Polyester polymer, method for producing polyester polymer, and molded article

Abstract

This invention relates to a polyester polymer having a high bio-content and molecular weight, as well as excellent optical properties, a method for producing the polyester polymer, and a molded article.

Description

Technical Field

[0001] Mutual citation with related applications This application claims the benefit of priority based on Korean Patent Application No. 10-2023-0119289 filed on September 7, 2023, and Korean Patent Application No. 10-2024-0097522 filed on July 23, 2024, and all the contents disclosed in the documents of the Korean patent applications are included as part of this specification.

[0002] The present invention relates to a polyester polymer, a method for producing a polyester polymer, and a molded article.

Background Art

[0003] Unlike existing petroleum-based resins such as polystyrene resin, polyvinyl chloride resin, and polyethylene, biodegradable polyester polymers have effects such as preventing depletion of petroleum resources and suppressing carbon dioxide emissions, and thus can reduce environmental pollution, which is a disadvantage of petroleum-based plastic products. Therefore, as the environmental pollution problem caused by waste plastics and the like has emerged as a social problem, efforts are being made to expand the scope of application to product fields where general plastics (petroleum-based resins) such as food packaging materials and containers, and electronic product cases are used.

[0004] However, existing polyester polymers have problems such as high yellowness of the polymer obtained after polymerization or difficulty in obtaining a high molecular weight polymer. In order to solve such problems, color improvement additives such as toners or chain extenders can be used, but there is a risk of burden from the perspective of raw material costs.

[0005] Also, recently, concerns about depletion of petroleum resources, increase in carbon dioxide emissions, and global warming and climate change due to accumulation have been increasing, and there is a demand for providing polymers using raw materials obtained from biomass resources such as plants.

[0006] Conventional polyester polymers are manufactured using petroleum-based monomers and are not polymerized using bio-based monomers, resulting in low bio-content and the inability to achieve carbon neutrality. Furthermore, even when bio-based monomers are used in the synthesis of polyester polymers, conventional biosynthesis using microorganisms requires large amounts of solvents in the separation and purification processes, making it neither environmentally friendly nor economically viable.

[0007] Therefore, there is a need for research into environmentally friendly polyester polymers that possess excellent physical properties and high molecular weight without the use of additional additives, as well as high bio-content. [Overview of the project] [Problems that the invention aims to solve]

[0008] The present invention provides a polyester polymer having a high bio-content and high molecular weight, as well as excellent optical properties, without the use of chain extenders, a method for producing the polyester polymer, and a molded article. [Means for solving the problem]

[0009] According to one embodiment of the present invention, a polyester polymer is provided which contains repeating units represented by the following chemical formula 1, has a biomass content of 20% or more as measured by ASTM D6866-22, and decomposes by 20% by weight or more relative to the weight of the initial polymer when exposed to the external environment at room temperature for 90 days or more. [ka]

[0010] In the aforementioned chemical formula 1, L1 is an ethylene group, and L2 is an alkylene group having 1 to 10 carbon atoms.

[0011] Another embodiment of the present invention provides a method for producing a polyester polymer, comprising the steps of: adding ethylene glycol and a dicarboxylate compound and reacting them at a temperature of 50°C to 200°C and a pressure of 10 torr to 760 torr to produce an oligomer; and reacting the oligomer at a temperature of 50°C to 200°C and a pressure of 1 torr to produce a polyester polymer.

[0012] According to another embodiment of the present invention, a molded article is provided which is molded from a resin composition containing the polyester polymer.

[0013] The following describes in more detail polyester polymers, methods for producing polyester polymers, and molded articles according to specific embodiments of the present invention.

[0014] Throughout this specification, unless otherwise specified, “contains” or “includes” means to include a particular component (or constituent) without any particular limitation, and should not be construed as excluding the addition of other components (or constituents).

[0015] In this invention, terms such as "first," "second," etc., are used to describe various components, and are used solely for the purpose of distinguishing one component from other components.

[0016] Furthermore, unless explicitly stated or otherwise specifically mentioned, the steps constituting a manufacturing method described herein are not construed as being limited to the order in which one step and another steps constituting a single manufacturing method are described in the specification. Therefore, the order of the steps constituting a manufacturing method can be changed to the extent that is easily understood by those skilled in the art, and in this case, the resulting changes are within the scope of the present invention.

[0017] Unless otherwise specified herein, the number average molecular weight or the weight average molecular weight can be measured using gel permeation chromatography (GPC). Specifically, after dissolving the prepolymer or copolymer in chloroform to a concentration of 1 mg / ml, 100 μl is injected into GPC, and GPC analysis is performed at 40°C. At this time, chloroform is used as the mobile phase of GPC and flows in at a flow rate of 1.0 mL / min. Two Agilent Mixed-B columns are connected in series and used, and an RI Detector is used as the detector. The Mw value is derived using a calibration curve formed with polystyrene standard specimens. The weight average molecular weights of the polystyrene standard specimens used are 12 types including 160 g / mol, 580 g / mol, 1180 g / mol, 4,880 g / mol, 9,310 g / mol, 22,790 g / mol, 75,050 g / mol, 217,900 g / mol, 479,200 g / mol, 1,069,000 g / mol, 3,022,000 g / mol, and 6,545,000 g / mol.

[0018] In this specification, the copolymer is used in the sense of including any of random copolymers, block copolymers, graft copolymers, etc.

[0019] In this specification, the term "block" means a polymer in which two or more repeating units are linked, and the term "block copolymer" means a copolymer in which two or more types of blocks are directly bonded or linked through a linking group, respectively, one or more at a time.

[0020] In this specification,

Chem.

Chem.

[0021] According to one embodiment of the present invention, there is provided a polyester polymer containing a repeating unit represented by the following Chemical Formula 1, having a biomass content of 20% or more measured by ASTM D6866-22, and when exposed to the external environment at room temperature for 90 days or more, 20% by weight or more of the original polymer weight is decomposed. [Chemical Formula]

[0022] In the above Chemical Formula 1, L1 is an ethylene group, and L2 is an alkylene group having 1 to 10 carbon atoms.

[0023] The polyester polymer of the above embodiment may be a polyester polymer produced by the production method of the polyester polymer of other embodiments described later.

[0024] By producing the polyester polymer of the above embodiment by the production method of the polyester polymer of other embodiments described above, it is possible to provide a polyester polymer having a high bio-content and high molecular weight and excellent optical properties.

[0025] In the above Chemical Formula 1, L2 may be a functional group derived from a dicarboxylic acid compound.

[0026] L2 may be an alkylene group having 1 to 10 carbon atoms, an alkylene group having 1 to 5 carbon atoms, or an alkylene group having 1 to 3 carbon atoms, and for example, may be an ethylene group.

[0027] For example, the polyester polymer of the above embodiment may be polyethylene succinate.

[0028] The polyester polymer may contain, with respect to the total repeating units, the repeating units represented by the chemical formula 1 in amounts of 90 mol% or more, 95 mol% or more, 99 mol% or more, 99.9 mol% or more, or 90 mol% or more and 100 mol% or less, 95 mol% or more and 100 mol% or less, 99 mol% or more and 100 mol% or less, or 99.9 mol% or more and 100 mol% or less.

[0029] For example, the polyester polymer may consist of repeating units represented by the chemical formula 1. In other words, the polyester polymer can contain only ethylene glycol and succinic acid as monomers, and does not contain any other monomers, and therefore can contain only repeating units derived from ethylene glycol and succinic acid.

[0030] The polyester polymer may have a number-average molecular weight (Mn) of 1,000 g / mol or more and 200,000 g / mol or less, as measured by gel permeation chromatography (GPC).

[0031] Specifically, the polyester polymer may have a number-average molecular weight (Mn) measured using gel permeation chromatography (GPC) of 1,000 g / mol or more, 1,500 g / mol or more, 2,000 g / mol or more, 2,500 g / mol or more, 200,000 g / mol or less, 100,000 g / mol or less, 80,000 g / mol or less, or 60,000 g / mol or less, and may also have a number-average molecular weight (Mn) of 1,000 g / mol or more and 200,000 g / mol or less, 1,500 g / mol or more and 200,000 g / mol or less, 2,000 g / mol or more and 200,000 g / mol or less, 2,500 g / mol or more and 200,000 g / mol or less, 1,000 g / mol or more and 100,000 g / mol or less, or 1,500 g / mol or more and 200,000 g / mol or less. It may also be 0 g / mol or more and 100,000 g / mol or less, 2,000 g / mol or more and 100,000 g / mol or less, 2,500 g / mol or more and 100,000 g / mol or less, 1,000 g / mol or more and 80,000 g / mol or less, 1,500 g / mol or more and 80,000 g / mol or less, 2,000 g / mol or more and 80,000 g / mol or less, 2,500 g / mol or more and 80,000 g / mol or less, 1,000 g / mol or more and 60,000 g / mol or less, 1,500 g / mol or more and 60,000 g / mol or less, 2,000 g / mol or more and 60,000 g / mol or less, or 2,500 g / mol or more and 60,000 g / mol or less.

[0032] The polyester polymer of the above embodiment, when produced by the manufacturing method described above, can have a high molecular weight and excellent optical properties even without a chain extender.

[0033] The polyester polymer may have a weight-average molecular weight (Mw) of 5,000 g / mol or more and 600,000 g / mol or less, as measured by gel permeation chromatography (GPC).

[0034] Specifically, the polyester polymer may have a weight-average molecular weight (Mw) measured using gel permeation chromatography (GPC) of 5,000 g / mol or more, 5,500 g / mol or more, 6,000 g / mol or more, 6,500 g / mol or more, 600,000 g / mol or less, 300,000 g / mol or less, 250,000 g / mol or less, or 200,000 g / mol or less, and may also have a weight-average molecular weight (Mw) of 5,000 g / mol or more and 600,000 g / mol or less, 5,500 g / mol or more and 600,000 g / mol or less, 6,000 g / mol or more and 600,000 g / mol or less, 6,500 g / mol or more and 600,000 g / mol or less, 5,000 g / mol or more and 300,000 g / mol or less, or 5,500 g / It may also be 300,000 g / mol or more, 6,000 g / mol or more and 300,000 g / mol or less, 6,500 g / mol or more and 300,000 g / mol or less, 5,000 g / mol or more and 250,000 g / mol or less, 5,500 g / mol or more and 250,000 g / mol or less, 6,000 g / mol or more and 250,000 g / mol or less, 6,500 g / mol or more and 250,000 g / mol or less, 5,000 g / mol or more and 200,000 g / mol or less, 5,500 g / mol or more and 200,000 g / mol or less, 6,000 g / mol or more and 200,000 g / mol or less, or 6,500 g / mol or more and 200,000 g / mol or less.

[0035] The polyester polymer of the above embodiment, when produced by the manufacturing method described later, can have a high molecular weight and excellent optical properties even without a chain extender.

[0036] On the other hand, the polyester polymer may have a biomass content of 20% or more, as measured by ASTM D6866-22. Specifically, the polyester polymer may have a biomass content measured according to ASTM D6866-22 of 20% or more, 50% or more, 90% or more, 95% or more, 98% or more, 99% or more, 100% or less, 99.9% or less, 20% or more and 100% or less, 50% or more and 100% or less, 90% or more and 100% or less, 95% or more and 100% or less, 98% or more and 100% or less, 99% or more and 100% or less, 20% or more and 99.9% or less, 50% or more and 99.9% or less, 90% or more and 99.9% or less, 95% or more and 99.9% or less, 98% or more and 99.9% or less, or 99% or more and 99.9% or less.

[0037] The aforementioned polyester polymer can be produced from a monomer derived from bio, as well as by the polyester polymer production method of other embodiments described later, thereby producing a polyester polymer with a high bio-content.

[0038] For example, if the polyester polymer is derived from a single monomer of bio origin, the polyester polymer may have a biomass content of 20% to 100% or 20% to 99.9% as measured by ASTM D6866-22.

[0039] Alternatively, if the polyester polymer is derived from two types of monomers of bio origin, the polyester polymer may have a biomass content of 90% or more, 95% or more, 98% or more, 99% or more, 100% or less, 99.9% or less, 90% or more and 100% or less, 95% or more and 100% or less, 98% or more and 100% or less, 99% or more and 100% or less, 90% or more and 99.9% or less, 95% or more and 99.9% or less, 98% or more and 99.9% or less, or 99% or more and 99.9% or less.

[0040] The biomass content is obtained by graphitizing the polyester polymer and then adding radioactive isotopes. 14 The C content may be calculated according to ASTM D6866-22.

[0041] Since the aforementioned polyester polymer has a biomass content of 90% or more as measured by ASTM D6866-22, it does not contain petroleum-based monomers, thereby achieving carbon neutrality.

[0042] Specifically, a monomer derived from biomass can be defined as a monomer obtained from biomass resources such as plants.

[0043] The polyester polymer in the above embodiment may be a biodegradable polyester polymer that exhibits biodegradability.

[0044] In this specification, a biodegradable resin or biodegradable (co)polymer means a resin or (co)polymer that undergoes natural decomposition when exposed to the outside environment, and more specifically, a resin or (co)polymer that undergoes decomposition of 20% by weight or more relative to the original weight of the resin or (co)polymer when exposed to the outside environment for 90 days or more at room temperature (10°C to 30°C).

[0045] In other words, the polyester polymer of the above embodiment can decompose by 20% by weight or more relative to the original polymer weight when exposed to the external environment at room temperature for 90 days or more. The method for measuring the degree of biodegradation is not significantly limited, but may be measured, for example, by ISO 14855-1.

[0046] Another embodiment of the present invention provides a method for producing a polyester polymer, comprising the steps of: adding ethylene glycol and a dicarboxylate compound and reacting them at a temperature of 50°C to 200°C and a pressure of 10 torr to 760 torr to produce an oligomer; and reacting the oligomer at a temperature of 50°C to 200°C and a pressure of 1 torr to produce a polyester polymer.

[0047] The inventors of the present invention have discovered that when a polyester polymer is produced by the method for producing a polyester polymer of the above embodiment, a polyester polymer having a high bio-content and high molecular weight, as well as excellent optical properties, can be produced without using a chain extender, and have thus completed the present invention.

[0048] In the method for producing the polyester polymer according to the above embodiment, the ethylene glycol and dicarboxylate compound may be monomers derived from bio.

[0049] The aforementioned monomer derived from bio can mean a monomer obtained from biomass resources such as plants.

[0050] Specifically, this method for producing polyester polymers allows for the use of bio-based monomers and precise adjustment of the equivalent ratio between monomers. Therefore, it is possible to produce polyester polymers with high bio-content and high molecular weight, as well as excellent optical properties, without the need for chain extenders.

[0051] Specifically, the method for producing a polyester polymer according to the above embodiment may include the steps of: adding ethylene glycol and a dicarboxylate compound and reacting them at a temperature of 50°C to 200°C and a pressure of 10 torr to 760 torr to produce an oligomer; and reacting the oligomer at a temperature of 50°C to 200°C and a pressure of 1 torr to produce a polyester polymer.

[0052] In the above embodiment, the method for producing the polyester polymer involves carrying out both the oligomer production step and the polymerization step at 200°C or below. This allows for control of side reactions between monomers and prevents yellowing, and also enables fine adjustment of the monomer equivalent ratio using bio-based monomers. As a result, a polyester polymer with high bio-content, high molecular weight, and excellent optical properties can be produced without the use of chain extenders.

[0053] The step of producing the oligomer may be carried out at temperatures of 50°C to 200°C, 70°C to 200°C, or 90°C to 200°C.

[0054] Furthermore, the step of producing the oligomer may be carried out at pressures of 10 torr to 760 torr, 30 torr to 760 torr, 50 torr to 760 torr, 50 torr to 700 torr, 50 torr to 500 torr, or 50 torr to 400 torr.

[0055] Furthermore, the step of producing the oligomer may be carried out for a period of time of 1 hour to 30 hours, 1 hour to 20 hours, 1 hour to 10 hours, 2 hours to 10 hours, 2 hours to 8 hours, or 2 hours to 6 hours.

[0056] In other words, the step of adding the ethylene glycol and dicarboxylate compound and reacting them at a temperature of 50°C to 200°C and a pressure of 10 torr to 760 torr to produce an oligomer; may include the step of adding the ethylene glycol and dicarboxylate compound and reacting them at a temperature of 90°C to 200°C and a pressure of 50 torr to 700 torr for 1 hour to 30 hours to produce an oligomer.

[0057] By performing the oligomer production step under the aforementioned conditions, side reactions between monomers can be controlled to prevent yellowing, and the equivalent ratio between monomers can be finely adjusted using bio-based monomers. This makes it possible to produce polyester polymers with high bio-content, high molecular weight, and excellent optical properties without using chain extenders.

[0058] Furthermore, the step of reacting the oligomer at a temperature of 50°C to 200°C and a pressure of 1 torr or less to produce a polyester polymer may be carried out at temperatures of 50°C to 200°C, 70°C to 200°C, or 90°C to 200°C. Furthermore, the step of reacting the oligomer at a temperature of 50°C to 200°C and a pressure of 1 torr or less to produce a polyester polymer may be carried out at pressures of 1 torr or less, 0.1 torr to 1 torr, 0.1 torr to 0.5 torr, or 0.1 torr to 0.2 torr.

[0059] Furthermore, the step of reacting the oligomer at a temperature of 50°C to 200°C and a pressure of 1 torr or less to produce a polyester polymer may be carried out for a period of time of 1 hour to 30 hours, 1 hour to 20 hours, 10 hours to 30 hours, 10 hours to 20 hours, 12 hours to 20 hours, 15 hours to 20 hours, or 15 hours to 18 hours.

[0060] In other words, the step of reacting the oligomer at a temperature of 50°C to 200°C and a pressure of 1 torr or less to produce a polyester polymer; may include the step of reacting the oligomer at a temperature of 50°C to 200°C and a pressure of 1 torr or less for 10 hours to 30 hours to produce a polyester polymer;

[0061] By performing the step of reacting the oligomer at a temperature of 50°C to 200°C and a pressure of 1 torr or less to produce a polyester polymer, it is possible to control side reactions between monomers and prevent yellowing, and to finely adjust the equivalent ratio between monomers using bio-based monomers. This makes it possible to produce a polyester polymer with a high bio-content and high molecular weight, as well as excellent optical properties, without using chain extenders.

[0062] In particular, if the step of reacting the oligomer at a temperature of 50°C to 200°C and a pressure of 1 torr or less to produce a polyester polymer is carried out at a temperature exceeding 200°C, side reactions may occur, potentially leading to a browning phenomenon of the polyester polymer and a technical problem of excessive yellowness.

[0063] The polyester polymer produced by the method for producing a polyester polymer according to the above embodiment may be a biodegradable polyester polymer that exhibits biodegradability.

[0064] In this specification, a biodegradable resin or biodegradable (co)polymer means a resin or (co)polymer that undergoes spontaneous decomposition when exposed to the outside environment, and more specifically, a resin or (co)polymer that undergoes decomposition of 20% by weight or more relative to the original weight of the resin or (co)polymer when exposed to the outside environment for 90 days or more at room temperature (10°C to 30°C).

[0065] In other words, the polyester polymer produced by the method for producing a polyester polymer according to the above embodiment can decompose by 20% by weight or more relative to the weight of the original resin or (co)polymer when exposed to the external environment at room temperature for 90 days or more. The method for measuring the degree of biodegradation is not greatly limited, but may be measured, for example, by ISO 14855-1.

[0066] On the other hand, in the method for producing the polyester polymer according to the above embodiment, the chain extender may be included in an amount of less than 0.0001 parts by weight per 100 parts by weight of the total of the ethylene glycol and the dicarboxylate compound.

[0067] Specifically, in the method for producing the polyester polymer according to the first embodiment, the chain extender may be included in an amount of less than 0.0001 parts by weight, less than 0.000001 parts by weight, less than 0.00001 parts by weight, or 0 parts by weight, relative to 100 parts by weight of the total of the ethylene glycol and the dicarboxylate compound.

[0068] In other words, the method for producing the polyester polymer according to the above embodiment does not need to include a chain extender.

[0069] The method for producing the polyester polymer according to the above embodiment includes the steps of: adding ethylene glycol and a dicarboxylate compound as described above, reacting them at a temperature of 50°C to 200°C and a pressure of 10 torr to 760 torr to produce an oligomer; and reacting the oligomer at a temperature of 50°C to 200°C and a pressure of 1 torr to produce a polyester polymer. Since bio-based monomers can be used and the equivalent ratio between monomers can be finely adjusted, a polyester polymer with a high bio-content and high molecular weight, as well as excellent optical properties, can be produced without the use of chain extenders.

[0070] The polyester polymer may have a number-average molecular weight (Mn) of 1,000 g / mol or more and 200,000 g / mol or less, as measured by gel permeation chromatography (GPC).

[0071] Specifically, the polyester polymer may have a number-average molecular weight (Mn) measured using gel permeation chromatography (GPC) of 1,000 g / mol or more, 1,500 g / mol or more, 2,000 g / mol or more, 2,500 g / mol or more, 200,000 g / mol or less, 100,000 g / mol or less, 80,000 g / mol or less, or 60,000 g / mol or less, and may also have a number-average molecular weight (Mn) of 1,000 g / mol or more and 200,000 g / mol or less, 1,500 g / mol or more and 200,000 g / mol or less, 2,000 g / mol or more and 200,000 g / mol or less, 2,500 g / mol or more and 200,000 g / mol or less, 1,000 g / mol or more and 100,000 g / mol or less, or 1,500 g / mol or more and 200,000 g / mol or less. It may also be 0 g / mol or more and 100,000 g / mol or less, 2,000 g / mol or more and 100,000 g / mol or less, 2,500 g / mol or more and 100,000 g / mol or less, 1,000 g / mol or more and 80,000 g / mol or less, 1,500 g / mol or more and 80,000 g / mol or less, 2,000 g / mol or more and 80,000 g / mol or less, 2,500 g / mol or more and 80,000 g / mol or less, 1,000 g / mol or more and 60,000 g / mol or less, 1,500 g / mol or more and 60,000 g / mol or less, 2,000 g / mol or more and 60,000 g / mol or less, or 2,500 g / mol or more and 60,000 g / mol or less.

[0072] The method for producing the polyester polymer according to the above embodiment includes the steps of: adding ethylene glycol and a dicarboxylate compound as described above, reacting them at a temperature of 50°C to 200°C and a pressure of 10 torr to 760 torr to produce an oligomer; and reacting the oligomer at a temperature of 50°C to 200°C and a pressure of 1 torr to produce a polyester polymer. Since bio-based monomers can be used and the equivalent ratio between monomers can be finely adjusted, a polyester polymer with high molecular weight and excellent optical properties can be produced without the use of chain extenders.

[0073] The polyester polymer may have a weight-average molecular weight (Mw) of 5,000 g / mol or more and 600,000 g / mol or less, as measured by gel permeation chromatography (GPC).

[0074] Specifically, the polyester polymer may have a weight-average molecular weight (Mw) measured using gel permeation chromatography (GPC) of 5,000 g / mol or more, 5,500 g / mol or more, 6,000 g / mol or more, 6,500 g / mol or more, 600,000 g / mol or less, 300,000 g / mol or less, 250,000 g / mol or less, or 200,000 g / mol or less, and may also have a weight-average molecular weight (Mw) of 5,000 g / mol or more and 600,000 g / mol or less, 5,500 g / mol or more and 600,000 g / mol or less, 6,000 g / mol or more and 600,000 g / mol or less, 6,500 g / mol or more and 600,000 g / mol or less, 5,000 g / mol or more and 300,000 g / mol or less, or 5,500 g / It may also be 300,000 g / mol or more, 6,000 g / mol or more and 300,000 g / mol or less, 6,500 g / mol or more and 300,000 g / mol or less, 5,000 g / mol or more and 250,000 g / mol or less, 5,500 g / mol or more and 250,000 g / mol or less, 6,000 g / mol or more and 250,000 g / mol or less, 6,500 g / mol or more and 250,000 g / mol or less, 5,000 g / mol or more and 200,000 g / mol or less, 5,500 g / mol or more and 200,000 g / mol or less, 6,000 g / mol or more and 200,000 g / mol or less, or 6,500 g / mol or more and 200,000 g / mol or less.

[0075] The method for producing the polyester polymer according to the above embodiment includes the steps of: adding ethylene glycol and a dicarboxylate compound as described above, reacting them at a temperature of 50°C to 200°C and a pressure of 10 torr to 760 torr to produce an oligomer; and reacting the oligomer at a temperature of 50°C to 200°C and a pressure of 1 torr to produce a polyester polymer. Since bio-based monomers can be used and the equivalent ratio between monomers can be finely adjusted, a polyester polymer with high molecular weight and excellent optical properties can be produced without the use of chain extenders.

[0076] In the method for producing a polyester polymer according to the above embodiment, when adding the ethylene glycol and the dicarboxylate compound, the ethylene glycol and the dicarboxylate compound can be added in an appropriate ratio. For example, the ethylene glycol may be present in an amount of 1.01 moles or more and 1.5 moles or less per mole of the dicarboxylate compound.

[0077] Specifically, the ethylene glycol may be present in amounts of 1.01 moles or more, 1.5 moles or less, 1.4 moles or less, 1.3 moles or less, 1.25 moles or less, 1.2 moles or less, 1.1 moles or less, or 1.01 moles or more and 1.5 moles or less, 1.01 moles or more and 1.4 moles or less, 1.01 moles or more and 1.3 moles or less, 1.01 moles or more and 1.25 moles or less, 1.01 moles or more and 1.2 moles or less, or 1.01 moles or more and 1.1 moles or less per mole of the dicarboxylate compound.

[0078] By adding the dicarboxylate compound and ethylene glycol in the aforementioned ratio, polyester polymers can be produced economically with excellent cost-effectiveness without the need for additional by-products. On the other hand, the polyester polymer may contain repeating units represented by the following chemical formula 1. [ka]

[0079] In the aforementioned chemical formula 1, L1 is an ethylene group, and L2 is an alkylene group having 1 to 10 carbon atoms.

[0080] L1 may be a functional group derived from ethylene glycol, and L2 may be a functional group derived from a dicarboxylate compound.

[0081] L2 may be an alkylene group having 1 to 10 carbon atoms, an alkylene group having 1 to 5 carbon atoms, or an alkylene group having 1 to 3 carbon atoms, and may be, for example, an ethylene group.

[0082] The polyester polymer produced by the method for producing the polyester polymer of the above embodiment may be polyethylene succinate.

[0083] The polyester polymer may contain, with respect to the total repeating units, the repeating units represented by the chemical formula 1 in amounts of 90 mol% or more, 95 mol% or more, 99 mol% or more, 99.9 mol% or more, or 90 mol% or more and 100 mol% or less, 95 mol% or more and 100 mol% or less, 99 mol% or more and 100 mol% or less, or 99.9 mol% or more and 100 mol% or less. For example, the polyester polymer may consist of repeating units represented by the chemical formula 1. In other words, the polyester polymer can contain only ethylene glycol and succinic acid as monomers, and does not contain any other monomers, and therefore can contain only repeating units derived from ethylene glycol and succinic acid.

[0084] On the other hand, the polyester polymer may have a biomass content of 20% or more, as measured by ASTM D6866-22.

[0085] Specifically, the polyester polymer may have a biomass content measured according to ASTM D6866-22 of 20% or more, 50% or more, 90% or more, 95% or more, 98% or more, 99% or more, 100% or less, 99.9% or less, 20% or more and 100% or less, 50% or more and 100% or less, 90% or more and 100% or less, 95% or more and 100% or less, 98% or more and 100% or less, 99% or more and 100% or less, 20% or more and 99.9% or less, 50% or more and 99.9% or less, 90% or more and 99.9% or less, 95% or more and 99.9% or less, 98% or more and 99.9% or less, or 99% or more and 99.9% or less.

[0086] The aforementioned polyester polymer can be produced from a monomer derived from bio, as well as by the polyester polymer production method of other embodiments described later, thereby producing a polyester polymer with a high bio-content.

[0087] For example, if the polyester polymer is derived from a single monomer of bio origin, the polyester polymer may have a biomass content of 20% to 100% or 20% to 99.9% as measured by ASTM D6866-22.

[0088] Alternatively, if the polyester polymer is derived from two types of monomers of bio origin, the polyester polymer may have a biomass content of 90% or more, 95% or more, 98% or more, 99% or more, 100% or less, 99.9% or less, 90% or more and 100% or less, 95% or more and 100% or less, 98% or more and 100% or less, 99% or more and 100% or less, 90% or more and 99.9% or less, 95% or more and 99.9% or less, 98% or more and 99.9% or less, or 99% or more and 99.9% or less.

[0089] The method for producing the polyester polymer according to the above embodiment includes the steps of: adding ethylene glycol and a dicarboxylate compound and reacting them at a temperature of 50°C to 200°C and a pressure of 10 torr to 760 torr to produce an oligomer; and reacting the oligomer at a temperature of 50°C to 200°C and a pressure of 1 torr to produce a polyester polymer. Since bio-based monomers can be used and the equivalent ratio between monomers can be finely adjusted, a polyester polymer with a high bio-content can be produced.

[0090] The biomass content is obtained by graphitizing the polyester polymer and then adding radioactive isotopes. 14 The C content may be calculated according to ASTM D6866-22.

[0091] Since the aforementioned polyester polymer has a biomass content of 90% or more as measured by ASTM D6866-22, it does not contain petroleum-based monomers, thereby achieving carbon neutrality.

[0092] The polyester polymer in the above embodiment may be a biodegradable polyester polymer that exhibits biodegradability.

[0093] In this specification, a biodegradable resin or biodegradable (co)polymer means a resin or (co)polymer that undergoes natural decomposition when exposed to the outside environment, and more specifically, a resin or (co)polymer that undergoes decomposition of 20% by weight or more relative to the original weight of the resin or (co)polymer when exposed to the outside environment for 90 days or more at room temperature (10°C to 30°C).

[0094] According to one embodiment of the present invention, a molded article can be provided that is molded from a resin composition containing the polyester polymer. The resin composition containing the polyester polymer may further contain other additives that improve physical properties in addition to the polyester polymer.

[0095] The molded article may include one or more molded articles selected from the group consisting of injection molded articles, extruded articles, inflation molded articles, fibers, nonwoven fabrics, foams, films, and sheets.

[0096] The applications of the molded product are not significantly limited, but for example, the molded product may be an electronic material, a building material, a food packaging, a food container (disposable cups, trays, etc.), an industrial article, an agricultural article (e.g., mulching film), a nonwoven fabric, a fiber, etc.

[0097] Specifically, a film containing the aforementioned polyester polymer can be provided.

[0098] The film containing the polyester polymer may have a yellowness of 50 or less.

[0099] Specifically, the film containing the polyester polymer may have a yellowness of 1 or more, 10 or more, 15 or more, 50 or less, 48 ​​or less, or 1 to 50 or less, 10 to 50 or less, 15 to 50 or less, 1 to 48 or less, 10 to 48 or less, or 15 to 48 or less.

[0100] The polyester polymer of the above embodiment is produced by the manufacturing method described above, specifically comprising the steps of: adding ethylene glycol and a dicarboxylate compound and reacting them at a temperature of 50°C to 200°C and a pressure of 10 torr to 760 torr to produce an oligomer; and reacting the oligomer at a temperature of 50°C to 200°C and a pressure of 1 torr to produce a polyester polymer; thereby, it is possible to use bio-based monomers, finely adjust the equivalent ratio between monomers, and produce a polyester polymer with excellent optical properties.

[0101] The method for measuring the yellowness is not significantly limited, but for example, it may be a value measured using a Nippon Denshoku colorimeter on a 180 μm thick film containing the polyester polymer, under a viewing angle of 10 degrees. [Effects of the Invention]

[0102] According to the present invention, it is possible to provide a method for producing a polyester polymer having a high bio-content and high molecular weight, as well as excellent optical properties, without using a chain extender, and to provide a polyester polymer. Specific details for carrying out the invention

[0103] The embodiments of the present invention will be described in more detail below with reference to the following examples. However, the following examples are merely illustrative of embodiments of the present invention, and the content of the present invention is not limited to the following examples.

[0104] Example 1 20 g (0.322 mol) of bio-derived ethylene glycol, 37.3 g (0.316 mol) of bio-derived succinic acid, and 0.2 g (1.05 mmol) of p-toluenesulfonic acid were added to an oil bath reactor and mixed. The mixture was then polymerized at 90°C and 50 torr for 2 hours to produce an oligomer.

[0105] Subsequently, the oligomer was further reacted at 90°C and 0.2 torr for 18 hours to produce a polyester polymer.

[0106] Example 2 A polyester polymer was produced in the same manner as in Example 1, except that an oligomer was produced by polymerization reaction at 110°C and 50 torr for 2 hours, and then the oligomer was further reacted at 110°C and 0.2 torr for 18 hours.

[0107] Example 3 A polyester polymer was produced in the same manner as in Example 1, except that an oligomer was produced by polymerization reaction at 130°C and 50 torr for 2 hours, and then the oligomer was further reacted at 130°C and 0.2 torr for 18 hours.

[0108] Example 4 A polyester polymer was produced in the same manner as in Example 1, except that an oligomer was produced by polymerization reaction at 150°C and 50 torr for 2 hours, and then the oligomer was further reacted at 150°C and 0.2 torr for 18 hours.

[0109] Example 5 A polyester polymer was produced in the same manner as in Example 1, except that an oligomer was produced by polymerization reaction at 170°C and 50 torr for 2 hours, and then the oligomer was further reacted at 170°C and 0.2 torr for 18 hours.

[0110] Example 6 A polyester polymer was produced in the same manner as in Example 1, except that an oligomer was produced by polymerization reaction at 190°C and 50 torr for 2 hours, and then the oligomer was further reacted at 190°C and 0.2 torr for 18 hours.

[0111] Example 7 A polyester polymer was produced in the same manner as in Example 1, except that instead of p-toluenesulfonic acid, 0.438 g (1.288 mmol) of titanium butoxide (Ti(buO)4) was added, and the polymerization reaction was carried out at 150°C and 400 torr for 2 hours, then the temperature was raised to 180°C and the polymerization reaction was carried out at 400 torr for 2 hours, and then at 180°C and 10 torr for 2 hours to produce an oligomer, and then the oligomer was further reacted at 180°C and 0.2 torr for 18 hours.

[0112] Example 8 A polyester polymer was produced in the same manner as in Example 1, except that instead of p-toluenesulfonic acid, 0.438 g (1.288 mmol) of titanium butoxide (Ti(buO)4) was added, and the polymerization reaction was carried out at 150°C and 400 torr for 2 hours, then the temperature was raised to 190°C and polymerization reactions were carried out at 400 torr for 2 hours, and then at 190°C and 10 torr for 2 hours to produce an oligomer, and then the oligomer was further reacted at 190°C and 0.2 torr for 18 hours.

[0113] Example 9 A polyester polymer was produced in the same manner as in Example 1, except that instead of p-toluenesulfonic acid, 0.438 g (1.288 mmol) of titanium butoxide (Ti(buO)4) was added, and the polymerization reaction was carried out at 150°C and 400 torr for 2 hours, then the temperature was raised to 200°C and the polymerization reaction was carried out at 400 torr for 2 hours, and then at 200°C and 10 torr for 2 hours to produce an oligomer, and then the oligomer was further reacted at 200°C and 0.2 torr for 18 hours.

[0114] Comparative Example 1 17.36 g (0.279 mol) of non-bio-derived ethylene glycol, 23.6 g (0.199 mol) of non-bio-derived succinic acid, and 20.162 g (0.867 mmol) of SnCl were added to an oil bath reactor and mixed. The mixture was then polymerized at 120°C and 400 torr for 3 hours to produce an oligomer.

[0115] Subsequently, the oligomer was reacted at 170°C and 10 torr for 10 hours, and then the temperature was raised to 230°C and the reaction was further carried out at 0.2 torr for 1 hour to produce a polyester polymer.

[0116] Comparative Example 2 A polyester polymer was produced in the same manner as in Example 1, except that the oligomer was further reacted at 220°C and 0.2 torr for 18 hours using a non-biological monomer.

[0117] Comparative Example 3 20 g (0.322 mol) of bio-derived ethylene glycol, 0.316 mol of dimethyl terephthalate, and 0.438 g (1.288 mmol) of titanium butoxide (Ti(buO)4) were added to an oil bath reactor and mixed. Then, the polymerization reaction was carried out at 50 torr for 2 hours while raising the temperature to 240°C to produce an oligomer.

[0118] Subsequently, the oligomer was further reacted at 0.2 torr for 18 hours while increasing the temperature to 290°C to produce a polyester polymer.

[0119] <Example of experiment> The copolymers produced in the above examples and comparative examples were evaluated for their properties as follows. 1) Evaluation of molecular weight using GPC (gel permeation chromatography) The molecular weight of the copolymers produced in each step of the above examples and comparative examples was evaluated using a Water e2695 model and Agilent Plgel mixed c and b columns. Samples were prepared with chloroform at a solvent concentration of 1 mg / ml and injected in 100 μl increments. Twelve polystyrene standard specimens were used with weight-average molecular weights of 160 g / mol, 580 g / mol, 1180 g / mol, 4,880 g / mol, 9,310 g / mol, 22,790 g / mol, 75,050 g / mol, 217,900 g / mol, 479,200 g / mol, 1,069,000 g / mol, 3,022,000 g / mol, and 6,545,000 g / mol. The weight-average molecular weight, number-average molecular weight, and polydispersity index were measured using gel permeation chromatography (GPC, Tosoh ECO SEC Elite), and the results are shown in Table 1 below. Solvent: Chloroform (eluent) Flow rate: 1.0ml / min Column temperature: 40℃ Standard material: Polystyrene (corrected with a cubic function) [Table 1]

[0120] 2) Bio content After graphitizing the polyester polymers produced in the above examples and comparative examples, radioactive isotopes were added. 14 The C content was analyzed and calculated according to ASTM D6866-22. 3) Yellowness

[0121] The polymer pellets of the polyester polymer produced in the above examples and comparative examples were melted at 130°C for 3 minutes using a hot press to form a film (thickness: 180 μm).

[0122] The yellowness of the aforementioned polyester polymer film (thickness: 180 μm) was measured using a colorimeter manufactured by Nippon Denshoku under the conditions of a D65 light source and a 10-degree viewing angle.

[0123] 4) Biodegradability The polymer pellets of the polyester polymer produced in Examples 3, 4, and 9 and Comparative Examples 1 and 3 were cut into sections with a diameter of 5 mm or less. These sections were placed in the sample holder of a freeze mill, and a stainless steel rod was then inserted. After filling the chamber with liquid nitrogen, the samples were ground at 60 rotations per minute for 10 minutes. The freeze-ground powder was sieved through a 250 μm sieve to prepare samples for biodegradability measurement.

[0124] The biodegradation rate was measured using the aforementioned biodegradation sample at a temperature of 28°C according to the analytical method of ISO 14855-1. At this time, the amount of CO2 generated was measured using an NDIR sensor, and a microbial respiration device (respirometer) was used. [Table 2]

[0125] According to Table 2 above, the polyester polymer in the example achieved a bio-content of 99% by using bio-derived monomers, achieving carbon neutrality. Furthermore, it was confirmed that it possessed high bio-content and molecular weight, as well as low yellowness, even without chain extenders. In contrast, the polyester polymer in the comparative example had a bio-content of 0% compared to the example, failing to achieve carbon neutrality and exhibiting poor optical properties.

Claims

1. It contains repeating units represented by the following chemical formula 1, The biomass content measured by ASTM D6866-22 is 20% or more. A polyester polymer that, when exposed to the external environment at room temperature for 90 days or more, decomposes by 20% or more of its original weight. 【Chemistry 1】 In the aforementioned chemical formula 1, L １ It is an ethylene group, L ２ This is an alkylene group having 1 to 10 carbon atoms.

2. The polyester polymer according to claim 1, wherein the polyester polymer has a number average molecular weight of 1,000 g / mol or more and 200,000 g / mol or less.

3. The polyester polymer according to claim 1, wherein the polyester polymer has a weight-average molecular weight of 5,000 g / mol or more and 600,000 g / mol or less.

4. The polyester polymer according to claim 1, wherein the polyester polymer contains 90 mol% or more of the repeating units represented by the chemical formula 1 with respect to the total repeating units.

5. The polyester polymer according to claim 1, wherein the polyester polymer consists of repeating units represented by the chemical formula 1.

6. A step of adding ethylene glycol and a dicarboxylate compound and reacting them under conditions of a temperature of 50°C to 200°C and a pressure of 10 torr to 760 torr to produce an oligomer; and A method for producing a polyester polymer, comprising the steps of: reacting the oligomer at a temperature of 50°C or higher and 200°C or lower and a pressure of 1 torr or lower to produce a polyester polymer;

7. The method for producing a polyester polymer according to claim 6, wherein when the polyester polymer is exposed to the external environment at room temperature for 90 days or more, 20% or more of the original polymer weight decomposes.

8. The step of adding the ethylene glycol and dicarboxylate compound and reacting them under conditions of a temperature of 50°C to 200°C and a pressure of 10 torr to 760 torr to produce an oligomer; A method for producing a polyester polymer according to claim 6, comprising the step of adding ethylene glycol and a dicarboxylate compound and reacting them for 1 hour to 30 hours at a temperature of 90°C to 200°C and a pressure of 50 torr to 700 torr to produce an oligomer.

9. The step of reacting the oligomer at a temperature of 90°C to 200°C and a pressure of 1 torr or less to produce a polyester polymer; A method for producing a polyester polymer according to claim 6, comprising the step of reacting the oligomer with the oligomer at a temperature of 50°C or more and 200°C or less and a pressure of 1 torr or less for 1 hour or more and 30 hours or less to produce a polyester polymer.

10. The method for producing a polyester polymer according to claim 6, wherein the chain extender is contained in an amount of less than 0.0001 parts by weight per 100 parts by weight of the total of the ethylene glycol and the dicarboxylate compound.

11. The method for producing a polyester polymer according to claim 6, wherein the polyester polymer has a number average molecular weight of 1,000 g / mol or more and 200,000 g / mol or less.

12. The method for producing a polyester polymer according to claim 6, wherein the polyester polymer has a weight-average molecular weight of 5,000 g / mol or more and 600,000 g / mol or less.

13. A method for producing a polyester polymer according to claim 6, wherein the ethylene glycol is contained in an amount of 1.01 moles or more and 1.5 moles or less per mole of the dicarboxylate compound.

14. The method for producing a polyester polymer according to claim 6, wherein the polyester polymer includes repeating units represented by the following chemical formula 1. 【Chemistry 2】 In the aforementioned chemical formula 1, L １ It is an ethylene group, L ２ This is an alkylene group having 1 to 10 carbon atoms.

15. The method for producing a polyester polymer according to claim 14, wherein the polyester polymer contains 90 mol% or more of the repeating units represented by the chemical formula 1 with respect to the total repeating units.

16. The method for producing a polyester polymer according to claim 14, wherein the polyester polymer consists of repeating units represented by the chemical formula 1.

17. The method for producing a polyester polymer according to claim 6, wherein the polyester polymer has a biomass content of 90% or more as measured by ASTM D6866-22.

18. A molded article formed from a resin composition containing the polyester polymer described in claim 1.

19. The molded article according to claim 18, wherein the molded article comprises one or more molded articles selected from the group consisting of injection molded articles, extruded articles, inflation molded articles, fibers, nonwoven fabrics, foams, adhesives, films, and sheets.

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