Resin compositions, molded articles, films

Abstract

To provide resin compositions, molded articles, and films that are highly extensible, have low surface hardness, and have a high biomass content. [Solution] The resin composition according to the present disclosure comprises 20-80% by mass of an aliphatic polyester resin (A) and 80-20% by mass of 2-4 layers of multilayer polymer particles (B), wherein the multilayer polymer particles (B) have at least one rubber component layer (I) inside and at least one thermoplastic resin component layer (II) on the outermost layer, and the thermoplastic resin component layer (II) is composed of a copolymer consisting of 40-100% by mass of methacrylic acid ester monomer units and 60-0% by mass of other monomer units, and the mass ratio (layer (I) / layer (II)) of the total amount of rubber component layer (I) to the total amount of thermoplastic resin component layer (II) is 50 / 50-90 / 10.

Description

Technical Field

[0001] The present disclosure relates to a resin composition, a molded body, and a film.

Background Art

[0002] Conventional general-purpose plastics such as polyethylene and polypropylene have been conventionally produced from petroleum and have been widely used due to their excellent properties. On the other hand, in recent years, from the perspective of preventing global warming by realizing a recycling-based society, the utilization of renewable resources has become an important issue instead of depletable resources such as petroleum, and the use of biomass plastics produced from raw materials including plant-based raw materials has been studied.

[0003] Among biomass plastics, in particular, polylactic acid-based resins, which have relatively high heat resistance and strength, have attracted attention. Lactic acid, which is the raw material for polylactic acid-based resins, is produced from starch extracted from plants such as corn, and thus has the advantage of reducing the total carbon dioxide emissions during production compared to petroleum-derived general-purpose plastics. In recent years, a method has been developed to produce lactic acid, which is the raw material, at low cost by a fermentation method using microorganisms, and its use as a general-purpose plastic has also progressed, and its use in a wide range of applications such as films, sheets, fibers, and miscellaneous goods has been studied. However, since polylactic acid-based resins are hard and brittle, their use may be restricted in applications where flexibility is required.

[0004] Conventionally, techniques for improving the flexibility of polylactic acid-based resins have been proposed. Patent Document 1 discloses a polylactic acid composition composed of a polylactic acid-based resin and an acrylic triblock copolymer. Patent Document 2 discloses a biodegradable plastic film containing a polylactic acid-based resin and a specific acrylic rubber polymer.

Prior Art Documents

Patent Documents

[0005] (end)

Patent Document 1

[0006] The technologies described in Patent Document 1 or 2 could not fully satisfy both high elongation and low surface hardness, and there was a need for a resin composition, molded article, or film containing biomass plastic that possessed all of these properties.

[0007] The object of this disclosure is to provide resin compositions, molded articles, and films that are highly extensible, have low surface hardness, and have a high biomass content. [Means for solving the problem]

[0008] As a result of diligent research to achieve the above objective, the inventors have completed the present invention, which encompasses the following embodiments. [1] A resin composition comprising 20-80% by mass of an aliphatic polyester resin (A) and 80-20% by mass of 2-4 layered multilayer polymer particles (B), The multilayer polymer particle (B) has at least one rubber component layer (I) inside and at least one thermoplastic resin component layer (II) on the outermost layer. The thermoplastic resin component layer (II) is composed of a copolymer consisting of 40-100% by mass of methacrylic acid ester monomer units and 60-0% by mass of other monomer units. A resin composition in which the mass ratio (layer(I) / layer(II)) of the total amount of rubber component layer (I) to the total amount of thermoplastic resin component layer (II) is 50 / 50 to 90 / 10. [2] The resin composition according to [1], characterized in that the rubber component layer (I) of the multilayer polymer particles (B) is composed of a copolymer consisting of 50 to 99.99% by mass of acrylic acid ester monomer units, 49.99 to 0% by mass of other monofunctional monomer units, and 0.01 to 10% by mass of polyfunctional monomer units. [3] The resin composition according to [1], wherein the average particle size of the multilayer polymer particles (B) is 30 to 150 nm. [4] The resin composition according to [1], wherein the weight-average molecular weight of the outermost layer of the multilayer polymer particles (B) is 1,000 to 30,000. [5] The resin composition according to [1], wherein the acetone swelling degree of the acetone-insoluble portion of the multilayer polymer particles (B) is 500 to 1000%. [6] The resin composition according to [1], wherein a 1 mm thick sheet made of the resin composition has a tensile elongation at break of 50 to 400% as measured in accordance with JIS K 6251. [7] The resin composition according to [1], wherein the aliphatic polyester resin (A) is a polylactic acid resin. [8] The resin composition according to [1], wherein the biomass content is 20% or more. [9] A resin composition comprising an aliphatic polyester resin (A) and multilayer polymer particles (B) consisting of 2 to 4 layers, The content of multilayer polymer particles (B) in the resin composition (RB [mass %]), the content of the rubber component layer (I) in the multilayer polymer particles (B) (RI [mass %]), and the degree of acetone swelling of the acetone-insoluble portion of the multilayer polymer particles (B) (VA [%]) are, RB × RI × VA / 10000 ≥ 100 The resin composition described in [1] that satisfies the relationship.

[10] A molded article comprising the resin composition described in any one of items [1] to [9].

[11] A film comprising the resin composition described in any one of items [1] to [9]. [Effects of the Invention]

[0009] According to the present invention, it is possible to obtain resin compositions, molded articles, and films that are highly extensible, have low surface hardness, and have a high biomass content. [Modes for carrying out the invention]

[0010] Hereinafter, an example of an embodiment to which the present disclosure is applied will be described. The present disclosure is not limited to this embodiment, and other embodiments may belong to the scope of the present disclosure as long as they conform to the gist of the present disclosure. In the present disclosure, "~" indicating a numerical range includes the numerical values described before and after it as the lower limit value and the upper limit value, unless otherwise specified.

[0011] (Resin Composition) The resin composition of the present disclosure contains an aliphatic polyester resin (A) and multilayer structure polymer particles (B). In the resin composition of the present disclosure, the content of the aliphatic polyester resin (A) is 20 to 80% by mass, and the content of the multilayer structure polymer particles (B) is 80 to 20% by mass.

[0012] (Aliphatic Polyester Resin (A)) The content of the aliphatic polyester resin (A) in the resin composition of the present disclosure is 20 to 80% by mass. The lower limit value is preferably 25% by mass, more preferably 30% by mass. The upper limit value is preferably 75% by mass, more preferably 70% by mass. When the content of the aliphatic polyester resin (A) in the resin composition of the present disclosure is not less than the above lower limit value, the biomass degree is excellent. When the content of the aliphatic polyester resin (A) is not more than the above upper limit value, the flexibility and mechanical properties are excellent.

[0013] The aliphatic polyester resin (A) is preferably a biomass resin from the viewpoints of the biomass degree of the resin composition and the environmental load during production. Examples of aliphatic polyester resins (A) include polylactic acid (PLA), polycaprolactone (PCL), poly(caprolactone / butylene succinate) (PCLBS), polybutylene succinate (PBS), poly(butylene succinate / adipate) (PBSA), poly(butylene succinate / carbonate) (PEC), poly(ethylene terephthalate / succinate) (PETS), poly(butylene adipate / terephthalate) (PBAT), poly(tetramethylene adipate / terephthalate) (PTMT), polyethylene succinate (PES), polyglycolic acid (PGA), polyethylene furanoate (PEF), polyhydroxyalkanoate (PHA) [e.g., polyhydroxybutyrate (PHB), polyhydroxybutyrate variate (PHBV), etc.], and copolymers containing these. Aliphatic polyester resin (A) may be used alone or in combination of two or more types.

[0014] From the viewpoint of biomass content, heat resistance, hydrolysis resistance, etc., the aliphatic polyester resin (A) is preferably PLA, PBS, and PHA, and more preferably PLA and its copolymers, i.e., polylactic acid resins.

[0015] When a polylactic acid resin is used as the aliphatic polyester resin (A), the polylactic acid resin can be at least one selected from the group consisting of L-lactic acid homopolymers, D-lactic acid homopolymers, copolymers of L-lactic acid and D-lactic acid, DL-lactic acid homopolymers, copolymers of DL-lactic acid and L-lactic acid, copolymers of DL-lactic acid and D-lactic acid, and polymers of lactide, which is a cyclic dimer of lactic acid.

[0016] Furthermore, the polylactic acid resin may be a copolymer of lactic acid and other aliphatic hydroxycarboxylic acids, aliphatic dicarboxylic acids, aliphatic diols, and aromatic dicarboxylic acids other than lactic acid. The copolymer preferably contains 70 mol% or more of structural units derived from lactic acid, more preferably 80 mol% or more, and even more preferably 90 mol% or more. Among these, L-lactic acid homopolymers, D-lactic acid homopolymers, or copolymers of L-lactic acid and D-lactic acid are preferred as polylactic acid resins, with L-lactic acid homopolymers being more preferred. Polylactic acid resins may be used individually or in combination of two or more types.

[0017] When the polylactic acid resin is a copolymer of L-lactic acid and D-lactic acid, from the viewpoint of increasing the crystallinity of the polylactic acid resin and improving heat resistance and mechanical properties, it is preferable that the content of either structural units derived from L-lactic acid or structural units derived from D-lactic acid be 80 to 99.99% by mass, more preferably 90 to 99.9% by mass, and even more preferably 95 to 99.9% by mass. Furthermore, in order to obtain a highly crystalline polylactic acid resin, it is preferable to have a high content of structural units derived from L-lactic acid. Specifically, in the copolymer of L-lactic acid and D-lactic acid, the content of structural units derived from L-lactic acid is preferably 80 to 99.99% by mass, more preferably 90 to 99.9% by mass, and even more preferably 95 to 99.9% by mass. The amount of L-isomer or D-isomer in a polylactic acid resin can be measured, for example, using gas chromatography.

[0018] Commercially available polylactic acid resins may be used. Examples of commercially available products include the "Ingeo series" from NatureWorks, the "Luminy series" from Total Energies Corbion, the "Revode" series from Zhejiang Hisun Biomaterials Co., Ltd, and "SUPLA" from SUPLA Material Technology Co., Ltd.

[0019] The weight-average molecular weight of the polylactic acid resin is preferably 50,000 or more, more preferably 100,000 or more, and even more preferably 150,000 or more, from the viewpoint of tensile properties and heat resistance, and preferably 600,000 or less, more preferably 550,000 or less, and even more preferably 500,000 or less, from the viewpoint of moldability. The weight-average molecular weight of polylactic acid resins can be determined by gel permeation chromatography (GPC) measurement, converted to standard polystyrene equivalents. Alternatively, when using commercially available products, catalog values ​​may be used.

[0020] (Multilayer structure polymer particles (B)) The multilayer polymer particle (B) has at least one rubber component layer (I) (also simply called layer (I)) inside, and at least one thermoplastic resin component layer (II) (also simply called layer (II)) on the outermost layer. This particle has a core-shell structure consisting of an interior containing one or more rubber component layers and an exterior consisting of one or more thermoplastic resin component layers. In the multilayer polymer particle (B), the core is considered a "layer". The number of layers in the multilayer polymer particle (B) is 2 to 4.

[0021] The components constituting the rubber component layer (I) are not particularly limited and include, for example, crosslinked polymers having acrylic acid ester units and crosslinked polymers having conjugated diene monomer units. The thermoplastic resin constituting the thermoplastic resin component layer (II) is a copolymer consisting of 40 to 100% by mass of methacrylic acid ester monomer units and 60 to 0% by mass of other monomer units.

[0022] Examples of layer structures include a two-layer structure of layer(I)-layer(II) from the center; a three-layer structure of layer(I)-layer(I)-layer(II), layer(I)-layer(II)-layer(II), or layer(II)-layer(I)-layer(II); and a four-layer structure such as layer(I)-layer(II)-layer(I)-layer(II). Among these, a two-layer structure of layer(I)-layer(II); or a three-layer structure of layer(I)-layer(I)-layer(II) or layer(II)-layer(I)-layer(II) are preferred from the viewpoint of ease of handling.

[0023] The mass ratio (layer(I) / layer(II)) of the total amount of rubber component layer (I) to the total amount of thermoplastic resin component layer (II) is 50 / 50 to 90 / 10. If the ratio of layer(I) to layer(II) is less than the above range, the flexibility of the resin composition may be insufficient. If the ratio of layer(I) exceeds the above range, it may become difficult to form the particle structure, and the melt fluidity of the multilayer polymer particles (B) may decrease, making it difficult to melt-mix with other components and mold the resin composition. The mass ratio (layer(I) / layer(II)) is preferably 60 / 40 to 90 / 10, more preferably 65 / 35 to 80 / 20.

[0024] Layer (I) is preferably composed of a crosslinked copolymer consisting of 50 to 99.99% by mass of acrylic acid ester monomer units, 49.99 to 0% by mass of other monofunctional monomer units, and 0.15 to 10% by mass of polyfunctional monomer units. This copolymer preferably contains other monomer units. The content of acrylic acid ester monomer units is preferably 55 to 99.9% by mass, the content of other monofunctional monomer units is preferably 44.9 to 0% by mass, and the content of polyfunctional monomer units is preferably 0.16 to 2% by mass.

[0025] If the amount of acrylic acid ester monomer units is below the lower limit, the rubber elasticity of the multilayer polymer particles (B) may decrease, potentially reducing the weather resistance of the resin composition. If the amount exceeds the upper limit, the layer structure of the multilayer polymer particles (B) may not be formed in a complete form, and the melt-fluidity of the multilayer polymer particles (B) may decrease, making melt-mixing with other components and molding of the resin composition difficult. If the amount of polyfunctional monomer units exceeds the upper limit, the rubber elasticity of the multilayer polymer particles (B) may decrease, potentially resulting in insufficient flexibility of the resin composition. If the amount of acrylic acid ester monomer units is below the lower limit, the layer (I) may not be formed as a particle structure.

[0026] The following describes an example of the raw material monomer (i) of layer (I). Examples of acrylic acid esters include methyl acrylate (MA), ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate (BA), isobutyl acrylate, s-butyl acrylate, t-butyl acrylate, pentyl acrylate, hexyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, dodecyl acrylate, and octadecyl acrylate, which are acrylic acid and saturated aliphatic alcohols (preferably C1-C1). 18 Examples include esters of acrylic acid with saturated aliphatic alcohols; esters of acrylic acid with C5 or C6 alicyclic alcohols such as cyclohexyl acrylate; esters of acrylic acid with phenols such as phenyl acrylate; and esters of acrylic acid with aromatic alcohols such as benzyl acrylate. One or more of these can be used.

[0027] A polyfunctional monomer is a monomer having two or more carbon-carbon double bonds in its molecule. Examples of polyfunctional monomers include esters of unsaturated monocarboxylic acids such as (meth)acrylic acid and cinnamic acid with unsaturated alcohols such as (meth)allyl alcohol; diesters of the aforementioned unsaturated monocarboxylic acids with glycols such as ethylene glycol, butanediol, and hexanediol; and esters of dicarboxylic acids such as phthalic acid, terephthalic acid, isophthalic acid, and maleic acid with the aforementioned unsaturated alcohols. Specifically, examples include allyl acrylate, methallyl acrylate, allyl methacrylate (ALMA), methallyl methacrylate, (meth)allyl cinnamate, diallyl maleate, diallyl phthalate, diallyl terephthalate, diallyl isophthalate, divinylbenzene, ethylene glycol di(meth)acrylate, butanediol di(meth)acrylate, and hexanediol di(meth)acrylate. One or more of these can be used. Among these, allyl methacrylate (ALMA) is preferred.

[0028] Other monofunctional monomers include methyl methacrylate (MMA), ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, pentyl methacrylate, hexyl methacrylate, octyl methacrylate, 2-ethylhexyl methacrylate, dodecyl methacrylate, myristyl methacrylate, palmityl methacrylate, stearyl methacrylate, and behenyl methacrylate, which are methacrylic acid and saturated aliphatic alcohols (preferably C1-C1). 22 Examples include esters of methacrylic acid with saturated aliphatic alcohols; esters of methacrylic acid with C5 or C6 alicyclic alcohols such as cyclohexyl methacrylate; esters of methacrylic acid with phenols such as phenyl methacrylate, and esters of methacrylic acid with aromatic alcohols such as benzyl methacrylate; aromatic vinyl monomers such as styrene (St), α-methylstyrene, 1-vinylnaphthalene, 3-methylstyrene, 4-propylstyrene, 4-cyclohexylstyrene, 4-dodecylstyrene, 2-ethyl-4-benzylstyrene, 4-(phenylbutyl)styrene, and halogenated styrenes; and vinyl cyanide monomers such as (meth)acrylonitrile. One or more of these can be used.

[0029] Furthermore, layer (I) may be composed of a crosslinked polymer containing conjugated diene monomer units. Examples of conjugated diene monomer units include 1,3-butadiene, isoprene, and β-farnesene. One or more of these can be used. Among these, β-farnesene is preferred from the viewpoint of biomass content. Multilayer polymer particles having a crosslinked polymer containing β-farnesene units as layer (I) can be prepared, for example, according to the description in WO2017 / 038724.

[0030] Layer (II) consists of a crosslinked or uncrosslinked copolymer comprising 40 to 100% by mass of methacrylic acid ester monomer units and 60 to 0% by mass of other monomer units. This copolymer preferably contains other monomer units. The content of methacrylic acid ester monomer units is preferably 60 to 99% by mass, more preferably 80 to 99% by mass, and the content of other monomer units is preferably 40 to 1% by mass, more preferably 20 to 1% by mass. If the content of methacrylic acid ester monomer units is below the above lower limit, the compatibility between the multilayer polymer particles (B) and other components will decrease, and the dispersibility of the multilayer polymer particles (B) during melt kneading and molding may be insufficient.

[0031] The following describes an example of the raw material monomer (ii) of layer (II). Examples of methacrylic acid esters include methyl methacrylate (MMA), ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, pentyl methacrylate, hexyl methacrylate, octyl methacrylate, 2-ethylhexyl methacrylate, cyclohexyl methacrylate, dodecyl methacrylate, myristyl methacrylate, palmityl methacrylate, stearyl methacrylate, behenyl methacrylate, octadecyl methacrylate, phenyl methacrylate, and benzyl methacrylate. One or more of these can be used. Among these, methyl methacrylate (MMA) is preferred.

[0032] Other monomers include methyl acrylate (MA), ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate (BA), isobutyl acrylate, s-butyl acrylate, t-butyl acrylate, pentyl acrylate, hexyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, dodecyl acrylate, and octadecyl acrylate, which are acrylic acids and saturated aliphatic alcohols (preferably C1-C1). 18Examples include esters of acrylic acid with saturated aliphatic alcohols; esters of acrylic acid with C5 or C6 alicyclic alcohols such as cyclohexyl acrylate; aromatic vinyl monomers such as styrene (St), α-methylstyrene, 1-vinylnaphthalene, 3-methylstyrene, 4-propylstyrene, 4-cyclohexylstyrene, 4-dodecylstyrene, 2-ethyl-4-benzylstyrene, 4-(phenylbutyl)styrene, and halogenated styrenes; vinyl cyanide monomers such as (meth)acrylonitrile; maleimide monomers such as maleimide, N-methylmaleimide, N-ethylmaleimide, N-propylmaleimide, N-isopropylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, N-(p-bromophenyl)maleimide, and N-(chlorophenyl)maleimide; and polyfunctional monomers as exemplified in layer (I). One or more of these can be used. Among these, alkyl acrylates such as methyl acrylate (MA), ethyl acrylate, and n-butyl acrylate (BA) are preferred.

[0033] In the multilayer polymer particles (B), the weight-average molecular weight (Mw) of the non-crosslinked copolymer in the outermost layer (II), as measured by the following method, is preferably 1,000 to 30,000. The upper limit is more preferably 25,000, even more preferably 20,000, and particularly preferably 15,000. The lower limit is more preferably 3,000, even more preferably 5,000, and particularly preferably 8,000. If the Mw of the copolymer exceeds the upper limit, the flexibility and melt flowability of the resin composition may be insufficient. If the Mw of the copolymer is equal to or greater than the lower limit, the process passability of the multilayer polymer particles (B) in the production process will be good.

[0034] In this specification, unless otherwise specified, the weight-average molecular weight (Mw) is measured by GPC (gel permeation chromatography), and the value obtained by converting the chromatogram measured by GPC to the molecular weight of standard polystyrene. The weight-average molecular weight (Mw) of the copolymer constituting the outermost layer of the multilayer polymer particle (B) can be determined by subjecting the acetone-soluble portion of the multilayer polymer particle (B), obtained by solvent extraction of the multilayer polymer particle (B) with acetone, to GPC measurement.

[0035] The average particle size of the multilayer polymer particles (B) is preferably 30 to 150 nm, and more preferably 80 to 120 nm. If the average particle size exceeds the above upper limit, the flexibility and melt flowability of the resin composition may be insufficient. If the average particle size is below the above lower limit, the multilayer polymer particles (B) can be easily manufactured.

[0036] In this specification, unless otherwise specified, "average particle diameter" refers to the volume-average particle diameter (median diameter). The average particle diameter of multilayer polymer particles (B) in latex can be measured by light scattering using a laser diffraction / scattering particle size distribution analyzer. The average particle diameter of multilayer polymer particles (B) in molded articles such as sheets can be measured by transmission electron microscopy or the like.

[0037] As for the multilayer polymer particles (B), from the viewpoint of physical properties and ease of manufacture, multilayer polymer particles (BX) having a three-layer structure consisting of a first rubber component layer (I) (rubber component layer (Ia), a second rubber component layer (I) (rubber component layer (Ib)), and a thermoplastic resin component layer (II) from the center are preferred. From the viewpoint of achieving both flexibility and other mechanical properties (tensile properties, etc.) of the resin composition, the mass ratio ((Ia) / (Ib)) of the rubber component layer (Ia) to the rubber component layer (Ib) is preferably 5 / 95 to 95 / 5, and more preferably 20 / 80 to 80 / 20.

[0038] From the viewpoint of achieving both flexibility and other mechanical properties (tensile properties, etc.) of the resin composition, it is preferable that both rubber component layer (Ia) and rubber component layer (Ib) are mainly composed of a crosslinked polymer containing acrylic acid ester monomer units. In this case, it is preferable that the content of acrylic acid ester monomer units in rubber component layer (Ia) (CAE(Ia) (mass%)) is higher than the content of acrylic acid ester monomer units in rubber component layer (Ib) (CAE(Ib) (mass%)) (CAE(Ia) > CAE(Ib)). Furthermore, it is preferable that the amount obtained by subtracting the content of acrylic acid ester monomer units in the rubber component layer (Ib) (CAE(Ib) (mass%)) from the content of acrylic acid ester monomer units in the rubber component layer (Ia) (CAE(Ia) (mass%)) is 3% by mass or more (3 ≤ [CAE(Ia) - CAE(Ib)]), and more preferably 4 to 30% by mass (4 ≤ [CAE(Ia) - CAE(Ib)] ≤ 30).

[0039] A method for producing multilayer polymer particles (B) comprises a polymerization reaction step (S1) for forming a rubber component layer (I) and a polymerization reaction step (S2) for forming a thermoplastic resin component layer (II). In polymerization reaction step (S1), one or more raw material monomers (i) corresponding to the copolymer composition of the rubber component layer (I) are copolymerized by a known method. Similarly, in polymerization reaction step (S2), one or more raw material monomers (ii) corresponding to the copolymer composition of the thermoplastic resin component layer (II) are copolymerized by a known method.

[0040] In the polymerization reaction step (S2), a molecular weight modifier can be used in a proportion of 0.4 to 10% by mass, more preferably 0.4 to 5% by mass, and particularly preferably 0.6 to 2% by mass, relative to the total amount of raw material monomers (ii). If the amount of molecular weight modifier used is above the lower limit, the Mw of the thermoplastic resin component constituting the outermost layer will stably remain below 30,000, and both flexibility and moldability of the resin composition can be stably achieved. However, even if the amount of molecular weight modifier used exceeds the upper limit, no further improvement in flexibility can be obtained, and only a large amount of unnecessary molecular weight modifier will remain.

[0041] Examples of molecular weight modifiers include mercaptans such as n-octyl mercaptan (n-OM), t-octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, and mercaptoethanol; terpene mixtures consisting of terpinolene, dipentene, t-terpinene, and small amounts of other cyclic terpenes; and halogenated hydrocarbons such as chloroform and carbon tetrachloride. One or more of these can be used in appropriate combinations. Among these, alkyl mercaptans such as n-octyl mercaptan (n-OM) are preferred from the viewpoint of ease of handling.

[0042] The polymerization method for the multilayer polymer particles (B) is not particularly limited and includes emulsion polymerization, suspension emulsion polymerization, solution polymerization, and combinations thereof. Below, as an example, we will describe suitable polymerization conditions for multilayer polymer particles (B) produced by emulsion polymerization.

[0043] The polymerization temperature can be between 0 and 100°C. Examples of emulsifiers include alkali metal salts of fatty acids such as sodium oleate, sodium laurate, and sodium stearate; sulfate esters of fatty alcohols such as sodium lauryl sulfate; rosinates such as potassium rosinate; and alkylaryl sulfonic acids such as dodecylbenzenesulfonic acid. One or more of these can be used in appropriate combinations. Radical polymerization initiators can be used as polymerization initiators. Peroxides such as persulfates, azobisisobutyronitrile, and benzoyl peroxide can be used individually as radical polymerization initiators. Redox initiators can also be used, which are combinations of organic hydroperoxides such as cumene hydroperoxide, diisopropylbenzene hydroperoxide, and paramenthane hydroperoxide with reducing agents such as transition metal salts. The average particle size of the multilayer polymer particles (B) can be controlled within a desirable range by adjusting polymerization conditions such as the amount of emulsifier added. The multilayer polymer particles (B) after polymerization can be separated and obtained from the reaction system by known methods such as acid precipitation, salting out, spray drying, and freeze-coagulation.

[0044] The gel content of the multilayer polymer particles (B) is preferably 50-90% by mass. The lower limit is preferably 55%, more preferably 60%. The upper limit is preferably 85%, more preferably 80%. When the gel content of the multilayer polymer particles (B) is within the above range, the flexibility and mechanical properties of the resin composition are good. The gel content of the multilayer polymer particles (B) can be determined from the mass wd of the multilayer polymer particles (B) after solvent extraction using acetone and drying of the acetone-insoluble components, and the mass w0 of the multilayer polymer particles (B) before immersion in acetone, using the following formula. Gel content (%) = (wd / w0) × 100

[0045] The acetone swelling degree of the multilayer polymer particles (B) is preferably 400 to 1000%. The lower limit is preferably 450%, more preferably 500%. The upper limit is preferably 900%, more preferably 800%. When the acetone swelling degree of the multilayer polymer particles (B) is within the above range, the flexibility and mechanical properties of the resin composition are good. The degree of acetone swelling of multilayer polymer particles (B) can be determined from the mass wa of the acetone-insoluble portion of the multilayer polymer particles (B) obtained by solvent extraction of the multilayer polymer particles (B) using acetone, and the mass wd of the acetone-insoluble portion after it has dried, using the following formula. Acetone swelling degree (%) = (wa / wd) × 100 The method for adjusting the degree of acetone swelling of the multilayer polymer particles (B) is not particularly limited, but can be adjusted, for example, by increasing or decreasing the amount of polyfunctional monomer used when forming the rubber component layer (I) of the multilayer polymer particles (B).

[0046] In another embodiment of the resin composition of the present disclosure, the content of multilayer polymer particles (B) (RB [mass %]), the content of rubber component layer (I) in the multilayer polymer particles (B) (RI [mass %]), and the degree of acetone swelling of the acetone-insoluble portion of the multilayer polymer particles (B) (VA [%]) are: RB × RI × VA / 10000 ≥ 100 It satisfies the relationship. The RB×RI×VA / 10000 ratio is 100 or more, preferably 110 or more, and more preferably 120 or more. Setting the RB×RI×VA / 10000 ratio to 100 or more improves the tensile elongation at break of the resin composition. There is no particular upper limit, but it is usually 5000 or less.

[0047] In addition to the aliphatic polyester resin (A) and multilayer polymer particles (B), the resin composition of this disclosure may also contain methacrylic resin (M), other resins, plasticizers, and other additives.

[0048] (Methacrylic resin (M)) The resin composition of this disclosure may optionally contain one or more methacrylic resins (M). The number-average molecular weight (Mn) of the methacrylic resin (M), as measured by GPC, is not particularly limited, but is preferably 10,000 to 100,000, more preferably 15,000 to 50,000. When the resin composition of this disclosure preferably contains a methacrylic resin (M) with Mn within the above range, the resin composition will have better moldability. The content of the methacrylic resin (M) in the resin composition of this disclosure is not particularly limited, but from the viewpoint of improving the flexibility and moldability of the resin composition, it is preferably 1 to 20 parts by mass, more preferably 1 to 10 parts by mass, per 100 parts by mass of the total of the aliphatic polyester resin (A) and the multilayer polymer particles (B).

[0049] The methacrylic resin (M) is a homopolymer or copolymer of one or more (meth)acrylic acid esters containing methyl methacrylate (MMA) units. The content of MMA units in the methacrylic resin (M) is preferably 40 to 100% by mass, more preferably 70 to 100% by mass, and particularly preferably 90 to 100% by mass.

[0050] Other methacrylate esters besides MMA include alkyl methacrylates such as ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, pentyl methacrylate, hexyl methacrylate, heptyl methacrylate, 2-ethylhexyl methacrylate, nonyl methacrylate, decyl methacrylate, and dodecyl methacrylate; 1-methylcyclopentyl methacrylate, cyclohexyl methacrylate, cycloheptyl methacrylate, cyclooctyl methacrylate, and tricyclo[5.2.1.0 2,6 Examples include cycloalkyl methacrylates such as deca-8-yl methacrylate; aryl methacrylates such as phenyl methacrylate; and aralkyl methacrylates such as benzyl methacrylate. Among these, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, and t-butyl methacrylate are preferred from the viewpoint of availability.

[0051] Examples of acrylic acid esters include methyl acrylate (MA), ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate (BA), isobutyl acrylate, t-butyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, nonyl acrylate, decyl acrylate, dodecyl acrylate, stearyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, cyclohexyl acrylate, 2-methoxyethyl acrylate, 3-methoxybutyl acrylate, trifluoromethyl acrylate, trifluoroethyl acrylate, pentafluoroethyl acrylate, glycidyl acrylate, allyl acrylate, phenyl acrylate, toluyl acrylate, benzyl acrylate, isobornyl acrylate, and 3-dimethylaminoethyl acrylate. In particular, from the viewpoint of availability, acrylic acid esters such as methyl acrylate (MA), ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate (BA), isobutyl acrylate, and t-butyl acrylate are preferred, methyl acrylate (MA) and ethyl acrylate are more preferred, and methyl acrylate (MA) is particularly preferred.

[0052] (Other resins) There are no particular restrictions on resins other than aliphatic polyester resins (A) and methacrylic resins (M), but resins produced from biomass raw materials are preferred. For example, cellulose resins such as cellulose acetate and general-purpose plastics derived from bionaphtha are suitable examples. These may be used individually or in combination of two or more.

[0053] (Plasticizer) Plasticizers may be included in the resin composition for purposes such as adjusting the viscosity to a level suitable for molding or obtaining molded articles with desired hardness. There are no particular restrictions on the plasticizer, but plasticizers made from biomass raw materials are preferred. For example, plant esters such as rapeseed oil and castor oil, and sugars such as sorbitol are preferred examples. These may be used individually or in combination of two or more.

[0054] (Additives) The resin composition of this disclosure may contain additives in addition to the aliphatic polyester resin (A) and multilayer polymer particles (B). Examples of additives include inorganic fillers, softeners, heat aging inhibitors, antioxidants, hydrolysis inhibitors, light stabilizers, antistatic agents, mold release agents, flame retardants, foaming agents, pigments, dyes, whitening agents, UV absorbers, and lubricants. These may be used individually or in combination of two or more. When using the above-mentioned additives, the amount of the additive in the resin composition can be appropriately determined according to the desired physical properties of the resin composition.

[0055] (Method for manufacturing resin compositions) The resin composition of this disclosure can be produced by mixing an aliphatic polyester resin (A), multilayer polymer particles (B), and one or more optional components as needed, by known methods such as melt kneading. In the melt kneading method, a melt kneader such as a single-screw or twin-screw or more-screw kneader, an open roll, a Banbury mixer, and a kneader can be used, and melt kneading can be performed in an inert gas atmosphere such as nitrogen gas, argon gas, and helium gas as needed. The melt kneading temperature can be appropriately adjusted according to the glass transition temperature (Tg), melting point, decomposition temperature, etc. of the resin material used, and is preferably 110 to 230°C, more preferably 140 to 220°C, and most preferably 160 to 210°C. The melt kneaded product can be processed into forms suitable as molding materials, such as pellets and powders, by known methods.

[0056] (Molded body) The resin composition of this disclosure exhibits excellent melt moldability and can be molded using general molding methods and apparatus for thermoplastic resins. Examples of molding methods include extrusion molding, injection molding, compression molding (also known as press molding), blow molding, calendering, and vacuum molding. The resin composition of this disclosure is particularly suitable for use in extrusion molding.

[0057] Examples of molded articles include single-layer or laminated planar objects such as films, sheets, and plates; pipes; fibrous objects; and any three-dimensional structures. The molded article may also be a laminate or composite comprising layers or members made of the resin composition of this disclosure and layers or members made of other resins or various non-resin materials. Surface treatments such as printing, painting, plating, vapor deposition, and sputtering; and shaping processes such as bending, folding, and cutting (also known as secondary molding) may be performed on the molded article obtained by known methods, as necessary.

[0058] Generally, thin film molded articles are referred to as "film," "sheet," or "plate," depending on their thickness, but there are no clear definitions of these terms, and no clear distinction between them. In this specification, the term "film" may include sheets.

[0059] (film) The thickness of the film containing the resin composition of this disclosure is not particularly limited, but from the viewpoint of shape conformability and mechanical properties, it is preferably 2 to 500 μm, more preferably 5 to 300 μm, and even more preferably 10 to 200 μm.

[0060] The Shore D hardness of a 6 mm thick sheet made of the resin composition of this disclosure, as measured in accordance with JIS K 6253, is preferably 10 to 80, more preferably 20 to 75. In this specification, unless otherwise specified, "Shore D hardness" is the value measured using a durometer with a Type A indenter, in accordance with JIS K 6253.

[0061] A dumbbell-shaped test specimen (Dumbbell-shaped No. 3 as specified in JIS K 6251) can be punched out from a 1 mm thick sheet made of the resin composition of this disclosure, and tensile properties such as tensile elongation at break, tensile strength at break, and tensile modulus can be measured in accordance with JIS K 6251. For specific measurement methods, please refer to the [Examples] section below. The tensile elongation at break is preferably 50 to 400%, more preferably 75 to 300%. The tensile strength at break is preferably 5 to 50 MPa, more preferably 10 to 40 MPa. The tensile modulus is preferably 30 to 400 MPa, more preferably 100 to 300 MPa.

[0062] The resin composition of this disclosure preferably has a biomass content of 20-80%, and more preferably 30-70% by mass. The biomass content is the mass percentage of biomass material in the resin composition. For resin compositions with clearly defined raw materials and their origins, it can be calculated using the mass ratio of petroleum-derived components to biologically derived components. On the other hand, for resin compositions with unknown raw materials or their origins, the biomass content can be determined by radiocarbon dating using an accelerator mass spectrometer (AMS) or similar device, based on ASTM D6866. 14 By determining the concentration of C), radioactive carbon ( 14 C) Based on the principles of dating, the content of petroleum-derived carbon and biogenic carbon can be determined regardless of the form of the sample (AMS method).

[0063] The resin compositions and molded articles using the same can be used for a variety of applications. Suitable applications include films, sheets, plates, pipes, and containers; interior and exterior material parts for vehicles, etc.; building material parts such as wall materials and window frames; home appliance parts such as housings and cable sheathing materials; food packaging materials such as bottles and trays; and daily necessities such as tableware, toys, and stationery. [Examples]

[0064] The present disclosure will now be described in more detail by illustrating the examples. However, the present disclosure is not limited by the examples. The physical properties were measured using the following method.

[0065] (Volume-average particle size) Using latex from multilayer polymer particles (B) as a sample, the volume-average particle diameter (median diameter) of the multilayer polymer particles (B) was measured by light scattering using the LA-950V2 laser diffraction / scattering particle size distribution analyzer manufactured by Horiba, Ltd.

[0066] (Weight average molecular weight) Two g of multilayer polymer particles (B) were placed in 50 mL of acetone and stirred and mixed at 23°C for 24 hours. The entire resulting liquid was centrifuged using a Hitachi CR20GIII centrifuge (rotor: R20A2) at a rotation speed of 20,000 rpm, a temperature of 0°C, and for 90 minutes, and the supernatant was collected. After evaporating the acetone from the supernatant, it was dried under vacuum at 50°C for 8 hours to obtain the residue (acetone-soluble portion). The weight-average molecular weight (Mw) of the obtained residue (polymer constituting the outermost layer of the multilayer polymer particles (B)) was determined by GPC (gel permeation chromatography). A Tosoh HLC-8320 GPC instrument was used as the measurement device. A series-connected configuration of Tosoh TSKguardcolumnSuperHZ-H, TSKgelHZM-M, and TSKgelSuperHZ4000 columns was used as the separation column. A differential refractive index detector (RI detector) was used as the detector. A sample solution was prepared by dissolving 4 mg of the target resin in 5 mL of tetrahydrofuran. The column oven temperature was set to 40°C. Tetrahydrofuran was used as the eluent, and the eluent flow rate was set to 0.35 mL / min. 20 μL of the sample solution was injected into the instrument, and the chromatogram was measured. Ten standard polymethyl methacrylate (PMMA) samples with molecular weights ranging from 400 to 5,000,000 were subjected to GPC measurements, and a calibration curve showing the relationship between retention time and molecular weight was created. Based on this calibration curve, the weight-average molecular weight (Mw) of the target resin was determined.

[0067] (Gel content, degree of acetone swelling) In the measurement of the weight-average molecular weight described above, the precipitated residue (acetone-insoluble matter) after removing the supernatant liquid following centrifugation was collected and its mass was accurately weighed to determine the mass (wa) of the acetone-insoluble matter in its acetone-swollen state. After evaporating the acetone from the collected acetone-insoluble matter, it was dried under vacuum at 50°C for 8 hours, and the mass of the residue was accurately weighed to determine the mass (wd) of the acetone-insoluble matter in its dry state. The gel content and degree of acetone swelling of the acetone-insoluble matter of the multilayer polymer particles (B) were calculated based on the following formula. Note that w0 is the mass of the multilayer polymer particles (B) before immersion in acetone. Gel content (%) = (wd / w0) × 100 Acetone swelling degree (%) = (wa / wd) × 100

[0068] (Shore D hardness) The resin composition was placed in a mold and press-molded at 200°C to obtain a 6 mm thick sheet (press-molded sheet). The Shore D hardness of the obtained sheet was measured using an Asker rubber hardness tester type D (manufactured by Polymer Instruments Co., Ltd.) in accordance with JIS K6253.

[0069] (Tensile properties) A resin composition (C) or (CC) was press-molded at 200°C to obtain a 1 mm thick sheet. Dumbbell-shaped test specimens (Dumbbell-shaped type 3 as specified in JIS K6251) were punched out from the obtained sheet, and the tensile properties were measured in accordance with JIS K6251 using an Autograph (Shimadzu Corporation "AG-1S"). Under conditions of 23°C and 50% relative humidity, the test specimens were uniaxially stretched at a tensile speed of 500 mm / min. The elongation at fracture was determined as the tensile fracture elongation, and the strength at fracture was determined as the tensile fracture strength. The slope of the stress-strain curve within the strain range of 0.05 to 0.25% was determined as the tensile modulus.

[0070] (Biomass content) The biomass content of resin composition (C) or (CC) was determined based on the following formula. Biomass percentage (%) = (Aliphatic polyester resin (A) mass / Total composition mass) × 100 Furthermore, when multilayer polymer particles (B-2) containing monomer units derived from biomass were incorporated, the biomass content of the resin composition (C) was determined based on the following formula. Biomass percentage (%) = [(Aliphatic polyester resin (A) mass + Multilayer polymer particle (B) mass × Biomass-derived monomer unit ratio in multilayer polymer particle (B)) / Total composition mass] × 100

[0071] <Examples of various materials> The aliphatic polyester resin (A) related to this disclosure was made using the materials shown below. ·Aliphatic polyester resin (A-1): Polylactic acid resin “Ingeo2003D” manufactured by NatureWorks LLC (Mw=236,000, D weight / L weight=4.3 / 95.7 (mass ratio)) • Aliphatic polyester resin (A-2): Polylactic acid resin "Ingeo3001D" manufactured by NatureWorks LLC (Mw=162,000, D-size / L-size = 1.5 / 98.5 (mass ratio))

[0072] (Manufacturing Example 1: Manufacturing of multilayer polymer particles (B-1)) Under a nitrogen atmosphere, 150 parts by mass of distilled water, 1.3 parts by mass of emulsifier (Kao Corporation's "Neopelex G-15"), and 1.0 part by mass of dispersant (Kao Corporation's "Poise 520") were added to a polymerizer equipped with a stirring blade, a condenser, and a dropping funnel, and heated to 80°C to dissolve uniformly. Then, at the same temperature, 0.05 parts by mass of a 3% aqueous solution of potassium peroxodisulfate was added, and a mixture consisting of 41.25 parts by mass of n-butyl acrylate (BA), 8.75 parts by mass of styrene (St), 0.20 parts by mass of allyl methacrylate (ALMA), and 0.25 parts by mass of surfactant (ADEKA Corporation's "Adekacol CS-141E") was added dropwise from the dropping funnel over 60 minutes to form the first layer (rubber component layer (Ia)). After the dropping was complete, the reaction was continued at 80°C for another hour, and gas chromatography confirmed that more than 99% of each monomer had been consumed.

[0073] Next, 0.025 parts by mass of a 3% aqueous solution of potassium peroxodisulfate was added to the obtained copolymer latex. Then, a mixture consisting of 1.25 parts by mass of methyl methacrylate (MMA), 19.75 parts by mass of n-butyl acrylate (BA), 4.0 parts by mass of styrene (St), 0.25 parts by mass of allyl methacrylate (ALMA), and 0.13 parts by mass of surfactant ("Adekacol CS-141E") was added dropwise from a dropping funnel over 40 minutes to form the second layer (rubber component layer (Ib)). After the dropwise addition was complete, the reaction was continued at 80°C for another hour, and gas chromatography confirmed that more than 99% of each monomer had been consumed.

[0074] Next, 0.025 parts by mass of a 3% aqueous solution of potassium peroxodisulfate was added to the obtained copolymer latex. Then, a mixture consisting of 23.75 parts by mass of methyl methacrylate (MMA), 1.25 parts by mass of methyl acrylate (MA), 0.25 parts by mass of n-octyl mercaptan (n-OM), and 0.13 parts by mass of surfactant ("Adekacol CS-141E") was added dropwise from a dropping funnel over 40 minutes to form the third layer (thermoplastic resin component layer (IIb)). After the dropwise addition was complete, the reaction was continued at 80°C for another 60 minutes, and polymerization was terminated when it was confirmed by gas chromatography that more than 99.9% of each monomer had been consumed. The average particle size of the particles in the obtained latex, as determined by light scattering, was 100 nm.

[0075] The obtained latex was cooled at -30°C for 24 hours to induce freeze-aggregation, and the aggregate was then thawed and removed. It was dried under reduced pressure at 50°C for 2 days to obtain powdery, three-layered multilayer polymer particles (B-1). The gel content was 79%, the acetone swelling degree of the acetone-insoluble portion was 740%, and the weight-average molecular weight (Mw) of the copolymer constituting the outermost layer was 20,000. The particle structure and physical properties of the obtained multilayer polymer particles are shown in Table 1.

[0076] (Manufacturing Example 2: Manufacturing of multilayer polymer particles (B-2)) Except for the formulation shown in Table 1, the latex of multilayer polymer particles (B-2) was obtained in accordance with the description in Publication No. WO2017 / 038724. The average particle size of the particles in the obtained latex, determined by light scattering, was 100 nm. In Table 1, "Far" represents β-farnesene.

[0077] The obtained latex was cooled at -30°C for 24 hours to induce freeze-aggregation, and the aggregate was then thawed and removed. It was dried under reduced pressure at 50°C for 2 days to obtain powdery, three-layered multilayer polymer particles (B-2). The gel content was 76%, the acetone swelling degree of the acetone-insoluble portion was 600%, and the weight-average molecular weight (Mw) of the copolymer constituting the outermost layer was 20,000. The particle structure and physical properties of the obtained multilayer polymer particles are shown in Table 1.

[0078] (Manufacturing Example 3: Manufacturing of multilayer polymer particles (B-3)) Under a nitrogen atmosphere, 150 parts by mass of distilled water, 1.3 parts by mass of emulsifier (Kao Corporation's "Neopelex G-15"), and 0.05 parts by mass of sodium carbonate were added to a polymerization reactor equipped with a stirring blade, condenser, and dropping funnel, and heated to 80°C to dissolve uniformly. Next, at the same temperature, 0.01 parts by mass of a 3% aqueous solution of potassium peroxodisulfate was added, and then a mixture consisting of 2.52 parts by mass of n-butyl acrylate (BA), 2.52 parts by mass of methyl methacrylate (MMA), and 0.01 parts by mass of allyl methacrylate (ALMA) was added dropwise from the dropping funnel over 10 minutes to form the first layer (thermoplastic resin component layer (IIa)). After the dropwise addition was complete, the reaction was continued at 80°C for a further 25 minutes, and it was confirmed by gas chromatography that more than 99% of each monomer had been consumed.

[0079] Next, 0.09 parts by mass of a 3% aqueous solution of potassium peroxodisulfate was added to the obtained copolymer latex, and then a mixture consisting of 1.52 parts by mass of methyl methacrylate (MMA), 28.5 parts by mass of n-butyl acrylate (BA), and 0.90 parts by mass of allyl methacrylate (ALMA) was added dropwise from a dropping funnel over 50 minutes to form the second layer (rubber component layer (Ib)). After the dropwise addition was complete, the reaction was continued at 80°C for another 30 minutes, and it was confirmed by gas chromatography that more than 99% of each monomer had been consumed.

[0080] Next, a mixture consisting of 56.82 parts by mass of methyl methacrylate (MMA), 8.12 parts by mass of n-butyl acrylate (BA), and 0.19 parts by mass of n-octyl mercaptan (n-OM) was added dropwise to the obtained copolymer latex from a dropping funnel over 50 minutes to form the third layer (thermoplastic resin component layer (IIb)). After the addition was complete, the reaction was continued at 80°C for another hour, and polymerization was terminated when it was confirmed by gas chromatography that more than 99.9% of each monomer had been consumed. The average particle size of the particles in the obtained latex, as determined by light scattering, was 100 nm.

[0081] The obtained latex was cooled at -30°C for 24 hours to induce freeze-aggregation, and the aggregate was then thawed and removed. It was dried under reduced pressure at 50°C for 2 days to obtain powdered, three-layered multilayer polymer particles (B-3). The gel content was 60%, the acetone swelling degree of the acetone-insoluble portion was 510%, and the weight-average molecular weight (Mw) of the copolymer constituting the outermost layer was 82,000. The particle structure and physical properties of the obtained multilayer polymer particles are shown in Table 1.

[0082] (Manufacturing Example 4: Manufacturing of multilayer polymer particles (B-4)) Under a nitrogen atmosphere, 100 parts by mass of distilled water, 0.019 parts by mass of surfactant (sodium polyoxyethylene alkyl ether acetate (NIKKOL-ECT-3NEX)), and 0.10 parts of sodium carbonate were added to a polymerizer equipped with a stirring blade, condenser, and dropping funnel, and heated to 80°C to dissolve uniformly. Then, at the same temperature, 0.04 parts by mass of a 3% aqueous solution of potassium peroxodisulfate was added, and a mixture consisting of 2.11 parts by mass of methyl acrylate (MA), 32.89 parts by mass of methyl methacrylate (MMA), 0.07 parts by mass of allyl methacrylate (ALMA), and 0.25 parts of surfactant (sodium polyoxyethylene alkyl ether acetate (NIKKOL-ECT-3NEX)) was added dropwise from the dropping funnel over 50 minutes to form the first layer (thermoplastic resin component layer (IIa)). After the dropwise addition was complete, the reaction was continued at 80°C for another 30 minutes, and it was confirmed by gas chromatography that more than 99% of each monomer had been consumed.

[0083] Next, 0.05 parts by mass of a 3% aqueous solution of potassium peroxodisulfate was added to the obtained copolymer latex. Then, a mixture consisting of 37.00 parts by mass of n-butyl acrylate (BA), 8.00 parts by mass of styrene (St), 0.90 parts by mass of allyl methacrylate (ALMA), and 0.012 parts of surfactant (sodium polyoxyethylene alkyl ether acetate (NIKKOL-ECT-3NEX)) was added dropwise from a dropping funnel over 60 minutes to form the second layer (rubber component layer (Ib)). After the dropwise addition was complete, the reaction was continued at 80°C for another 90 minutes, and it was confirmed by gas chromatography that more than 99% of each monomer had been consumed.

[0084] Next, 0.02 parts by mass of a 3% aqueous solution of potassium peroxodisulfate was added to the obtained copolymer latex. Then, a mixture consisting of 18.80 parts by mass of methyl methacrylate (MMA), 1.20 parts by mass of methyl acrylate (MA), and 0.04 parts by mass of n-octyl mercaptan was added dropwise from a dropping funnel over 30 minutes to form the third layer (thermoplastic resin component layer (IIb)). After the dropwise addition was complete, the reaction was continued at 80°C for another 60 minutes, and polymerization was terminated when it was confirmed by gas chromatography that more than 99.9% of each monomer had been consumed. The average particle size of the particles in the obtained latex, as determined by light scattering, was 230 nm.

[0085] The above latex was cooled at -30°C for 24 hours to induce freeze-aggregation, and the aggregate was then thawed and removed. It was dried under reduced pressure at 50°C for 2 days to obtain powdered multilayer polymer particles (B-4). The gel content was 95%, the acetone swelling degree of the acetone-insoluble portion was 320%, and the Mw of the polymer component constituting the outermost layer was 62,000. The analytical results are shown in Table 1.

[0086] [Table 1]

[0087] (Example 1) 25 parts by mass of aliphatic polyester resin (A-1) and 75 parts by mass of multilayer polymer particles (B-1) were melt-kneaded in a 20 mmφ twin-screw extruder at a cylinder temperature of 200°C, and the molten mixture was extruded to obtain a pellet-shaped resin composition (C-1). The compound composition and evaluation results are shown in Table 2.

[0088] (Examples 2-5, Comparative Examples 1-5) Resin compositions (C-2) to (C-5) and (CC-1) to (CC-5) were obtained in the same manner as in Example 1, except that the compound composition was changed as shown in Table 2. The compound compositions and evaluation results are shown in Table 2.

[0089] [Table 2]

[0090] As shown in Table 2, the resin compositions obtained in Examples 1 to 5 exhibit high tensile elongation at break and low surface hardness, as well as high biomass content and low environmental impact. On the other hand, as shown in Table 2, the resin compositions obtained in Comparative Examples 1 to 5 are outside the scope of this disclosure and have problems such as low tensile elongation at break, high surface hardness, and low biomass content, making them inferior to the disclosure.

Claims

1. A resin composition comprising 20 to 80% by mass of an aliphatic polyester resin (A) and 80 to 20% by mass of 2 to 4 layers of multilayer polymer particles (B), The multilayer polymer particle (B) has at least one rubber component layer (I) inside and at least one thermoplastic resin component layer (II) on the outermost layer. The thermoplastic resin component layer (II) is composed of a copolymer consisting of 40 to 100% by mass of methacrylic acid ester monomer units and 60 to 0% by mass of other monomer units. A resin composition in which the mass ratio (layer (I) / layer (II)) of the total amount of rubber component layer (I) to the total amount of thermoplastic resin component layer (II) is 50 / 50 to 90 / 10.

2. The resin composition according to claim 1, characterized in that the rubber component layer (I) of the multilayer polymer particles (B) is composed of a copolymer consisting of 50 to 99.99% by mass of acrylic acid ester monomer units, 49.99 to 0% by mass of other monofunctional monomer units, and 0.01 to 10% by mass of polyfunctional monomer units.

3. The resin composition according to claim 1, wherein the average particle size of the multilayer polymer particles (B) is 30 to 150 nm.

4. The resin composition according to claim 1, wherein the weight-average molecular weight of the outermost layer of the multilayer polymer particles (B) is 1,000 to 30,000.

5. The resin composition according to claim 1, wherein the acetone swelling degree of the acetone-insoluble portion of the multilayer polymer particles (B) is 500 to 1000%.

6. The resin composition according to claim 1, wherein a 1 mm thick sheet made of the resin composition has a tensile elongation at break of 50 to 400% as measured in accordance with JIS K 6251.

7. The resin composition according to claim 1, wherein the aliphatic polyester resin (A) is a polylactic acid resin.

8. The resin composition according to claim 1, wherein the biomass content is 20% or more.

9. A resin composition comprising an aliphatic polyester resin (A) and multilayer polymer particles (B) consisting of 2 to 4 layers, The content of multilayer polymer particles (B) in the resin composition (RB [mass%]), the content of the rubber component layer (I) in the multilayer polymer particles (B) (RI [mass%]), and the degree of acetone swelling of the acetone-insoluble portion of the multilayer polymer particles (B) (VA [%]) are, RB × RI × VA / 10000 ≥ 100 The resin composition according to claim 1 that satisfies the relationship.

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

11. A film comprising the resin composition according to any one of claims 1 to 9.

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