Aliphatic polyester resin composition and catalyst master batch

Abstract

Provided is a biodegradable resin material which imparts a finished product such as a motor vehicle or a cellular phone with lightness and high strength. Provided are: a resin composition that contains a thermoplastic resin (A) that is reactive with an aliphatic polyester and an epoxy group, an epoxy group-containing thermoplastic resin (B), and at least one catalyst (C) selected from among a transesterification catalyst and an epoxy ring-opening catalyst; and a catalyst master batch that contains a thermoplastic resin (D) not having an epoxy group and at least one catalyst (C) selected from among a transesterification catalyst and an epoxy ring-opening catalyst.

Description

Aliphatic polyester resin composition and catalyst masterbatch

[0001] The present invention relates to an aliphatic polyester resin composition and a catalyst masterbatch.

[0002] In recent years, biodegradable polymers that decompose in the natural environment have attracted attention and are being studied worldwide in order to protect the global environment. Aliphatic polyesters such as polylactic acid, polyhydroxybutyrate, and polycaprolactone are known as biodegradable polymers. Among these, polylactic acid, in particular, is a highly biosafe and environmentally friendly polymeric material because it is made from lactic acid or its derivatives obtained from biological sources. Therefore, its use as a general-purpose polymer, including in stretched films, fibers, and injection-molded products, is being considered.

[0003] However, polylactic acid resins are brittle and hard, limiting their applications, and have hardly been used in fields such as daily necessities, home appliance parts, and automobile parts. Even when they are molded into injection-molded articles, they suffer from problems such as insufficient mechanical strength, such as insufficient flexibility and impact resistance, and are therefore not currently used. Furthermore, polylactic acid has a low crystallization rate and a slow molding cycle, resulting in poor productivity, significantly limiting the scope of its practical application.

[0004] Patent Document 1 discloses a resin composition containing a polyolefin resin, a biodegradable resin (aliphatic polyester-based biodegradable polymer), and an acid- or epoxy-group-containing polyolefin. Patent Document 1 states that the use of an acid- or epoxy-group-containing polyolefin makes it possible to provide a composition and molded article having an excellent balance of physical properties such as processability, impact resistance, and elastic modulus. However, the resin composition described in Patent Document 1 requires multiple kneading sections, making the manufacturing method complicated, and the mechanical strength of the resulting molded article not meeting the desired level.

[0005] Japanese Patent Application Laid-Open No. 2006-077063

[0006] An object of the present invention is to provide a thermoplastic resin composition that provides molded articles having excellent mechanical strength, particularly impact resistance. This thermoplastic resin composition is suitable for forming molded articles that require high impact resistance, such as components for vehicles, ships, electronic devices, home appliances, and building materials, as well as daily necessities, sporting goods, and stationery. Furthermore, the thermoplastic resin used in the present invention is a biomass plastic derived from plants, etc., and is preferably used as a resin molded article with low environmental impact.

[0007] The present invention includes the following inventions. [1] A resin composition comprising a thermoplastic aliphatic polyester resin (A) reactive with epoxy groups, a thermoplastic resin (B) having epoxy groups, and a catalyst (C) which is at least one selected from a transesterification catalyst and an epoxy ring-opening catalyst. [2] The resin composition according to [1], which comprises 0.5 to 20 parts by weight of a thermoplastic resin (B) having epoxy groups and 0.0001 to 2 parts by weight of the catalyst (C) per 100 parts by weight of the thermoplastic resin (A). [3] The resin composition according to [1], wherein the thermoplastic resin (A) is a polymer of an aliphatic hydroxycarboxylic acid having 2 to 10 carbon atoms. [4] The resin composition according to [1], wherein the thermoplastic resin (B) having epoxy groups has at least one epoxy group in the polymer. [5] The resin composition according to [1], wherein the catalyst (C) catalyzes the reaction between the thermoplastic resin (A) and the thermoplastic resin (B) having an epoxy group, and the catalyst (C) is at least one catalyst selected from the group consisting of alkali metal compounds, alkaline earth metal compounds, titanium compounds, antimony compounds, germanium compounds, manganese compounds, tin compounds, aluminum compounds, bismuth compounds, gallium compounds, indium compounds, zinc compounds, nitrogen-containing compounds, basic phosphorus compounds, phosphorous compounds, basic ammonium compounds, and amine compounds. [6] A catalyst masterbatch comprising a thermoplastic resin (D) having no epoxy groups, and a catalyst (C) which is at least one selected from the group consisting of a transesterification catalyst and an epoxy ring-opening catalyst, wherein the amount of the catalyst (C) is 0.05 to 10% by weight based on the total weight of the thermoplastic resin (D) having no epoxy groups and the catalyst (C). [7] The catalyst masterbatch according to [6], wherein the thermoplastic resin (D) having no epoxy groups is a polyethylene and ethylene copolymer, or is compatible or miscible with the thermoplastic resin (B) having epoxy groups and has a structure similar to that of (B). [8] The catalyst masterbatch according to [6], wherein the thermoplastic resin (D) having no epoxy groups is a thermoplastic aliphatic polyester resin reactive with epoxy groups. [9] A method for producing the catalyst masterbatch according to [6], comprising mixing the thermoplastic resin (D) having no epoxy groups with the catalyst (C).

[10] The resin composition according to [1], wherein the thermoplastic resin (A), the thermoplastic resin (B) having epoxy groups, and the catalyst (C) are each in a particulate form.

[11] The impact-modified resin composition according to [1], obtained by melt-kneading the thermoplastic resin (A), the thermoplastic resin (B) having epoxy groups, and the catalyst (C).

[0008] A resin composition containing a thermoplastic aliphatic polyester resin reactive with epoxy groups, a thermoplastic resin having epoxy groups, and at least one catalyst selected from a transesterification catalyst and an epoxy ring-opening catalyst has good masterbatch dispersibility and significantly high impact strength.

[0009] The resin composition comprises: (A) a thermoplastic aliphatic polyester resin reactive with epoxy groups; (B) a thermoplastic resin having epoxy groups; and (C) a catalyst selected from the group consisting of a transesterification catalyst and an epoxy ring-opening catalyst. The catalyst (C) may be in the form of a catalyst masterbatch (E).

[0010] The catalyst masterbatch (E) comprises: (D) a thermoplastic resin having no epoxy groups; and (C) a catalyst which is at least one selected from a transesterification catalyst and an epoxy ring-opening catalyst.

[0011] <(A) Aliphatic polyester and thermoplastic resin reactive with epoxy groups> Aliphatic polyester is a biomass-derived or biodegradable thermoplastic resin. Furthermore, "biodegradable" means that it can be decomposed by microorganisms, enzymes, etc. in the natural environment. The biodegradability of a resin is thought to depend on the chemical structure of the resin. For example, it is thought that at least one factor in the biodegradability of a resin is the change of groups in the chemical structure of the resin, such as ester bonds, carbamoyl bonds, and carbamic acid esters that undergo hydrolysis, halogen substituents and ether bonds that undergo reduction, and vinyl groups, phenyl groups, and branched alkanes that undergo oxidation.

[0012] The thermoplastic resin (A) is an aliphatic polyester resin. The aliphatic polyester resin is not particularly limited, and examples thereof include a polymer having an aliphatic hydroxycarboxylic acid as the main component, and a polymer having an aliphatic polycarboxylic acid and an aliphatic polyhydric alcohol as the main components.

[0013] The aliphatic hydroxycarboxylic acid may have 2 to 10, 3 to 8, or 3 to 6 carbon atoms, and the number of hydroxy groups may be 1 to 3, particularly 1. In the aliphatic polycarboxylic acid and the aliphatic polyhydric alcohol, the aliphatic polycarboxylic acid may have 2 to 10, 3 to 8, or 4 to 6 carbon atoms, the aliphatic polycarboxylic acid may have 2 to 6 or 2 to 4, particularly 2 carboxyl groups, the aliphatic polyhydric alcohol may have 2 to 10, 3 to 8, or 4 to 6 carbon atoms, and the aliphatic polyhydric alcohol may have 2 to 6 or 2 to 4, particularly 2 hydroxyl groups.

[0014] Specific examples of aliphatic polyester resins include polyglycolic acid, polylactic acid, polylactic acid / polyether copolymer, butanediol / long-chain dicarboxylic acid copolymer, polybutylene succinate adipate, poly3-hydroxybutyric acid, poly4-hydroxybutyric acid, poly4-hydroxyvaleric acid, poly3-hydroxyhexanoic acid, polycaprolactone, polyethylene adipate, polyethylene succinate, polybutylene adipate, and polybutylene succinate. These aliphatic polyesters can be used alone or in combination of two or more. Among these aliphatic polyesters, polymers containing hydroxycarboxylic acid as the main constituent are preferred, and polylactic acid resins are particularly preferred.

[0015] The thermoplastic resin (A) may be a single resin or a combination of at least two types. The amount of the thermoplastic resin (A) in the resin composition is 100 parts by weight.

[0016] Alternatively, the amount of thermoplastic resin (A) may be 60% by weight or more, 65% by weight or more, 70% by weight or more, 75% by weight or more, 80% by weight or more, 85% by weight or more, 90% by weight or more, or 95% by weight or more, and may be 99% by weight or less, 98% by weight or less, 97% by weight or less, 95% by weight or less, 92% by weight or less, 90% by weight or less, 88% by weight or less, or 85% by weight or less, based on the resin composition.

[0017] <(B) Thermoplastic Resin Having Epoxy Group> The epoxy group in the thermoplastic resin (B) having an epoxy group reacts with a site in the thermoplastic resin (A) that reacts with the epoxy group.

[0018] The thermoplastic resin (B) having an epoxy group is a copolymer (e.g., a graft polymer) having a monomer unit derived from a monomer having an epoxy group and a monomer unit derived from ethylene. Examples of the monomer having an epoxy group include α,β-unsaturated glycidyl esters such as glycidyl methacrylate and glycidyl acrylate, and α,β-unsaturated glycidyl ethers such as allyl glycidyl ether and 2-methylallyl glycidyl ether, with glycidyl methacrylate being preferred. Polymers modified with a modifier (e.g., an acrylic modifier) ​​are also included.

[0019] The thermoplastic resin (B) having an epoxy group may have, in addition to the monomer units derived from a monomer having an epoxy group and the monomer units derived from ethylene, monomer units derived from other monomers, and examples of the other monomers include unsaturated carboxylic acid esters such as methyl acrylate, ethyl acrylate, methyl methacrylate, and butyl acrylate, and unsaturated vinyl esters such as vinyl acetate and vinyl propionate.

[0020] The thermoplastic resin (B) having an epoxy group may contain a rubber component in addition to the monomer units derived from the epoxy group-containing monomer and the monomer units derived from ethylene. The type of rubber component is not particularly limited, as long as it is composed of a polymer component having rubber elasticity. Examples of polymer components having rubber elasticity include rubbers composed of polymerized acrylic components, silicone components, styrene components, nitrile components, conjugated diene components, urethane components, or ethylene-propylene components. For example, rubbers composed of polymerized acrylic components such as ethyl acrylate units or butyl acrylate units, silicone components such as dimethylsiloxane units or phenylmethylsiloxane units, styrene components such as styrene units or α-methylstyrene units, nitrile components such as acrylonitrile units or methacrylonitrile units, or conjugated diene components such as butadiene units or isoprene units. Rubbers formed by copolymerizing two or more of these components may also be used, including rubbers formed by copolymerizing an acrylic component such as ethyl acrylate units or butyl acrylate units with a silicone component such as dimethylsiloxane units or phenylmethylsiloxane units, rubbers formed by copolymerizing an acrylic component such as ethyl acrylate units or butyl acrylate units with a styrene component such as styrene units or α-methylstyrene units, rubbers formed by copolymerizing an acrylic component such as ethyl acrylate units or butyl acrylate units with a conjugated diene component such as butadiene units or isoprene units, and rubbers formed by copolymerizing an acrylic component such as ethyl acrylate units or butyl acrylate units with a silicone component such as dimethylsiloxane units or phenylmethylsiloxane units with a styrene component such as styrene units or α-methylstyrene units. Furthermore, rubbers formed by copolymerizing a crosslinkable component such as divinylbenzene units, allyl acrylate units, or butylene glycol diacrylate units and crosslinking the copolymerized components may also be used.

[0021] The thermoplastic resin (B) having an epoxy group may be a single resin or a combination of at least two types. The content of monomer units derived from a monomer having an epoxy group is preferably 0.01 to 30% by weight, more preferably 0.1 to 20% by weight, where the content of all monomer units in the ethylene polymer having an epoxy group is taken as 100% by weight.

[0022] Alternatively, the amount of the thermoplastic resin (B) having an epoxy group may be 0.3% by weight or more, 0.5% by weight or more, 1% by weight or more, 2% by weight or more, 3% by weight or more, 5% by weight or more, 8% by weight or more, or 10% by weight or more, and may be 30% by weight or less, 20% by weight or less, 15% by weight or less, 10% by weight or less, 5% by weight or less, 3% by weight or less, 2% by weight or less, or 1% by weight or less, based on the resin composition.

[0023] <Catalyst (C)> The catalyst (C) is at least one selected from a transesterification catalyst and an epoxy ring-opening catalyst. The catalyst (C) may be either a transesterification catalyst or an epoxy ring-opening catalyst, or may be both a transesterification catalyst and an epoxy ring-opening catalyst. The catalyst (C) promotes the reaction between the polyester and the epoxy. Examples of the catalyst (C) include alkali metal (e.g., sodium, potassium) compounds, alkaline earth metal (e.g., magnesium, calcium, barium) compounds, titanium compounds, antimony compounds, germanium compounds, manganese compounds, tin compounds, aluminum compounds, bismuth compounds, gallium compounds, indium compounds, zinc compounds, nitrogen-containing compounds (e.g., imidazole), basic phosphorus compounds, phosphorous compounds, basic ammonium compounds, and amine compounds.

[0024] The catalyst (C) may be an organic or inorganic compound.

[0025] The catalyst (C) is preferably a metal compound. The metal compound may be, for example, an alkoxide, an organic acid salt (e.g., an acetate), an inorganic acid salt (e.g., a borate), a metal oxide, or a hydrate thereof. The metal compound may be a titanium compound (e.g., tetra-n-propyl titanate), an antimony compound (e.g., antimony trioxide, antimony acetate), a germanium compound (e.g., germanium dioxide), or a tin compound (e.g., tin dioxide). Antimony trioxide, antimony acetate, and germanium dioxide are particularly preferred.

[0026] The catalyst (C) may be an organic compound, and the organic compound is a nitrogen-containing compound (e.g., imidazole), an amine compound, etc. The amine compound is not particularly limited, but may be an aliphatic amine, an aromatic amine, an amino alcohol, an amino acid, or a combination of two or more of these.

[0027] The catalyst (C) may be used alone or in combination of at least two types. The amount of catalyst (C) in the catalyst masterbatch (E) may be 0.01 to 10 parts by weight, 0.1 to 8 parts by weight, or 0.2 to 5 parts by weight, relative to 100 parts by weight of the thermoplastic resin (D) having no epoxy groups. Alternatively, the amount of catalyst (C) may be 0.01 to 50% by weight, 0.1 to 30% by weight, 0.2 to 10% by weight, or 0.5 to 5% by weight, relative to the total of the thermoplastic resin (D) having no epoxy groups and the catalyst (C).

[0028] The catalyst (C) may be used alone or in combination of at least two kinds. The amount of (C) may be 1 to 100,000 ppm, 2 to 50,000 ppm, 5 to 10,000 ppm, 10 to 5,000 ppm, or 50 to 1,000 ppm, based on the resin composition.

[0029] <(D) Thermoplastic Resin Having No Epoxy Group> The thermoplastic resin (D) having no epoxy group may or may not have a site reactive with an epoxy group. Generally, the thermoplastic resin (D) having no epoxy group does not have a site reactive with an epoxy group.

[0030] The thermoplastic resin (D) having no epoxy group may be a copolymer having a repeating unit derived from ethylene and a unit derived from vinyl acetate or a methacrylate ester.

[0031] In the olefin copolymer, examples of the monomer other than the olefin include unsaturated carboxylic acid esters such as methyl acrylate, ethyl acrylate, methyl methacrylate, and butyl acrylate, and unsaturated vinyl esters such as vinyl acetate and vinyl propionate.

[0032] The thermoplastic resin (D) having no epoxy group may contain units derived from vinyl acetate, methacrylic acid ester, etc. The amount of the units derived from vinyl acetate, methacrylic acid ester, etc. is 0.01% by weight to 50% by weight, preferably 0.1% by weight to 30% by weight, based on the thermoplastic resin (D) having no epoxy group.

[0033] The thermoplastic resin (D) having no epoxy groups is preferably compatible or miscible with the thermoplastic resin (B) having epoxy groups. Furthermore, the thermoplastic resin (D) having no epoxy groups preferably has a similar structure to the thermoplastic resin (B) having epoxy groups. "Similar structure" means a resin having the same monomer unit. For example, the thermoplastic resin (D) having no epoxy groups and the thermoplastic resin (B) having epoxy groups correspond to a homopolymer, copolymer, blend, or graft product having the same monomer unit.

[0034] The thermoplastic resin (D) not having an epoxy group may also be an aliphatic polyester or the like as described for the thermoplastic resin (A).

[0035] The thermoplastic resin (D) having no epoxy group may be a single resin or a combination of at least two types. The amount of the thermoplastic resin (D) having no epoxy group is 100 parts by weight in the transesterification catalyst and epoxy ring-opening catalyst masterbatch (E).

[0036] <(E) Catalyst Masterbatch> The catalyst masterbatch (E) comprises: (D) a thermoplastic resin having no epoxy group; and (C) a catalyst which is at least one selected from a transesterification catalyst and an epoxy ring-opening catalyst.

[0037] The catalyst masterbatch (E) may be used alone or in combination of at least two types. The amount of the catalyst masterbatch (E) may be 0.01 to 20 parts by weight, 0.1 to 15 parts by weight, or 1 to 10 parts by weight, relative to 100 parts by weight of the biodegradable, epoxy group-reactive thermoplastic resin (A) in the resin composition. Alternatively, the amount of the catalyst masterbatch (E) may be 0.01% by weight or more, 0.05% by weight or more, 0.1% by weight or more, 0.5% by weight or more, 1% by weight or more, 2% by weight or more, 3% by weight or more, or 5% by weight or more, relative to the resin composition, and may be 30% by weight or less, 20% by weight or less, 15% by weight or less, 10% by weight or less, 5% by weight or less, 3% by weight or less, 2% by weight or less, or 1% by weight or less.

[0038] <Other Components> The resin composition and masterbatch may contain other components. Examples of other components, such as additives, include neutralizing agents, antioxidants, UV absorbers, lubricants, antistatic agents, antiblocking agents, processing aids, colorants (inorganic pigments, organic pigments, pigment dispersants, etc.), foaming agents, nucleating agents, plasticizers, flame retardants, brightness enhancers, antibacterial agents, and light diffusing agents. These additives may be used alone or in combination of two or more. The additives may be present in an amount of 50% by weight or less, 0.1 to 30% by weight, or 1 to 20% by weight relative to the resin composition or masterbatch.

[0039] <Method for Producing Masterbatch> The masterbatch can be produced by melt-mixing a thermoplastic resin (A) reactive with an epoxy group or a thermoplastic resin (D) not having an epoxy group with a catalyst (C).

[0040] The components constituting the masterbatch (epoxy-free thermoplastic resin (D), catalyst (C), and other components as needed) are blended in a predetermined blending ratio in various forms such as bulk, pellets, or chips, and then, after premixing as needed, placed in a melt kneader and heated to or above the melting point of the epoxy-free thermoplastic resin (D) to melt-knead. The mixture is then extruded into a strand and cut into granules (pellets or chips) to obtain the masterbatch. The size (maximum length) may generally be 0.1 to 100 mm or 0.5 to 50 mm.

[0041] The premixing may be dry blending using a premixer such as a ribbon blender, a Henschel mixer, or a V blender. The melt-kneading may be performed using a melt-kneader equipped with a heating mechanism, such as a Banbury mixer, a mixing roll, a single-screw or twin-screw extruder, or a kneader. The melt-kneader may be equipped with a filter having an opening of 1 mm or less, for example, 0.01 to 0.5 mm, particularly 0.05 to 0.3 mm.

[0042] <Method for producing resin composition> The resin composition can be produced by premixing the catalyst (C), the thermoplastic resin (A) having a site reactive with an epoxy group, and the thermoplastic resin (B) having an epoxy group, as needed, followed by melt-kneading.

[0043] The temperature for melt-kneading is equal to or higher than the melting points of the thermoplastic resin (D) having no epoxy groups, the thermoplastic resin (A) having a site reactive with an epoxy group, and the thermoplastic resin (B) having an epoxy group (a temperature higher than the highest melting point of these resins) so that these resins are melted. In the premixing and melt-kneading, a premixer and melt-kneader similar to those used in the method for producing a masterbatch may be used.

[0044] EXAMPLES The present invention will be specifically explained below with reference to examples and comparative examples, but the present invention is not limited to these examples.

[0045] The test methods, raw materials and manufacturing methods used below are as follows:

[0046] [Raw materials] Thermoplastic resin having a site reactive with an epoxy group (A) A-1: ​​Luminy (registered trademark) LX-575 manufactured by Total Corbion Thermoplastic resin having an epoxy group (B) B-1: Bondfast (registered trademark) BF-E manufactured by Sumitomo Chemical Co., Ltd. Catalyst (C) C-1: Antimony trioxide C-2: Antimony trioxide C-3: Germanium dioxide C-4: Antimony acetate Thermoplastic resin not having an epoxy group (D) D-1: Acryft (registered trademark) WD201-F manufactured by Sumitomo Chemical Co., Ltd. Catalyst masterbatch (E) E-1: Masterbatch containing 2.0% by weight of antimony trioxide E-2: Masterbatch containing 5.0% by weight of antimony trioxide E-3: Masterbatch containing 5.0% by weight of germanium dioxide E-4: Masterbatch containing 5.0% by weight of antimony acetate

[0047] [Charpy Impact Test] Test specimens for evaluating physical properties were prepared under the following injection molding conditions. The pellets of the resin composition obtained above were injection molded using an IS80EPN-2A injection molding machine manufactured by Shibaura Machine Co., Ltd., at a molding temperature of 190 to 200°C, a mold cooling temperature of 35°C, an injection time of 15 seconds, and a cooling time of 60 seconds. The obtained injection molded body was aged at 120°C for 4 hours or more in a hot air circulation thermostatic oven to prepare a molded body. The prepared molded body was then notched to a width of 10 mm, a thickness of 4 mm, and a notch height of 8 mm. The prepared test specimens were evaluated in accordance with ISO 179 using an IT-type impact tester manufactured by Toyo Seiki Seisakusho Co., Ltd.

[0048] [Intrinsic Viscosity] 25 mL of chloroform and 0.125 g of the resin composition were placed in a measuring flask and dissolved. The viscosity of the prepared solution at 25°C was measured using an Ostwald viscometer. The viscosity of the solvent was also measured in the same manner. Using the obtained solution viscosity and solvent viscosity, [η] was calculated from the following formula (α), and the obtained value was taken as the intrinsic viscosity. [η] = (-1 + (1 + 4K'η ｓｐ ) １／２ ) / 2K'C where η ｓｐ = (solution viscosity / solvent viscosity)-1, K' is Huggins' constant (PLA = 0.636), C = polymer weight per 100 mL.

[0049] [Crystallization Temperature] 10 mg of the resin composition was filled into an aluminum cell, and using a differential scanning calorimeter (DSCvesta Smartloader manufactured by Rigaku Corporation), the temperature was raised from room temperature to 200°C at a rate of 5°C / min, and then lowered from 200°C to 25°C at a rate of 1°C / min, and the crystallization peak temperature during temperature lowering was measured.

[0050] [Cooling Time] Pellets of the resin composition were injection molded using an injection molding machine EC75SX3-1.5A manufactured by Shibaura Machine Co., Ltd. at a molding temperature of 190 to 200°C, a mold cooling temperature of 110°C, and an injection time of 15 seconds. The cooling time until the molded article could be easily removed from the mold and no distortion or bending occurred in the shape of the molded article was compared.

[0051] [Example 1] (Masterbatch Production Example) A masterbatch was produced using a twin-screw kneading extruder by supplying 70% by weight of a thermoplastic resin (D-1) not having an epoxy group and 30% by weight of a catalyst (C-1) and melt-kneading the mixture. The produced masterbatch was then diluted with the thermoplastic resin (D-1) not having an epoxy group to obtain a masterbatch (E-1) containing 2.0% by weight of antimony trioxide. (Resin Composition Production Example) A twin-screw kneading extruder was used to supply raw materials in the mixing ratios shown in Table 1 and melt-knead the materials. The cylinder temperature was set to 50 to 190°C, and the extrusion rate was 30 kg / h, with the screw rotation speed at 400 rpm, to produce a resin composition.

[0052] [Examples 2 to 4 and Comparative Examples 1 and 2] Masterbatches (E-2 to E-4) and resin compositions were produced in the same manner as in Example 1, except that the type and amount of catalyst were changed as shown in Table 1 or Table 2. The resin compositions were subjected to a Charpy impact test, intrinsic viscosity measurement, crystallization temperature measurement, and cooling time measurement during molding.

[0053] Examples 1 to 4 and Comparative Examples 1 and 2 are shown in Tables 1 and 2 below.

[0054]

[0055]

[0056] The thermoplastic aliphatic polyester resin composition of the present invention is suitable for forming molded articles requiring high impact resistance, such as components for vehicles, ships, electronic devices, home appliances, building materials, etc., as well as daily necessities, sporting goods, stationery, etc. Furthermore, polylactic acid is one of the representative thermoplastic aliphatic polyester resins, and can be used as a resin molded article with low environmental impact from the viewpoint of carbon neutrality.

Claims

1. A resin composition comprising a thermoplastic aliphatic polyester resin (A) having reactivity with an epoxy group, a thermoplastic resin (B) having an epoxy group, and a catalyst (C) which is at least one selected from a transesterification catalyst and an epoxy ring-opening catalyst, the catalyst (C) is at least one catalyst selected from the group consisting of alkaline earth metal compounds, titanium compounds, antimony compounds, germanium compounds, manganese compounds, tin compounds, aluminum compounds, bismuth compounds, gallium compounds, indium compounds, zinc compounds, nitrogen-containing compounds, basic phosphorus compounds, phosphorous compounds, basic ammonium compounds, and amine compounds; A resin composition in which the amount of catalyst (C) is 50 ppm to 2 parts by weight based on the resin composition.

2. 2. The resin composition according to claim 1, comprising 0.5 to 20 parts by weight of a thermoplastic resin (B) having an epoxy group and 0.0001 to 2 parts by weight of a catalyst (C) relative to 100 parts by weight of the thermoplastic resin (A).

3. 2. The resin composition according to claim 1, wherein the thermoplastic resin (A) is a polymer of an aliphatic hydroxycarboxylic acid having 2 to 10 carbon atoms.

4. 2. The resin composition according to claim 1, wherein the thermoplastic resin (B) having an epoxy group has at least one epoxy group in the polymer.

5. the catalyst (C) catalyzes the reaction between the thermoplastic resin (A) and the thermoplastic resin (B) having an epoxy group; 2. The resin composition according to claim 1, wherein the catalyst (C) is at least one catalyst selected from the group consisting of alkoxides, organic acid salts, inorganic acid salts, metal oxides, basic phosphorus compounds, and hydrates thereof.

6. A thermoplastic resin (D) having no epoxy groups, and a catalyst (C) which is at least one selected from a transesterification catalyst and an epoxy ring-opening catalyst; A catalyst masterbatch comprising: the catalyst (C) is at least one catalyst selected from the group consisting of alkaline earth metal compounds, titanium compounds, antimony compounds, germanium compounds, manganese compounds, tin compounds, aluminum compounds, bismuth compounds, gallium compounds, indium compounds, zinc compounds, nitrogen-containing compounds, basic phosphorus compounds, phosphorous compounds, basic ammonium compounds, and amine compounds; A catalyst masterbatch in which the amount of the catalyst (C) is 0.05 to 10% by weight based on the total weight of the thermoplastic resin (D) having no epoxy group and the catalyst (C).

7. 7. The catalyst masterbatch according to claim 6, wherein the thermoplastic resin (D) having no epoxy groups is a polyethylene or ethylene copolymer, or is compatible or soluble with the thermoplastic resin (B) having epoxy groups and has a structure similar to that of (B).

8. 7. The catalyst masterbatch according to claim 6, wherein the thermoplastic resin (D) having no epoxy group is a thermoplastic aliphatic polyester resin reactive with an epoxy group.

9. 7. A method for producing a catalyst masterbatch according to claim 6, comprising mixing a thermoplastic resin (D) having no epoxy group with the catalyst (C).

10. 2. The resin composition according to claim 1, wherein the thermoplastic resin (A), the thermoplastic resin having an epoxy group (B), and the catalyst (C) are each in a particulate form.

11. The impact-modified resin composition according to claim 1, obtained by melt-kneading a thermoplastic resin (A), a thermoplastic resin (B) having an epoxy group, and a catalyst (C).

12. 2. The resin composition according to claim 1, wherein the thermoplastic resin (B) having an epoxy group is a copolymer having a monomer unit derived from a monomer having an epoxy group and a monomer unit derived from ethylene.

13. 7. The catalyst masterbatch according to claim 6, wherein the thermoplastic resin (D) having no epoxy groups has no sites reactive with epoxy groups.

14. 7. The catalyst masterbatch according to claim 6, wherein the thermoplastic resin (D) having no epoxy group is a copolymer having a repeating unit derived from ethylene and a repeating unit derived from at least one selected from vinyl acetate and methacrylic acid ester.