films and sheets for electronic component packaging, pharmaceutical packaging, food packaging, agricultural materials, civil engineering and construction materials, industrial materials, and the like; fibers such as woven fabrics and nonwoven fabrics; adhesives and bonding agents such as solvent-based, hot-melt-based, and heat-stretched types; coating agents such as aqueous-based, solution-based, emulsion-based, and dispersion-based types; filaments for 3D printers; developing toners; support materials for hydraulic fracturing and agents for preventing water leakage during excavation; various vibration-isolating and vibration-damping materials such as vibration-isolating rubber, mats, sheets, cushions, dampers, pads, and mounting rubber; components for home appliances such as televisions, stereos, vacuum cleaners, refrigerators, and housings for mobile phones; Automobile interior and exterior parts such as bumper parts, body panels, weather strips, grommets, instrument panel coverings, airbag covers, etc.; various grips such as scissors, screwdrivers, toothbrushes, ski poles, etc.; etc.

[0050] The present invention will be specifically explained below with reference to examples and comparative examples, but the present invention is not limited to these.

[0051] [Measurement and Evaluation Methods] Various physical properties were measured or evaluated by the following methods.

[0052] <Number Average Molecular Weight of Polyester Polymer> The polyester polymers (A-1) to (A-8) obtained in the Production Examples were used as samples, and the number average molecular weight (Mn) was determined by gel permeation chromatography (GPC) in terms of molecular weight in terms of standard polystyrene. The specific measurement method is as follows. A tetrahydrofuran (THF) solution was used as the eluent. 10 mg of the sample, calculated as resin, was weighed out and dissolved in 1 mL of the eluent. The solution was passed through a 0.2 μm membrane filter to prepare a measurement sample. The measurement conditions were as follows. (Measurement Conditions) Apparatus: HLC-EcoSEC8320GPC (manufactured by Tosoh Corporation) Column: Three columns, KF-803, KF-802.5, and KF-802 (manufactured by Showa Denko K.K.), were connected in series. Eluent: tetrahydrofuran Flow rate: 0.9 mL / min Sample injection volume: 30 μL Column temperature: 40° C. Standard polystyrene: PSt Oligomer Kit (molecular weight 589 to 98,900) manufactured by Tosoh Corporation was used and approximated by a quintic equation. Detector: RI detector

[0053] <Weight-average molecular weight of polyhydroxyalkanoic acid polymer> The weight-average molecular weight (Mw) of the polyhydroxyalkanoic acid polymer was determined by gel permeation chromatography (GPC) in terms of standard polystyrene. The specific measurement method is as follows. (Measurement conditions) Apparatus: High-performance liquid chromatograph LC-20A (Shimadzu Corporation) Column: K-G 4A (1 column) and K-806M (2 columns) (Showa Denko K.K.) connected in series. Eluent: Chloroform Flow rate: 1.0 mL / min Sample injection amount: 100 μL Column temperature: 40°C Standard polystyrene: Polystyrene standard (molecular weight: 2,880 to 6,570,000) manufactured by Agilent Technologies Inc. was used for quintic approximation. Detector: RI detector

[0054] <Hydroxyl Value and Acid Value of Polyester Polymer> The hydroxyl value and acid value were measured by indicator titration according to Method A of JIS K 1557-1:2007.

[0055] <Impact Resistance Test> (1) Preparation of Test Pieces for Impact Resistance Tests The resin compositions obtained in the examples and comparative examples were subjected to a reduced pressure hot press (Imoto Machinery Co., Ltd. "IMC-183B"), and the pressure was reduced to -0.1 MPaG using an oil rotary pump. The resin compositions were preheated for 5 minutes at a predetermined temperature (190 ° C. for Examples 1 to 14 and Comparative Examples 1 to 3, 200 ° C. for Examples 15 to 28 and Comparative Examples 4 to 6, and 150 ° C. for Examples 29 to 42 and Comparative Examples 7 to 9). Then, the resin compositions were pressed for 3 minutes at 8 MPa using a cooling press equipped with water flow cooling to prepare a 1.0 mm thick press plate. A 50 × 50 mm square piece was cut out from the obtained press plate to prepare a test piece. (2) Measurement of Impact Resistance The above test specimens were stored for 10 hours or more in a low-temperature constant temperature bath (ETAC Corporation's "HIFLEX FL714C") adjusted to the test temperatures shown in Tables 2-1, 2-2, and 2-3 (23°C, 0°C, -15°C, in that order) to condition the humidity. The test specimens after humidity conditioning were measured using a DuPont impact resistance tester (manufactured by Taiyu Kizai Co., Ltd.) according to the following procedures (a) to (d) to evaluate their impact resistance. (a) Using a support rod, a 1 kg weight was set 0.5 m from the support base. (b) The test specimen was removed from the constant temperature bath to an environment of 23°C and 49% relative humidity, and the test specimen was placed between the support base and the hammer. (c) The pressure rod was pulled out, and the weight was dropped toward the hammer. Here, the period from removing the test specimen in (b) to dropping the weight in (c) was 5 seconds or less. (d) After the weight is dropped, the test piece is checked for "breakage" or "non-breakage." The above operations (a) to (d) were performed on 20 test pieces, and the test pieces were evaluated according to the following criteria: G: 10 or more test pieces did not break. NG: Less than 10 test pieces did not break.

[0056] <Tensile Test> (1) Preparation of Test Pieces for Tensile Tests The resin compositions obtained in the examples and comparative examples were prepared using a reduced pressure hot press ("IMC-183B" manufactured by Imoto Machinery Co., Ltd.) and reduced in pressure to -0.1 MPaG using an oil rotary pump. After preheating for 5 minutes at a predetermined temperature (190 ° C. for Examples 1 to 14 and Comparative Examples 1 to 3, 200 ° C. for Examples 15 to 28 and Comparative Examples 4 to 6, and 150 ° C. for Examples 29 to 42 and Comparative Examples 7 to 9), the resin compositions were pressed at 8 MPa for 3 minutes. Then, the resin compositions were pressed at 8 MPa for 3 minutes using a cooling press equipped with water flow cooling to prepare a 1.0 mm thick press plate. JIS No. 3 dumbbell-shaped test pieces were punched out from the obtained press plate. (2) Measurement of breaking elongation The prepared dumbbell-shaped test pieces were stored at 23°C and a relative humidity of 49% for 24 hours or more, and evaluated using a universal testing machine (Instron Corporation, "INSTRON5900R-5666") at 23°C, a relative humidity of 49%, at a tensile speed of 20 mm / min, to measure the breaking elongation (breaking strain) (%). The measured value was the average of 5 measurements.

[0057] <Bleeding Resistance Test> The dumbbell-shaped test pieces prepared in the above-mentioned method for preparing test pieces for tensile tests were stored at 80°C for 16 hours or more, and the surface condition was evaluated visually and by touch according to the following criteria: VG: No clear bleed-out or stickiness was observed. G: Slight bleed-out or stickiness was observed, but at a level that is acceptable for practical use. NG: Significant bleed-out or stickiness was observed, and the product was not suitable for practical use.

[0058] <Biodegradability (Compost) Test> (1) Preparation of Test Specimens for Biodegradability Test Press plates prepared for impact resistance tests were cut into 10 mm x 10 mm pieces to prepare test specimens. Using these test specimens, biodegradability was evaluated in accordance with JIS K 6953-1:2011, according to the following procedure. (2) Measurement of Total Organic Carbon Amount and Total Amount of Theoretical Carbon Dioxide Generation The total organic carbon amounts of the test specimens and the control material (cellulose microcrystals (manufactured by MERCK)) were measured using an organic trace element analyzer ("Microcoder JM10" manufactured by J Science Lab Co., Ltd.), and the theoretical amount of carbon dioxide generation was calculated based on the results. (3) Biodegradability Evaluation 10 g of the prepared test specimens and the control material and 60 g of compost ("YK-12 Inoculum" manufactured by Yawata Bussan Co., Ltd.) were mixed in a 500 mL compost container, and the container was left to stand in an environment of 58 ± 2°C for incubation. The amount of carbon dioxide generation during the incubation period was measured using the CO ２ / H ２ Measurements were made using an O gas analyzer "LI-850" (manufactured by LI-COR Corporation), and calculations were made using the non-dispersive infrared absorption method. A blank test was also conducted in the same manner, using no test piece. The biodegradability was calculated using the following formula: Biodegradability = {(CO ２ ) Ｔ -(CO ２ ) Ｂ / ThCO ２ ×100 (CO ２ ) Ｔ : Total cumulative amount of carbon dioxide released from the compost container during the incubation period (CO ２ ) Ｂ : Average cumulative amount of carbon dioxide released by the blank test ThCO ２ : Theoretical total amount of carbon dioxide of the test piece in the test container (compost container) A biodegradability of 60% or more after 180 days was rated as pass ("A"), and a biodegradability of less than 60% was rated as fail ("B").

[0059] [Materials] The materials used in the examples and comparative examples are as follows.

[0060] (Polyhydroxyalkanoic acid polymer) Trade name "Poly(3-hydroxybutyric acid) natural origin, average Mn ~ 500,000" (manufactured by Aldrich, PHB, weight average molecular weight: 670,000, content of the first monomer unit represented by formula (M1) is 99.8 mol%). Trade name "Poly(3-hydroxybutyric acid-co-3-hydroxyvaleric acid) natural origin, PHV content 8 mol%" (poly(3-hydroxybutanoic acid-co-3-hydroxyvaleric acid), manufactured by Aldrich, weight-average molecular weight: 650,000, containing a first monomer unit represented by formula (M1) and a second monomer unit represented by formula (M2), with the molar amount M1 of the former and the molar amount M2 of the latter being in a ratio of M1 / M2 = 92 / 8). - Trade name "EM5400A" (P3HB4HB, manufactured by Ecomann, poly(3-hydroxybutanoic acid-co-4-hydroxybutanoic acid), weight-average molecular weight: 1,050,000, containing randomly repeating first monomer units represented by formula (M1) and third monomer units represented by formula (M3), with the molar amount M1 of the former and the molar amount M3 of the latter being in a ratio of M1 / M3 = 86 / 14).

[0061] (Polyester Polymer (A)) [Production Example 1] A flask equipped with an apparatus for distilling off generated liquid and a vacuum pump was charged with 164 g (1.39 mol) of 3-methyl-1,5-pentanediol and 127 g (0.87 mol) of adipic acid (so that the molar ratio of 3-methyl-1,5-pentanediol / adipic acid was 1.6 / 1), and the mixture was heated under a nitrogen atmosphere at normal pressure at 160°C for 3 hours and then at 220°C for 3 hours, while distilling off water, to carry out a reaction. Next, 0.15 g (0.51 mmol; 150 μL) of tetraisopropyl titanate was added, and the mixture was reacted for 3 hours under a reduced pressure of 2,000 Pa, and then further reduced pressure to 80 Pa to carry out the reaction, thereby obtaining a polyester polyol having the target molecular weight. Next, 200.0 g of the obtained polyester polyol and 94.3 g of toluene were added to a 1,000 mL four-neck glass flask, and 196.1 g (1.9 mol) of acetic anhydride was added to the solution. Next, 9.7 g (80 mmol) of 4-dimethylaminopyridine dissolved in 97.7 g of toluene was added, and the mixture was stirred at 40°C for 60 minutes to obtain a reaction solution with acetylated terminals. The resulting reaction solution was extracted with toluene and water and purified by distillation to obtain 210.0 g of polyester polymer (A-1).

[0062] <Ratio (molar ratio) of each constituent component of polyester-based polymer> In the production examples, the ratio of each constituent component of the obtained polyester-based polymer was １ The molar ratio was determined by H-NMR measurement. From the spectrum obtained, the molar ratio was derived from the area ratio of the signal at 4.05-4.18 ppm derived from 3-methyl-1,5-pentanediol, the signal at 4.00-4.05 ppm derived from trimethylolpropane, and the signal at 2.02-2.08 ppm derived from adipic acid and / or sebacic acid. (Measurement conditions) Apparatus: 400YH (manufactured by JEOL Ltd.) Solvent: deuterated chloroform (CDCl3) Measurement temperature: 23°C Number of accumulations: 32

[0063] Production Example 2 A polyester polymer (A-2) was obtained in the same manner as in Production Example 1, except that the amounts of 3-methyl-1,5-pentanediol and adipic acid were changed to 149 g (1.26 mol) of 3-methyl-1,5-pentanediol and 146 g (1.00 mol) of adipic acid (molar ratio: 3-methyl-1,5-pentanediol / adipic acid=1.26 / 1).

[0064] Production Example 3 A polyester polymer (A-3) was obtained in the same manner as in Production Example 1, except that the raw material charges were changed to 106 g (0.90 mol) of 3-methyl-1,5-pentanediol, 59 g (0.45 mol) of trimethylolpropane, and 131 g (0.90 mol) of adipic acid (3-methyl-1,5-pentanediol was replaced with a mixture of 3-methyl-1,5-pentanediol / trimethylolpropane in a molar ratio of 2 / 1).

[0065] Production Example 4 A polyester polymer (A-4) was obtained in the same manner as in Production Example 2, except that the raw material charges were changed to 119 g (1.00 mol) of 3-methyl-1,5-pentanediol, 33.5 g (0.25 mol) of trimethylolpropane, and 147 g (1.00 mol) of adipic acid (3-methyl-1,5-pentanediol was replaced with a mixture of 3-methyl-1,5-pentanediol / trimethylolpropane in a molar ratio of 4 / 1).

[0066] Production Example 5 A polyester polymer (A-5) was obtained in the same manner as in Production Example 1, except that 176 g (0.87 mol) of sebacic acid was used instead of adipic acid.

[0067] Production Example 6 A polyester polymer (A-6) was obtained in the same manner as in Production Example 1, except that the raw material charges were changed to 65.6 g (0.56 mol) of 3-methyl-1,5-pentanediol, 133 g (0.91 mol) of adipic acid, and 92.4 g (0.71 mol) of 2-ethylhexanol (the molar ratio of raw material charges was 3-methyl-1,5-pentanediol / adipic acid / 2-ethylhexanol=0.61 / 1 / 0.78), and the terminal modification step was not performed.

[0068] Production Example 7 A polyester polymer (A-7) was obtained in the same manner as in Production Example 1, except that the amounts of 3-methyl-1,5-pentanediol and adipic acid were changed to 133 g (1.12 mol) of 3-methyl-1,5-pentanediol and 158 g (1.08 mol) of adipic acid (the molar ratio of 3-methyl-1,5-pentanediol to adipic acid was 3-methyl-1,5-pentanediol / adipic acid=1.04 / 1).

[0069] Production Example 8 A polyester polymer (A-9) was obtained in the same manner as in Production Example 1, except that the raw material charges were changed to 65.6 g (0.56 mol) of 3-methyl-1,5-pentanediol, 133 g (0.91 mol) of adipic acid, and 52.6 g (0.71 mol) of propionic acid (the raw material charge molar ratio was 3-methyl-1,5-pentanediol / adipic acid / propionic acid=0.61 / 1 / 0.78), and the terminal modification step was not performed.

[0070] Comparative Production Example 1 A polyester polymer (A-8) was obtained in the same manner as in Production Example 1, except that 125 g (1.39 mol) of 1,4-butanediol was used instead of 3-methyl-1,5-pentanediol.

[0071] (Plasticizer) Plasticizer 1: DAIFATTY-101 (Daihachi Chemical Industry Co., Ltd.)

[0072]

[0073] [Examples 1 to 16] The polyester polymers (A-1) to (A-7) and (A-9) obtained in Production Examples 1 to 8, and a polyhydroxyalkanoic acid polymer (PHBV), were each charged into a twin-screw kneader (manufactured by Technovel Co., Ltd., product name "ULTnano 50") in the formulations shown in Table 2-1, extruded into strands at a cylinder temperature of 170°C, a screw rotation speed of 50 rpm, and a residence time of 1 minute, and the resulting strands were cut into pellets to obtain resin compositions. The resulting resin compositions were evaluated as described above. The results are shown in Table 2-1.

[0074] Comparative Example 1 A resin composition was obtained in the same manner as in Example 1, except that the polyester polymer (A-8) was used instead of the polyester polymer (A-1). The obtained resin composition was subjected to the above-described evaluations. The results are shown in Table 2-1.

[0075] Comparative Example 2 A resin composition was obtained in the same manner as in Example 1, except that plasticizer 1 was used in place of polyester polymer (A-1) in the formulation shown in Table 2-1. The obtained resin composition was evaluated as described above. The results are shown in Table 2-1.

[0076] Comparative Example 3 A resin composition was obtained in the same manner as in Example 1, except that the polyester polymer (A-1) was not used. The obtained resin composition was evaluated as described above. The results are shown in Table 2-1.

[0077] [Examples 17 to 32] Resin compositions were obtained in the same manner as in Example 1, with the formulations shown in Table 2-2, except that a polyhydroxyalkanoic acid polymer (PHB) was used instead of the polyhydroxyalkanoic acid polymer (PHBV) and the cylinder temperature was set to 200°C. The obtained resin compositions were evaluated as described above. The results are shown in Table 2-2.

[0078] [Comparative Example 4] A resin composition was obtained in the same manner as in Example 17, except that the polyester polymer (A-8) was used instead of the polyester polymer (A-1). The obtained resin composition was subjected to the above-described evaluations. The results are shown in Table 2-2.

[0079] Comparative Example 5 A resin composition was obtained in the same manner as in Example 17, except that plasticizer 1 was used in place of polyester polymer (A-1) in the formulation shown in Table 2-2. The obtained resin composition was evaluated as described above. The results are shown in Table 2-2.

[0080] [Comparative Example 6] A resin composition was obtained in the same manner as in Example 17, except that the polyester polymer (A-1) was not used. The obtained resin composition was evaluated as described above. The results are shown in Table 2-2.

[0081] [Examples 33 to 48] Resin compositions were obtained in the same manner as in Example 1, with the formulations shown in Table 2-3, except that a polyhydroxyalkanoic acid polymer (EM5400A: P3HB4HB) was used instead of the polyhydroxyalkanoic acid polymer (PHBV) and the cylinder temperature was set to 150°C. The obtained resin compositions were evaluated as described above. The results are shown in Table 2-3.

[0082] [Comparative Example 7] A resin composition was obtained in the same manner as in Example 33, except that the polyester polymer (A-8) was used instead of the polyester polymer (A-1). The obtained resin composition was subjected to the above-described evaluations. The results are shown in Table 2-3.

[0083] Comparative Example 8 A resin composition was obtained in the same manner as in Example 33, except that plasticizer 1 was used in place of polyester polymer (A-1) in the formulation shown in Table 2-3. The obtained resin composition was evaluated as described above. The results are shown in Table 2-3.

[0084] Comparative Example 9 A resin composition was obtained in the same manner as in Example 33, except that the polyester polymer (A-1) was not used. The obtained resin composition was evaluated as described above. The results are shown in Table 2-3.

[0085]

[0086]

[0087]

[0088] Comparisons of Examples 1 to 16 with Comparative Examples 1 to 3, Examples 17 to 32 with Comparative Examples 4 to 6, and Examples 33 to 48 with Comparative Examples 7 to 9 reveal that the resin compositions obtained in the examples are resin compositions that have good elongation and impact resistance while maintaining biodegradability and bleed-out resistance. It is also clear that the polyester polymers (A-1) to (A-7) and (A-9) obtained in Production Examples 1 to 8 are useful as modifiers for polyhydroxyalkanoic acid polymers.

Claims

1. A resin composition comprising a polyhydroxyalkanoic acid polymer and a polyester polymer, wherein the polyhydroxyalkanoic acid polymer comprises a monomer unit selected from any one of the following (1) to (4): (1) a first monomer unit represented by formula (M1); (2) a first monomer unit represented by formula (M1) and a second monomer unit represented by formula (M2); (3) a first monomer unit represented by formula (M1) and a third monomer unit represented by formula (M3); (4) a first monomer unit represented by formula (M1), a second monomer unit represented by formula (M2), and a third monomer unit represented by formula (M3); wherein the formulas (M1), (M2), and (M3) are represented by the following: (In formula (M2), R １ is a hydrogen atom or an alkyl group having 2 to 4 carbon atoms. ） 　 a resin composition comprising: the polyester polymer comprising a monomer unit having a diol component and a dicarboxylic acid component; the diol of the diol component is a branched aliphatic alkylene diol having a total of 3 to 12 carbon atoms; the dicarboxylic acid of the dicarboxylic acid component is an aliphatic dicarboxylic acid having 4 to 14 carbon atoms, an alicyclic dicarboxylic acid having 5 to 14 carbon atoms, or an aromatic dicarboxylic acid having 6 to 14 carbon atoms; at least a portion of the ends of the polyester polymer are blocked with a residue of a monoalcohol and / or a residue of a monocarboxylic acid; the monoalcohols are each independently an aliphatic monoalcohol having 1 to 10 carbon atoms, an alicyclic monoalcohol having 5 to 12 carbon atoms, or an aromatic monoalcohol having 6 to 12 carbon atoms; and the monocarboxylic acids are each independently an aliphatic monocarboxylic acid having 1 to 10 carbon atoms, or an aromatic monocarboxylic acid having 6 to 12 carbon atoms.

2. The resin composition according to claim 1, which contains 5 to 40 parts by mass of the polyester polymer per 100 parts by mass of the polyhydroxyalkanoic acid polymer.

3. The resin composition according to claim 1 or 2, wherein the ratio of the molar amount of the first monomer unit to the total amount of the first monomer unit, the molar amount of the second monomer unit, and the molar amount of the third monomer unit contained in the polyhydroxyalkanoic acid polymer is 0.20 to 1.00, the ratio of the molar amount of the second monomer unit to the total amount of the first monomer unit, the molar amount of the second monomer unit to the total amount of the third monomer unit to the total amount of the third monomer unit is 0 to 0.

80.

4. The resin composition according to any one of claims 1 to 3, wherein the weight-average molecular weight of the polyhydroxyalkanoic acid polymer is 50,000 to 3,000,000.

5. The resin composition according to any one of claims 1 to 4, wherein the polyester polymer further contains a monomer unit consisting of a trihydric or higher polyhydric alcohol component, and the trihydric or higher polyhydric alcohol component is an aliphatic alkylene polyol having a branched chain and a total of 3 to 12 carbon atoms.

6. A resin composition according to claim 5, wherein the ratio of the molar amount of the diol to the total molar amount of the diol and the trihydric or higher polyhydric alcohol contained in the polyester polymer is 0.20 or more and less than 1.00, and the ratio of the molar amount of the trihydric or higher polyhydric alcohol is more than 0 and 0.80 or less.

7. A resin composition according to any one of claims 1 to 6, wherein the polyester polymer has a hydroxyl value of 150 mgKOH / g or less and an acid value of 50 mgKOH / g or less.

8. The resin composition according to any one of claims 1 to 7, wherein the polyester polymer has a number average molecular weight of 200 to 10,000.

9. The resin composition according to any one of claims 1 to 8, wherein in the polyester polymer, the dicarboxylic acid is an aliphatic dicarboxylic acid having 4 to 10 carbon atoms and a methylene group.

10. The resin composition according to any one of claims 1 to 9, wherein in the polyester polymer, the diol is an aliphatic alkylene diol having a branched chain and a total of 4 to 10 carbon atoms.

11. A resin composition according to any one of claims 5 to 10, wherein in the polyester polymer, the polyhydric alcohol of the trihydric or higher polyhydric alcohol component is a branched alkylene triol having a total of 3 to 6 carbon atoms.

12. A resin composition according to any one of claims 9 to 11, wherein in the polyester polymer, the aliphatic dicarboxylic acid having a methylene group and 4 to 10 carbon atoms is adipic acid or sebacic acid.

13. The resin composition according to any one of claims 10 to 12, wherein in the polyester polymer, the branched aliphatic alkylenediol having a total of 4 to 10 carbon atoms is MPD (3-methyl-1,5-pentanediol) or MOD (2-methyl-1,8-octanediol).

14. The resin composition according to any one of claims 11 to 13, wherein the branched alkylene triol having a total of 3 to 6 carbon atoms is trimethylolpropane.

15. A resin composition according to any one of claims 1 to 14, wherein in the polyester polymer, the monoalcohol is 2-ethylhexanol.

16. A resin composition according to any one of claims 1 to 15, wherein in the polyester polymer, the monocarboxylic acid is acetic acid.

17. A molded article made from the resin composition according to any one of claims 1 to 16.

18. A molded article made from the resin composition according to any one of claims 5 to 16.

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