Resin composition and biodegradable resin molded product comprising same

Abstract

The present invention relates to a resin composition and a biodegradable resin molded product comprising same. The resin composition of the present invention can implement excellent mechanical properties while maintaining biodegradability of polybutylene adipate terephthalate.

Description

Resin composition and biodegradable resin molded article comprising the same

[0001] Cross-citation with related application(s)

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2024-0148909 filed on October 28, 2024, and all contents disclosed in the literature of said Korean patent applications are incorporated herein as part of this specification.

[0003]

[0004] The present invention relates to a resin composition and a biodegradable resin molded article comprising the same.

[0005]

[0006] With the recent surge in interest in environmental protection and eco-friendliness, the need for methods to cultivate eco-friendly agricultural products is increasing. Mulching is known as one such eco-friendly farming method; it involves covering the soil surface with mulching film during crop cultivation to prevent weed growth and pest infestations, maintain soil moisture or regulate soil temperature, prevent soil erosion caused by rainwater, and reduce the use of pesticides.

[0007]

[0008] While mulching films used in such farming methods significantly contribute to agricultural productivity, they present challenges regarding collection and recycling after use. Typically, synthetic resins such as polypropylene and polyethylene are used, and although biodegradable components are added as additives to impart biodegradability, the synthetic resins themselves are currently unable to biodegrade. Furthermore, the synthetic resins remaining without biodegradation pose a problem of soil contamination.

[0009]

[0010] In addition to the mulching films for crop cultivation mentioned above, various studies are underway to replace synthetic resins with biodegradable resins as environmental issues such as microplastics in conventional synthetic resins, human safety concerns such as endocrine disruptors, and the depletion of natural resources used as raw materials for plastics have emerged. Notably, the application of biodegradable resins is required in diverse fields, including food packaging, drinking water containers, food containers, and automotive molded parts.

[0011]

[0012] Therefore, there have been attempts to manufacture mulching films using polybutylene adipate terephthalate (PBAT), a biodegradable plastic. However, while polybutylene adipate terephthalate (PBAT) has high elongation, it has the problem of having lower mechanical properties, such as Young's modulus, compared to conventional films such as polyethylene. Additionally, since polybutylene adipate terephthalate (PBAT) is a 100% petroleum-based material, it has a low bio-raw material content.

[0013]

[0014] Accordingly, attempts have been made to improve physical properties and increase the bio-material content by compounding various biodegradable materials with polybutylene adipate terephthalate (PBAT); however, there is a problem of poor mechanical properties due to low compatibility between polybutylene adipate terephthalate and other biodegradable materials.

[0015]

[0016] The present invention aims to provide a resin composition that exhibits high biodegradability and has improved mechanical properties through enhanced compatibility between biodegradable resins.

[0017] In addition, the present invention aims to provide a resin molded article comprising the above resin composition.

[0018]

[0019] To solve the above problem, the present invention provides a resin composition comprising polybutylene adipate terephthalate (PBAT); polylactic acid (PLA); thermoplastic starch (TPS); and a compatibilizer, wherein the compatibilizer comprises a polyolefin elastomer grafted with maleic anhydride.

[0020]

[0021] According to one example, the polylactic acid may be included in an amount of 0.1 to 20 parts by weight with respect to a total of 100 parts by weight of the polybutylene adipate terephthalate, polylactic acid, and thermoplastic starch.

[0022]

[0023] According to one example, the thermoplastic starch may be included in an amount of 20 to 50 parts by weight relative to a total of 100 parts by weight of the polybutylene adipate terephthalate, polylactic acid, and thermoplastic starch.

[0024]

[0025] According to one example, the polyolefin elastomer may include one or more selected from the group consisting of polypropylene elastomer, polyethylene elastomer, polyethylenepropylene elastomer, ethylene-propylene-diene monomer elastomer, polyethylene-1-pentene elastomer, polyethylene-1-hexene elastomer, polyethylene-1-heptene elastomer, and polyethylene-1-octene elastomer.

[0026]

[0027] According to one example, the graft rate of the maleic anhydride-grafted polyolefin elastomer may be 0.1 weight% to 2.0 weight%.

[0028]

[0029] According to one example, the polyolefin elastomer grafted with maleic anhydride may be included in an amount of 0.01 to 2.0 parts by weight with respect to a total of 100 parts by weight of the polybutylene adipate terephthalate, polylactic acid, and thermoplastic starch.

[0030]

[0031] According to one example, the resin composition of the present invention may comprise, based on a total of 100 parts by weight of polybutylene adipate terephthalate, polylactic acid, and thermoplastic starch, 40 to 79 parts by weight of polybutylene adipate terephthalate, 0.1 to 20 parts by weight of polylactic acid, 20 to 50 parts by weight of thermoplastic starch, 0.01 to 2.0 parts by weight of a polyolefin elastomer grafted with maleic anhydride, and 0.1 to 0.5 parts by weight of a slip agent.

[0032]

[0033] According to one example, the above compatibilizer may further include polybutylene adipate terephthalate in which maleic acid is ester-bonded to the terminal hydroxyl group.

[0034] According to one example, the viscosity of polybutylene adipate terephthalate in which maleic acid is ester-bonded to the hydroxyl group at the end may be 500 Pa.s to 5,000 Pa.s.

[0035] According to one example, the polybutylene adipate terephthalate in which maleic acid is ester-bonded to the terminal hydroxyl group may contain 1.0% to 10.0% by weight of maleic acid.

[0036] According to one example, the weight-average molecular weight of polybutylene adipate terephthalate in which maleic acid is ester-bonded to the terminal hydroxyl group may be 100,000 g / mol to 150,000 g / mol.

[0037] According to one example, based on the total weight of the polybutylene adipate terephthalate, polylactic acid, thermoplastic starch, and polybutylene adipate terephthalate in which maleic acid is ester-bonded to the terminal hydroxyl group, the composition may include 0.1 to 10 weight% of polybutylene adipate terephthalate in which maleic acid is ester-bonded to the terminal hydroxyl group.

[0038]

[0039] In addition, the present invention provides a resin molded article comprising the resin composition of the present invention.

[0040]

[0041] According to one example, the resin molded article has a tensile strength value of 200 kgf / cm² as measured according to ISO 527 standards. 2 Up to 500 kgf / cm² 2 It could be.

[0042]

[0043] According to one example, the resin molded article may have an elongation value of 350% to 1000% as measured according to ISO 527 standards.

[0044]

[0045] According to one example, the resin molded article may have a Dart impact of 400 g or more and 2.5 J or more as measured according to ASTM D1709 standards.

[0046]

[0047] According to one example, the resin molded article may have a Puncture resistance value of 15.0 N or more, 70.0% or more, and 0.70 J or more as measured according to ASTM D5748 standards.

[0048]

[0049] According to one example, the resin molded article may be a biodegradable mulching film or a food packaging film.

[0050]

[0051] The terms used in this specification are used merely to describe exemplary embodiments and are not intended to limit the invention.

[0052] A singular expression includes a plural expression unless the context clearly indicates otherwise.

[0053] In this specification, terms such as “comprising,” “comprising,” or “having” are used to describe features, numbers, steps, components, or combinations thereof that are implemented, and do not exclude one or more other features, numbers, steps, components, combinations thereof, or the possibility of addition.

[0054] The present invention is capable of various modifications and may take various forms, and specific embodiments are illustrated and described in detail below. However, this is not intended to limit the invention to the specific disclosed forms, and it should be understood that the invention includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the invention.

[0055]

[0056] The present invention will be described in detail below.

[0057]

[0058] The present invention provides a resin composition comprising polybutylene adipate terephthalate (PBAT); polylactic acid (PLA); thermoplastic starch (TPS); and a compatibilizer, wherein the compatibilizer comprises a polyolefin elastomer grafted with maleic anhydride.

[0059]

[0060] PBAT is a biodegradable polymer that exhibits high elongation at break and ductility. However, its applications are limited due to low mechanical properties, such as tensile strength and elastic modulus. To overcome these limitations, the range of applications and properties can be improved by mixing PBAT with other biodegradable polymers.

[0061]

[0062] Representative biodegradable polymers blendable with PBAT include polylactic acid and thermoplastic starch. However, when preparing a resin composition by compounding polybutylene adipate terephthalate (PBAT), a type of biodegradable resin, with polylactic acid and thermoplastic starch, there is a problem of reduced compatibility because PBAT exhibits hydrophobic properties while thermoplastic starch exhibits hydrophilic properties, which ultimately degrades the mechanical properties of the compound resin.

[0063]

[0064] Accordingly, the inventors of the present invention completed the invention by confirming that when a polyolefin elastomer grafted with maleic anhydride is included as a compatibilizer for a composition comprising polybutylene adipate terephthalate, polylactic acid, and thermoplastic starch, compatibility is improved and the mechanical properties of a resin molded article produced from the resin composition are improved.

[0065]

[0066] The resin composition of the present invention comprises the polybutylene adipate terephthalate (PBAT) as a biodegradable resin. The polybutylene adipate terephthalate may be included in an amount of 40 to 79 parts by weight per 100 parts by weight of the total resin composition, and more specifically, may be included in an amount of 42 parts by weight or more, 45 parts by weight or more, or 50 parts by weight or more, or 79 parts by weight or less, 75 parts by weight or less, 74 parts by weight or less, 73 parts by weight or less, 72 parts by weight or less, 71 parts by weight or less, or 70 parts by weight or less. If the polybutylene adipate terephthalate (PBAT) is included in an excessively small amount in the resin composition, the elongation of the film produced therefrom may be reduced, and if the polybutylene adipate terephthalate is included in an excessively large amount in the resin composition, the tensile properties of the film produced therefrom, such as Young's modulus and yield tensile strength, may be reduced.

[0067]

[0068] In addition, the resin composition of the present invention comprises polylactic acid. In this specification, “polylactic acid (PLA)” refers to a lactide polymer and is used with the same meaning as “polylactide.”

[0069]

[0070] Lactide or lactide monomers may be L-lactide derived from two L-lactic acid molecules; D-lactide derived from two D-lactic acid molecules; meso-lactide derived from L-lactic acid molecules and D-lactic acid molecules; or a mixture of two or more of these. It may also be racemic lactide, which is a 50:50 mixture of L-lactide and D-lactide. Accordingly, PLA in this specification may be a lactide polymer selected from the group comprising L-lactide, D-lactide, meso-lactide, racemic lactide, and any mixture of two or more of these.

[0071]

[0072] According to one embodiment of the present invention, according to one embodiment of the invention, polylactic acid may be included in an amount of about 0.1 to about 20 parts by weight, or about 1 to about 10 parts by weight, with respect to a total of 100 parts by weight of polybutylene adipate terephthalate, polylactic acid, and thermoplastic starch. If the amount of polylactic acid is excessively small, the effect of improving the mechanical properties of PBAT may not appear, and if the amount of polylactic acid is excessively large, the hardness may increase, and a problem may occur in which the elongation decreases.

[0073]

[0074] In addition, the resin composition may include thermoplastic starch (TPS) to improve the processability of polybutylene adipate terephthalate and accelerate the biodegradation rate. The thermoplastic starch may be a starch imparted with thermoplasticity by adding a plasticizer to natural polymer starch, such as polyethylene, polystyrene, and polypropylene, so that it does not carbonize even at temperatures above a certain level and can freely change its shape.

[0075]

[0076] The above thermoplastic starch may include one or more selected from the group consisting of rice starch, wheat starch, corn starch, sweet potato starch, potato starch, tapioca starch, cassava starch, and modified starches thereof.

[0077]

[0078] In addition, the plasticizer included in the natural polymer starch may be one or more selected from the group consisting of isosorbide, glycerol, sorbitol, fructose, formamide, xylitol, corn oil, and edible oil. The plasticizer may be included in an amount of 5% to 50% by weight, 10% to 45% by weight, or 15% to 35% by weight relative to 100% by weight of the total thermoplastic starch.

[0079]

[0080] A resin composition according to one embodiment of the present invention may contain 20 to 50 parts by weight of thermoplastic starch with respect to 100 parts by weight of polybutylene adipate terephthalate, polylactic acid, and thermoplastic starch. Preferably, the thermoplastic starch may be contained in an amount of 20 parts by weight or more, 22 parts by weight or more, 23 parts by weight or more, or 25 parts by weight or more with respect to 100 parts by weight of the resin composition, while being contained in an amount of 47 parts by weight or less, 45 parts by weight or less, or 40 parts by weight or less. As the content of thermoplastic starch in the resin composition increases, the cost becomes lower, making it more economical, biodegradability is improved, and the content of bio-based carbon can be increased. However, if the above thermoplastic starch is included in an excessive amount in the resin composition, the elongation of the film produced therefrom may be reduced, and if the above thermoplastic starch is included in an excessive amount in the biodegradable composition, the biodegradation rate may be slowed down and the tensile properties of the film produced therefrom, such as Young's modulus and yield tensile strength, may be reduced.

[0081]

[0082] Meanwhile, the present invention includes a compatibilizer to improve the compatibility of the polymer component. The compatibilizer includes a polyolefin elastomer grafted with maleic anhydride.

[0083]

[0084] The above maleic anhydride-grafted polyolefin elastomer is a compound prepared by grafting maleic anhydride onto the main chain of a polyolefin elastomer. When the maleic anhydride-grafted polyolefin elastomer is used as a compatibilizer, the compatibility of the resin composition is improved, and based on this, mechanical properties such as impact strength and puncture resistance can be improved.

[0085]

[0086] In addition, the polyolefin elastomer forming the main chain of the maleic anhydride grafted polyolefin elastomer is not particularly limited, but specifically, it may include one or more selected from the group consisting of polypropylene elastomer, polyethylene elastomer, polyethylenepropylene elastomer, ethylene-propylene-diene monomer elastomer, polyethylene-1-pentene elastomer, polyethylene-1-hexene elastomer, polyethylene-1-heptene elastomer, and polyethylene-1-octene elastomer. More specifically, the maleic anhydride-grafted polyolefin elastomer may be a maleic anhydride-grafted-polypropylene elastomer (MAH-g-PP), a maleic anhydride-grafted-polyethylene elastomer (MAH-g-PE), or a maleic anhydride-grafted-ethylene-propylene-diene monomer elastomer (MAH-g-EPDM).

[0087]

[0088] The graft rate of the polyolefin elastomer grafted with maleic anhydride may be 0.1 to 2.0 weight%. Preferably, it may be 0.1 to 1.5 weight%, 0.3 to 1.0 weight%, 0.4 to 0.8 weight%, or 0.5 weight%. By controlling the graft rate of maleic anhydride within the above-described range, the tensile properties and moldability of the resin molded article made from the resin composition can be improved.

[0089]

[0090] According to one embodiment of the present invention, a polyolefin elastomer grafted with maleic anhydride may be included in an amount of 0.01 to 2.0 parts by weight with respect to a total of 100 parts by weight of polybutylene adipate terephthalate (PBAT), polylactic acid, and thermoplastic starch. For example, with respect to a total of 100 parts by weight of polybutylene adipate terephthalate, polylactic acid, and thermoplastic starch, which are resin components of the resin composition, the polyolefin elastomer grafted with maleic anhydride may be included in an amount of 0.03 parts by weight or more, 0.05 parts by weight or more, 0.07 parts by weight or more, 0.1 parts by weight or more, or 0.3 parts by weight or more, and may be included in an amount of 1.5 parts by weight, 1.3 parts by weight, 1.0 parts by weight, 0.8 parts by weight or less, or 0.5 parts by weight or less. In this way, by including a polyolefin elastomer grafted with maleic anhydride within the above range together with a maleic acid-modified polyester copolymer, it is possible to improve compatibility while simultaneously improving mechanical properties.

[0091]

[0092] More specifically, a resin composition according to one embodiment of the present invention may comprise, based on a total of 100 parts by weight of polybutylene adipate terephthalate, polylactic acid, and thermoplastic starch, 40 to 79 parts by weight of polybutylene adipate terephthalate, 0.1 to 20 parts by weight of polylactic acid, 20 to 50 parts by weight of thermoplastic starch, 0.01 to 2.0 parts by weight of a polyolefin elastomer grafted with maleic anhydride, and 0.1 to 0.5 parts by weight of a slip agent.

[0093]

[0094] Meanwhile, according to one embodiment of the present invention, the compatibilizer may further include polybutylene adipate terephthalate in which maleic acid is ester-bonded to the terminal hydroxyl group.

[0095]

[0096] Polybutylene adipate terephthalate, in which maleic acid is ester-bonded to the terminal hydroxyl group, can be prepared by esterifying the terminal hydroxyl group of polybutylene adipate terephthalate with maleic acid. That is, the carboxyl group contained in maleic acid may be an esterified product formed through an esterification reaction with the terminal hydroxyl group of polybutylene adipate terephthalate.

[0097]

[0098] Polybutylene adipate terephthalate in which maleic acid is ester-bonded to the terminal hydroxyl group can be prepared by esterifying maleic acid and polybutylene adipate terephthalate as described above. By controlling the content of maleic acid, the content of polybutylene adipate terephthalate, the reaction temperature, the reaction time, and the type and content of additives, polybutylene adipate terephthalate in which maleic acid is ester-bonded to the terminal hydroxyl group can be prepared, and the weight-average molecular weight, structure, viscosity, etc., of such polybutylene adipate terephthalate in which maleic acid is ester-bonded to the terminal hydroxyl group can be controlled.

[0099]

[0100] According to one embodiment of the present invention, for example, the polybutylene adipate terephthalate in which maleic acid is ester-bonded to the terminal hydroxyl group may have a viscosity of 500 Pa.s or more and 5,000 Pa.s or less at a temperature of 120°C to 180°C, 130°C to 170°C, 140°C to 160°C, or 150°C. For example, the viscosity may be 1,000 Pa.s or more, 1,500 Pa.s or more, 1,800 Pa.s or more, 2,000 Pa.s or more, 2,100 Pa.s or more, 2,200 Pa.s or more, and 4,800 Pa.s or less, 4,600 Pa.s or less, and 4,400 Pa.s or less.

[0101] If the viscosity of the polybutylene adipate terephthalate in which maleic acid is ester-bonded to the terminal hydroxyl groups is excessively high, the effect of improving compatibility does not appear, and mechanical properties such as tensile strength of the film prepared with the composition may be degraded. If the viscosity of the polybutylene adipate terephthalate in which maleic acid is ester-bonded to the terminal hydroxyl groups is excessively low, the thermal diffusivity of the resin composition is lowered, resulting in inferior moldability and / or processability and increased process operating costs.

[0102]

[0103] In addition, the polybutylene adipate terephthalate in which maleic acid is ester-bonded to the terminal hydroxyl group may contain maleic acid in an amount of 1.0 weight% or more and 10.0 weight% or less.

[0104] Specifically, regarding 100 wt% of polybutylene adipate terephthalate containing maleic acid ester-bonded to the terminal hydroxyl group, maleic acid may be included in an amount of 1.5 wt% or more, 2.0 wt% or more, 2.5 wt% or more, 2.7 wt% or more, 3.0 wt% or more, or 3.5 wt% or more, and may be included in an amount of 8.0 wt% or less, 7.0 wt% or less, 6.0 wt% or less, 5.5 wt% or less, or 5.0 wt% or less.

[0105]

[0106] If the polybutylene adipate terephthalate, in which maleic acid is ester-bonded to the terminal hydroxyl groups, contains an excessively small amount of maleic acid, the compatibility of the resin composition may be reduced. The compatibility of the resin composition can be evaluated by measuring the specific surface area, which is a factor regarding the degree to which the composition recovers when the strain is increased and then lowered; the smaller the non-recovery area, the better the distribution of the dispersed phase to the continuous phase contained in the composition, and thus the better the compatibility.

[0107] Furthermore, if polybutylene adipate terephthalate, in which maleic acid is ester-bonded to terminal hydroxyl groups, contains an excessive amount of maleic acid, the thermal diffusivity of the resin composition decreases, which can lead to inferior moldability and / or processability and increase process operating costs. Specifically, in a process for manufacturing a film by reactive extrusion of a resin composition, the compound discharged from the extruder passes through a cooling bath to cool and is then cut (pelletized). However, if the composition contains an excessive amount of maleic acid, the low thermal diffusivity of the resin composition slows down the cooling rate of the discharged compound, making cutting difficult. Consequently, this results in inferior moldability and / or processability, or increases process operating costs due to the need for additional cooling equipment.

[0108]

[0109] According to one embodiment, the molecular weight of the polybutylene adipate terephthalate in which maleic acid is ester-bonded to the terminal hydroxyl group may be 100,000 g / mol to 150,000 g / mol. The weight-average molecular weight may be 110,000 g / mol or more, 120,000 g / mol or more, or 130,000 g / mol or more, and 147,000 g / mol or less, 145,000 g / mol or less, 142,000 g / mol or less, or 140,000 g / mol or less. If the molecular weight of the polybutylene adipate terephthalate in which maleic acid is ester-bonded to the terminal hydroxyl group does not satisfy the above-described range, the effect of improving compatibility does not appear, and mechanical properties such as tensile strength of the film prepared with the composition may be reduced.

[0110]

[0111] Meanwhile, the maleic acid-modified polyester copolymer may include one or more of a repeating unit represented by the following chemical formula 1 and a structure represented by the following chemical formula 2:

[0112] [Chemical Formula 1]

[0113]

[0114] [Chemical Formula 2]

[0115]

[0116]

[0117] The repeating unit represented by the above chemical formula 1 is a structure in which maleic acid forms an ester bond at the end of the butylene-adipate repeating unit of polybutylene adipate terephthalate, and the repeating unit represented by the above chemical formula 2 is a structure in which maleic acid forms an ester bond at the end of the butylene-terephthalate repeating unit.

[0118] In addition, in addition to the repeating unit represented by Chemical Formula 1 and the repeating unit represented by Chemical Formula 2, the structure may be one in which two carboxyl groups of maleic acid each form an ester bond.

[0119] In addition, the number of repeating units represented by Chemical Formula 1 and the number of half-repetition units represented by Chemical Formula 2 can be appropriately adjusted according to the desired physical properties of the maleic acid-modified polyester copolymer.

[0120]

[0121] According to one embodiment of the present invention, the maleic acid modified polyester copolymer may be included in an amount of 0.1 to 10 weight% based on the total weight of the polybutylene adipate terephthalate (PBAT), polylactic acid, thermoplastic starch, and maleic acid modified polyester copolymer. For example, based on the total weight of the resin components of the resin composition, namely polybutylene adipate terephthalate, polylactic acid, thermoplastic starch, and maleic acid-modified polyester copolymer, the maleic acid-modified polyester copolymer may be included in an amount of 0.1 wt% or more, 0.3 wt% or more, 0.5 wt% or more, 0.7 wt% or more, 1 wt% or more, 1.2 wt% or more, 1.5 wt% or more, or 2.0 wt% or more, and may be included in an amount of 10.0 wt% or less, 7.0 wt% or less, 5.0 wt% or less, 4.5 wt% or less, 4.0 wt% or less, or 3.5 wt% or less. If the above maleic acid-modified polyester copolymer is included in an excessively small amount, the effect of improving compatibility does not appear, and mechanical properties such as tensile strength of the film prepared with the composition may be reduced, and if the above maleic acid-modified polyester copolymer is included in an excessive amount, the melt viscosity becomes excessively high, which may reduce moldability.

[0122]

[0123] In addition, the resin composition according to one embodiment of the invention may further include other additives. The additives may be any general additives used in the molding of resin compositions in the technical field to which the present invention belongs, that is, in the field of thermoplastic polymers, without any particular limitation.

[0124] The additive may include a heat stabilizer, a UV stabilizer, a slip agent, or a lubricant. The additive may be included in an amount of 0.1 to 5 parts by weight per 100 parts by weight of the total of the polybutylene adipate terephthalate, polylactic acid, thermoplastic starch, and compatibilizer.

[0125]

[0126] According to one embodiment of the present invention, the resin composition of the present invention may be composed of 40 to 79 parts by weight of polybutylene adipate terephthalate, 0.1 to 20 parts by weight of polylactic acid, 20 to 50 parts by weight of thermoplastic starch, 0.01 to 1 part by weight of a polyolefin elastomer grafted with maleic anhydride, and 0.1 to 0.5 parts by weight of a slip agent, based on a total of 100 parts by weight of polybutylene adipate terephthalate, polylactic acid, and thermoplastic starch.

[0127]

[0128] In addition, the present invention provides a resin molded article comprising the aforementioned resin composition. Furthermore, the resin molded article may be a biodegradable mulching film or a food packaging film, and more specifically, may be used for purposes such as an agricultural mulching film or a packaging material.

[0129]

[0130] According to one embodiment of the present invention, the resin molded article has a tensile strength value of approximately 200 kgf / cm² as measured according to ISO 527 standards. 2 Up to about 500 kgf / cm² 2 , or about 220 kgf / cm² 2 Up to about 400 kgf / cm² 2 , or about 230 kgf / cm² 2 Up to about 350 kgf / cm² 2 It may be. More specifically, the MD direction tensile strength is 200 kgf / cm² 2 Up to 300 kgf / cm² 2 , 210 kgf / cm 2 Up to 280 kgf / cm² 2 , 230 kgf / cm 2 Up to 270 kgf / cm² 2 It may be, and the tensile strength in the TD direction is 250 kgf / cm² 2 Up to 350 kgf / cm² 2 , or 260 kgf / cm² 2 Up to 330 kgf / cm² 2 It could be.

[0131]

[0132] In addition, the resin molded article may have an elongation value of approximately 350% to approximately 1000%, or approximately 350% to approximately 800%, or approximately 350% to 700% as measured according to ISO 527 standards, and may have a very excellent elongation value. More specifically, the elongation in the MD direction may be 350% to 600%, or 380% to 550%, and the elongation in the TD direction may be 550% to 700%, or 600% to 700%.

[0133]

[0134] According to one embodiment of the present invention, the Dart impact measured according to ASTM D1709 standards may be 400 g or more and 2.5 J or more. More specifically, based on Mass, it may be 405 g or more, 410 g or more, 415 g or more, 420 g or more, 425 g or more, or 430 g or more, and 500 g or less. In addition, based on Energy, it may be 2.6 J or more, 2.7 J or more, or 2.8 J or more, and 10.0 J or less.

[0135]

[0136] According to one embodiment of the present invention, the Puncture resistance value measured according to ASTM D5748 standards may be 15.0 N or more, 70.0% or more, and 0.70 J or more. More specifically, the Force may be 15.1 N or more, 15.2 N or more, 15.3 N or more, 15.4 N or more, or 15.5 N or more; the Distance may be 71.0% or more, 72.0% or more, 73.0% or more, or 74.0% or more; and the Energy may be 0.71 J or more, 0.72 J or more, 0.73 J or more, or 0.74 J or more.

[0137]

[0138] As described above, the resin molded article according to one example of the present invention is suitable for use in applications such as biodegradable mulching films or food packaging films due to its mechanical properties.

[0139]

[0140] As described above, the resin composition of the present invention can achieve excellent mechanical properties while maintaining the biodegradability of polybutylene adipate terephthalate.

[0141]

[0142] Preferred embodiments are presented below to aid in understanding the invention. However, the following embodiments are merely illustrative of the invention and do not limit the invention to these embodiments.

[0143]

[0144] <Example>

[0145] Preparation Example: Preparation of polybutylene adipate terephthalate (PBAT-MA(5.0)) in which maleic acid is ester-bonded to the terminal hydroxyl groups

[0146] 100 g of polybutylene adipate terephthalate (PBAT, Solpol 1000N, SOLTECH) and 5 g of maleic anhydride were added to an internal mixer and reacted while mixing for 10 minutes at a temperature of 160 ℃ and 50 rpm to prepare polybutylene adipate terephthalate in which maleic acid is ester-bonded to the terminal hydroxyl groups (weight-average molecular weight: 135,000, viscosity measured at 150 ℃ and 0.1 rad / s: 2269.52 Pa.s).

[0147]

[0148] The compounds used in the following examples and comparative examples are as follows.

[0149] Polybutylene adipate terephthalate: LG CHEM SF1000 (Density: 1.20-1.25, MFI (ASTM D1238, 190 ℃ 2.16 kg): 2.5-4.5 g / 10 min)

[0150] Polylactic acid: Total Corbion LX-175™ (Density: 1.24 g / cm³, MFI (ISO 1133-11, 190 ℃ 2.16 kg): 3.00 g / 10 min)

[0151] Thermoplastic Starch: EcoCyco's HSM TM (Density: 1.5 g / cm³ 3 )

[0152] Compatibilizer A: Maleic anhydride grafted polyolefin elastomer (POE-g-MA, FUSABOND N493™ from DOW, Density: 0.87 g / cm³, Melting point: 50 °C, Freezing point: 28 °C, Melt index (190 °C 2.16 Kg): 1.6 g / 10 min, Graft rate: 0.5 wt%)

[0153] Commercial Agent B: PBAT-MA of the Preparation Example

[0154] Slip agent: Pentaerythritol tetrastearate (Loxiol P861 / 3.5, SpecialChem)

[0155]

[0156] Examples and Comparative Examples

[0157] A resin composition was prepared by mixing according to the compositions listed in Tables 1 and 2 below.

[0158] Specifically, the polybutylene adipate terephthalate (PBAT), polylactic acid (PLA), thermoplastic starch (TPS), compatibilizer A, compatibilizer B, and slip agent were fed into a twin-screw extruder (die diameter = 32 mm) in the compositions listed in Table 1 and Table below. Subsequently, the resin composition was produced in the form of pellets by extruding under conditions of Barrel Temperature 190 ℃, Feed Rate 50 kg / hr, and 300 rpm.

[0159]

[0160] PBAT (parts by weight) PLA (parts by weight) TPS (parts by weight) Compatibilizer A (parts by weight) Compatibilizer B (weight %) a ) Slip agent (parts by weight) Comparative Example 18 19 10--0.2 Comparative Example 27 28 20--0.2 Comparative Example 36 37 30--0.2 Comparative Example 45 46 40--0.2 Example 1-16 37 30 0.1-0.2 Example 1-26 37 30 0.5-0.2 Example 1-36 37 30 1.0-0.2 Example 1-47 0.5 4.5 25 0.5-0.2 Example 1-56 96 25 0.5-0.2 Example 1-66 7.5 7.5 25 0.5-0.2

[0161] PBAT (parts by weight) PLA (parts by weight) TPS (parts by weight) Compatibilizer A (parts by weight) Compatibilizer B (weight %) a ) Slip agent (parts by weight) Comparative Example 556440--0.2 Example 2-1564400.1-0.2 Example 2-2534400.13.00.2 Example 2-3534400.53.00.2

[0162] a) Weight % is based on the total weight of PBAT, PLA, TPS, and compatibilizer B.

[0163] Film manufacturing

[0164] A blown film was prepared by molding the pellet-shaped resin composition prepared in the above examples and comparative examples using a single screw extruder (Single Screw Extruder, Blown Film M / C, 19 pi, L / D=25) at an extrusion temperature of 160 ℃ to a thickness of 0.025 mm.

[0165]

[0166] Measurement of physical properties

[0167] - Tensile strength and elongation

[0168] For the film prepared above, the tensile strength and elongation values ​​in the MD and TD directions of the film were measured using a universal testing machine according to ISO 527 standards. At this time, the specimens were prepared in the shape of a bar (width * length = 10 mm * 150 mm).

[0169]

[0170] - Dart impact

[0171] For the film prepared above, the film impact strength value was measured according to ASTM D1709 standards using the Falling dart method.

[0172]

[0173] - Puncture resistance

[0174] For the film prepared above, the puncture resistance value was measured using a universal testing machine according to ASTM D5748 standards.

[0175]

[0176] - Practical test

[0177] For the film manufactured above, it was fixed to a circular clamp with a diameter of 127 mm, and weights of 60 / 90 g were placed to measure the maximum weight the film could withstand.

[0178]

[0179] The above measurement results are shown in Tables 3 to 5 below.

[0180]

[0181] MD direction TD direction tensile strength (kgf / cm²) 2 Elongation (%) Tensile Strength (kgf / cm²) 2 ) Elongation (%) Comparative Example 1 2 18 39 225 26 28 Comparative Example 2 2 36 37 8 25 6 6 30 Comparative Example 3 2 31 38 0 219 5 57 Comparative Example 4 2 18 35 8 19 0 48 1 Example 1-1 2 39 40 8 25 8 6 17 Example 1-2 2 46 41 12 69 6 32 Example 1-3 2 41 42 72 71 6 37 Example 1-4 2 60 51 13 16 6 6 3 Example 1-5 2 43 40 52 8 7 6 50 Example 1-6 2 40 38 6 27 9 6 33

[0182] Dart impact Puncture resistance Mass (g) Energy (J) Force (N) Distance (%) Energy (J) Comparative Example 1 31 2.0 1 3.6 6 5.9 0.55 Comparative Example 2 335 2.2 1 3.2 6 6.8 0.57 Comparative Example 3 39 2.5 1 4.4 7 2.5 0.69 Comparative Example 4 40 2.6 1 4.6 7 2.9 0.71 Example 1-1 437 2.8 1 5.7 7 3.7 0.74 Example 1-2 479 3.1 1 7.6 78.2 0.90 Example 1-3 458 3.0 1 7.0 77.7 0.86 Example 1-4 418 2.7 1 5.9 74.7 0.79 Example 1-54322.817.076.60.84 Example 1-64392.818.771.20.85

[0183] Dart impact Puncture resistance Practical test Mass(g) Energy(J) Force(N) Distance(%) Energy(J) Weight(kg) Comparative Example 5 4 2 6 2.8 1 4.3 9 2.4 0.8 5 1 0.96 Example 2-1 4 5 7 3.0 1 5.2 9 4.4 0.9 0 1 1.20 Example 2-2 4 7 8 3.1 1 6.9 1 0 2.3 1.1 3 1 2.82 Example 2-3 4 9 1 3.2 1 7.7 1 0 3.4 1.1 6 1 3.8 4

[0184] As can be seen in Table 3 above, it was confirmed that the resin composition containing a maleic anhydride grafted polyolefin elastomer according to the present invention had improved tensile strength and elongation compared to the resin composition of a comparative example that does not contain a compatibilizer.

[0185] In addition, as can be seen in Table 4, it was confirmed that the impact strength of the resin composition according to the present invention increased. Furthermore, as can be seen in Table 5, it was confirmed that the resin composition further comprising polybutylene adipate terephthalate in which maleic acid is ester-bonded to the terminal hydroxyl groups showed improved impact strength, while simultaneously exhibiting excellent puncture resistance and practical test results.

Claims

1. Polybutylene adipate terephthalate (PBAT); Polylactic acid (PLA); Thermoplastic starch (TPS); and Includes commercial agents, The above-mentioned compatibilizer comprises a maleic anhydride-grafted polyolefin elastomer, Resin composition.

2. In Paragraph 1, A composition comprising 0.1 to 20 parts by weight of polylactic acid based on 100 parts by weight of the above polybutylene adipate terephthalate, polylactic acid, and thermoplastic starch, Resin composition.

3. In Paragraph 1, A composition comprising 20 to 50 parts by weight of thermoplastic starch based on a total of 100 parts by weight of the above polybutylene adipate terephthalate, polylactic acid, and thermoplastic starch, Resin composition.

4. In Paragraph 1, The above polyolefin elastomer comprises one or more selected from the group consisting of polypropylene elastomer, polyethylene elastomer, polyethylenepropylene elastomer, ethylene-propylene-diene monomer elastomer, polyethylene-1-pentene elastomer, polyethylene-1-hexene elastomer, polyethylene-1-heptene elastomer, and polyethylene-1-octene elastomer. Resin composition.

5. In Paragraph 1, The graft rate of the maleic anhydride-grafted polyolefin elastomer is 0.1 to 2.0 weight%, Resin composition.

6. In Paragraph 1, A polyolefin elastomer grafted with maleic anhydride comprising 0.01 to 1 weight part, based on a total of 100 weight parts of the above polybutylene adipate terephthalate, polylactic acid, and thermoplastic starch. Resin composition.

7. In Paragraph 1, Based on a total of 100 parts by weight of polybutylene adipate terephthalate, polylactic acid, and thermoplastic starch, the composition comprises 40 to 79 parts by weight of polybutylene adipate terephthalate, 0.1 to 20 parts by weight of polylactic acid, 20 to 50 parts by weight of thermoplastic starch, 0.01 to 1 part by weight of maleic anhydride-grafted polyolefin elastomer, and 0.1 to 0.5 parts by weight of a slip agent, Resin composition.

8. In Paragraph 1, The above-mentioned commercialization agent further comprises polybutylene adipate terephthalate in which maleic acid is ester-bonded to the terminal hydroxyl groups, Resin composition.

9. In Paragraph 8, The viscosity of the polybutylene adipate terephthalate in which maleic acid is ester-bonded to the hydroxyl groups at the terminals is 500 Pa.s to 5,000 Pa.s, Resin composition.

10. In Paragraph 8, Polybutylene adipate terephthalate in which maleic acid is ester-bonded to the terminal hydroxyl groups comprises 1.0% to 10.0% by weight of maleic acid. Resin composition.

11. In Paragraph 8, Polybutylene adipate terephthalate having maleic acid ester-bonded to the terminal hydroxyl groups has a weight-average molecular weight of 100,000 g / mol to 150,000 g / mol, Resin composition.

12. In Paragraph 8, Based on the total weight of the above polybutylene adipate terephthalate, polylactic acid, thermoplastic starch, and polybutylene adipate terephthalate in which maleic acid is ester-bonded to a terminal hydroxyl group, the composition comprises 0.1 to 10 weight% of polybutylene adipate terephthalate in which maleic acid is ester-bonded to a terminal hydroxyl group. Resin composition.

13. A resin molded article comprising a resin composition according to any one of claims 1 to 12.

14. In Paragraph 13, Tensile strength value measured according to ISO 527 standard is 200 kgf / cm 2 Up to 500 kgf / cm² 2 person, Resin molded product.

15. In Paragraph 13, elongation value measured according to ISO 527 standards of 350% to 1000%, Resin molded product.

16. In Paragraph 13, With a Dart impact of 400 g or more and 2.5 J or more as measured according to ASTM D1709 standards, Resin molded product.

17. In Paragraph 13, Puncture resistance values ​​measured according to ASTM D5748 standards of 15.0 N or more, 70.0% or more, and 0.70 J or more, Resin molded product.

18. A resin molded article, which is a biodegradable mulching film or a food packaging film, according to paragraph 13.

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