Polyester copolymer

Abstract

The present invention relates to a polyester copolymer comprising: repeating unit A derived from a first dicarboxylic acid component; repeating unit B derived from a second dicarboxylic acid component; and repeating unit C derived from a first diol component, wherein the polyester copolymer can show enhanced biodegradability while exhibiting softness.

Description

Polyester copolymer

[0001] The present invention relates to a polyester copolymer having biodegradability and controlled flexibility.

[0002] Polyvinyl chloride (PVC) is transparent, has excellent strength, and is used in various industrial fields because its desired physical properties can be easily controlled depending on the type of additives incorporated during processing. For example, by adding plasticizers to PVC with controlled amounts, it is possible to obtain soft PVC, which is used in the manufacture of flexible products such as packaging films and shower curtains, or rigid PVC, which is used in the manufacture of hard products such as plumbing materials.

[0003] However, due to controversy regarding the harmfulness of phthalate-based materials used as plasticizers to the environment and human health, the use of PVC has recently been restricted. Furthermore, since PVC generates dioxins, which are toxic substances, upon combustion, there is no disposal method other than landfilling. Therefore, there is a demand for the development of materials that can replace PVC.

[0004] Meanwhile, polyester is used as a material for manufacturing fibers, films, packaging materials, construction materials, interior and exterior materials, and displays due to its excellent mechanical and optical properties. Polyester is attracting attention as a material that can replace PVC because it is easy to recycle, is more eco-friendly than PVC, and possesses superior mechanical and optical properties.

[0005] However, it is not easy to control the flexibility or rigidity of polyester. Furthermore, the eco-friendliness of polyester is determined by its biodegradability, but there are currently limitations in obtaining polyester with a satisfactory level of biodegradability.

[0006] [Prior Art Literature]

[0007] [Patent Literature]

[0008] (Patent Document 1) Korean Published Patent No. 2003-0016365

[0009] In order to solve the aforementioned conventional problems, the inventors conducted various studies and discovered that when a polyester copolymer is manufactured using a polymerization raw material of a specific composition, the flexibility of the polyester copolymer is controlled while the biodegradability is increased. Specifically, during the process of conducting research on controlling the flexibility of the polyester copolymer, the inventors confirmed that a polyester copolymer in which a cyclohexane structure is introduced possesses biodegradability.

[0010] Therefore, the objective of the present invention is to provide a polyester copolymer that is flexible and biodegradable.

[0011] To solve the above problem, the present invention provides a polyester copolymer comprising a repeating unit A derived from a first dicarboxylic acid component; a repeating unit B derived from a second dicarboxylic acid component; and a repeating unit C derived from a first diol component, wherein the biodegradability measured after 90 days in accordance with UNI EN ISO 14855-1:2013 is 2% or more.

[0012] The polyester copolymer according to the present invention includes specific repeating units (e.g., repeating unit A, repeating unit B, etc.) and can exhibit improved biodegradability while maintaining flexibility as the biodegradability measured after 90 days is controlled to be 2% or higher. Accordingly, since the flexibility of the polyester copolymer is controlled and the impregnation of plasticizers is excellent, it is easy to control the flexibility to the desired level even when using a small amount of plasticizer, and the eco-friendliness can be enhanced due to the improved biodegradability.

[0013] In particular, the above polyester copolymer exhibits excellent printability, emits no harmful chemicals, and possesses flexibility, making it efficient for application as a substitute material for soft PVC, which is subject to issues regarding chlorine and dioxins. For example, the above polyester copolymer can replace PVC in conventional PET / PVC composite materials, such as tarpaulins, thereby enabling unit materialization and enhancing recyclability.

[0014] The present invention will be described in detail below. Hereinafter, the present invention is not limited to the contents described below, but may be modified in various forms as long as the essence of the invention is not altered.

[0015] In this specification, the use of the term "comprising" is intended to specify certain characteristics, regions, steps, processes, elements, and / or components, and unless specifically stated otherwise, it does not exclude the presence or addition of other characteristics, regions, steps, processes, elements, and / or components.

[0016] All numbers and expressions indicating the amounts of components, reaction conditions, etc. described in this specification may be understood to be modified by the term "about" in all cases unless otherwise specified.

[0017] In this specification, terms such as "first," "second," etc. are used to describe various components, and said components are not limited to said terms. These terms are used for the purpose of distinguishing one component from another.

[0018] In this specification, the term "derivative" may refer to a compound in which the introduction of a functional group, oxidation, reduction, or substitution of atoms is performed on a parent compound, and which is modified to the extent that the structure and properties of the parent compound are not significantly altered.

[0019] In this specification, the term "diol component" may refer to a component comprising a monomer having two or more hydroxyl groups (OH) in its molecule and a polymer having hydroxyl groups (OH) prepared using said monomer. Additionally, the term "dicarboxylic acid component" may refer to a component comprising a monomer having two or more carboxyl groups (COOH) and / or carboxylates (COO) in its molecule and a polymer having carboxyl groups (COOH) and / or carboxylates (COO) prepared using said monomer.

[0020]

[0021] Polyester copolymer

[0022] The polyester copolymer according to the present invention comprises specific repeating units (e.g., repeating unit A, repeating unit B, etc.) and exhibits improved biodegradability while having softness. Specifically, the polyester copolymer comprises repeating unit A derived from a first dicarboxylic acid component; repeating unit B derived from a second dicarboxylic acid component; and repeating unit C derived from a first diol component, and has a biodegradability of 2% or more measured after 90 days in accordance with UNI EN ISO 14855-1:2013.

[0023] Repeating unit A derived from the first dicarboxylic acid component may be a repeating unit comprising a terephthalate group, and repeating unit B derived from the second dicarboxylic acid component may be a repeating unit comprising a cyclohexanecarboxylate group.

[0024] According to the present invention, the first dicarboxylic acid component comprises one or more selected from the group consisting of terephthalic acid (TPA), isophthalic acid (IPA), dimethyl terephthalate (DMT), and dimethyl isophthalate (DMI), and the second dicarboxylic acid component may comprise one or more selected from the group consisting of dimethylcyclohexanedicarboxylate (DMCD) and cyclohexanedicarboxylic acid (CHDA). As the first dicarboxylic acid component and the second dicarboxylic acid component each comprise the above components, a polyester copolymer having softness and improved biodegradability can be provided.

[0025] Specifically, the first dicarboxylic acid component may consist of the TPA alone, the IPA alone, the DMT alone, the DMI alone, or a combination thereof. Additionally, the first dicarboxylic acid component may include derivatives of the TPA, derivatives of the IPA, derivatives of the DMT, and / or derivatives of the DMI that are commonly known. Accordingly, the polyester copolymer may include repeating unit A-1 derived from the TPA, repeating unit A-2 derived from the IPA, repeating unit A-3 derived from the DMT, repeating unit A-4 derived from the DMI, or all of these.

[0026] Additionally, the second dicarboxylic acid component may consist solely of the DMCD (e.g., dimethyl 1,4-cyclohexanedicarboxylate, dimethyl 1,3-cyclohexanedicarboxylate, etc.), solely of the CHDA (e.g., 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, etc.), or a combination thereof. Furthermore, the second dicarboxylic acid component may include derivatives of the DMCD and / or derivatives of the CHDA that are commonly known. Accordingly, the polyester copolymer may include repeating unit B-1 derived from the DMCD, repeating unit B-2 derived from the CHDA, or both.

[0027] According to the present invention, the content of repeating unit A derived from a first dicarboxylic acid component comprising one or more of the TPA, IPA, DMT, and DMI may be 10 mol% to 90 mol% based on the total number of repeating units derived from the entire dicarboxylic acid component. Specifically, the content of repeating unit A included in the polyester copolymer may be 10 mol% to 87 mol%, 13 mol% to 85 mol%, 15 mol% to 83 mol%, 17 mol% to 80 mol%, 20 mol% to 75 mol%, or 25 mol% to 60 mol% based on the total number of repeating units derived from the entire dicarboxylic acid component (e.g., first dicarboxylic acid component + second dicarboxylic acid component). A polyester copolymer can be provided that exhibits high biodegradability and flexibility while ensuring productivity (moldability) as the content of the repeating unit A is within the above range.

[0028] In addition, the content of repeating unit B derived from the second dicarboxylic acid component comprising one or more of the DMCD and CHDA may be 10 mol% to 90 mol% based on the total number of repeating units derived from the entire dicarboxylic acid component. Specifically, the content of repeating unit B included in the polyester copolymer may be 10 mol% to 87 mol%, 13 mol% to 85 mol%, 15 mol% to 83 mol%, 17 mol% to 80 mol%, 20 mol% to 75 mol%, or 25 mol% to 60 mol% based on the total number of repeating units derived from the entire dicarboxylic acid component (e.g., first dicarboxylic acid component + second dicarboxylic acid component). As the content of repeating unit B is within the above range, a polyester copolymer can be provided that exhibits high biodegradability and flexibility while ensuring productivity (moldability).

[0029] Meanwhile, the polyester copolymer may further include a repeating unit G derived from a commonly known dicarboxylic acid component (third dicarboxylic acid component). Specifically, the dicarboxylic acid component (third dicarboxylic acid component) may include one or more selected from the group consisting of phthalic acid, phthalic anhydride, 2,6-naphthalene dicarboxylic acid, dimethyl 2,6-naphthalene dicarboxylate, diphenyl dicarboxylic acid, sebacic acid, succinic acid, isodecylic succinic acid, maleic acid, maleic anhydride, fumaric acid, adipic acid, glutaric acid, and azelaic acid.

[0030] The above first diol component is C2~C 10 It includes an alkanediol compound (specifically, a C2-C6 linear alkanediol compound). For example, the first diol component is the C2-C6 10 It can consist of an alkanediol compound alone.

[0031] According to the present invention, the above C 2~ C 10The alkanediol compound may include one or more selected from the group consisting of ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2,2-dimethylpropane-1,3-diol, 1,2-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,2-hexanediol, 1,3-hexanediol, 1,4-hexanediol, 1,6-hexanediol, 2,3-hexanediol, 2,4-hexanediol, 2,5-hexanediol, 2,6-hexanediol, and 3,4-hexanediol. Specifically, the above C2~C 10 The alkanediol compound may be ethylene glycol (EG), 1,4-butanediol (1,4-BD), 2,2-dimethylpropane-1,3-diol (NPG), or a combination thereof.

[0032] The above C2~C 10 The content of repeating unit C derived from the first diol component containing an alkanediol compound may be 10 mol% to 100 mol% based on the total number of moles of repeating units derived from the entire diol component. Specifically, the content of repeating unit C included in the polyester copolymer may be 20 mol% to 100 mol%, 40 mol% to 100 mol%, 50 mol% to 100 mol%, 60 mol% to 100 mol%, 70 mol% to 99 mol%, or 75 mol% to 98 mol% based on the total number of moles of repeating units derived from the entire diol component (e.g., first diol component + second diol component). As the content of repeating unit C is within the above range, a polyester copolymer in which both softness and crystallinity are controlled as intended can be provided.

[0033] Specifically, when the repeating unit C comprises repeating unit C-1 derived from EG, repeating unit C-2 derived from 1,4-BD, and / or repeating unit C-3 derived from NPG, based on the total moles of repeating units derived from the entire diol component, the content of repeating unit C-1 included in the polyester copolymer may be 0 mol% to 100 mol% (e.g., 5 mol% to 100 mol%, 10 mol% to 90 mol%, 30 mol% to 80 mol%, or 45 mol% to 55 mol%), and the content of repeating unit C-2 included in the polyester copolymer may be 0 mol% to 100 mol% (e.g., 5 mol% to 100 mol%, 10 mol% to 90 mol%, 30 mol% to 80 mol%, or 45 mol% to 55 mol%), and the polyester The content of the repeating unit C-3 included in the copolymer may be 0 mol% to 50 mol% (e.g., 0 mol% to 45 mol%, 1 mol% to 40 mol%, 5 mol% to 35 mol%, or 10 mol% to 30 mol%).

[0034] Meanwhile, the polyester copolymer may further include a repeating unit D derived from a second diol component different from the first diol component for controlling softness. Specifically, the second diol component is the C2~C included in the first diol component. 10 It may include a diol compound different from the alkanediol compound. For example, the second diol component may include one or more selected from the group consisting of cyclohexanedimethanol, diethylene glycol, and triethylene glycol.

[0035] The content of repeating unit D derived from the second diol component may be 0 mol% to 40 mol% based on the total number of moles of repeating units derived from the entire diol component. Specifically, the content of repeating unit D included in the polyester copolymer may be 2 mol% to 30 mol%, 3 mol% to 25 mol%, 4 mol% to 25 mol%, or 5 mol% to 20 mol% based on the total number of moles of repeating units derived from the entire diol component (e.g., first diol component + second diol component).

[0036] Additionally, the polyester copolymer may further include repeating unit E derived from the polyester component to control both softness and hardness. Specifically, the polyester component may include polyethylene glycol (PEG), polypropylene glycol (PPG), polytrimethylene ether glycol (PO3G), or polytetramethylene ether glycol (PTMEG).

[0037] The content of repeating unit E derived from the polyester component may be 0 mol% to 10 mol% based on the total number of moles of repeating units derived from the entire diol component. Specifically, the content of repeating unit E included in the polyester copolymer may be 0.1 mol% to 9 mol%, 0.2 mol% to 8 mol%, 0.3 mol% to 7 mol%, or 0.5 mol% to 6 mol% based on the total number of moles of repeating units derived from the entire diol component (e.g., first diol component + second diol component + polyester component).

[0038] In addition, the polyester copolymer may further include repeating unit F derived from a branching agent having three or more functional groups. Due to the branching agent, the polyester copolymer may have the repeating unit F introduced into the side chain of the main chain or have a graft polymerization structure by the repeating unit F, thereby having a high molecular weight.

[0039] The above branching agent is not particularly limited, but specifically may be trimellitic acid, trimellitic anhydride, trimethylol propane, or a combination thereof.

[0040] The polyester copolymer according to the present invention may exhibit improved biodegradability compared to conventional polyester copolymers. Specifically, the polyester copolymer according to the present invention may have a biodegradability of 2% or more when measured after 90 days in accordance with UNI EN ISO 14855-1:2013. More specifically, the biodegradability of the polyester copolymer may be 3% or more, 5% or more, 6% or more, 8% or more, 10% or more, 12% or more, 14% or more, 16% or more, 18% or more, 20% or more, 22% or more, 24% or more, 26% or more, 28% or more, or 30% or more (e.g., 2% to 50%, 4% to 48%, 9% to 45%, 11% to 40%, 13% to 35%, 15% to 30%, or 20% to 25%).

[0041] Meanwhile, according to the present invention, the polyester copolymer may have a glass transition temperature (Tg) of 70 ℃ or lower as measured by differential scanning calorimetry (DSC). Specifically, the glass transition temperature (Tg) of the polyester copolymer may be 65 ℃ or lower, 60 ℃ or lower, 55 ℃ or lower, 50 ℃ or lower, 45 ℃ or lower, 40 ℃ or lower, 35 ℃ or lower, 30 ℃ or lower, or 25 ℃ or lower (e.g., 5 ℃ to 60 ℃, 7 ℃ to 50 ℃, or 9 ℃ to 35 ℃).

[0042] In addition, the polyester copolymer may have a Shore D hardness of less than 80. Specifically, the Shore D hardness of the polyester copolymer may be 20 to 79, 25 to 78, 30 to 77, or 35 to 76.

[0043] In addition, the polyester copolymer may have an intrinsic viscosity (IV) at 35°C of 0.4 dl / g to 1.4 dl / g, 0.5 dl / g to 1.3 dl / g, 0.52 dl / g to 1.28 dl / g, or 0.55 dl / g to 1.25 dl / g. Processability of the polyester copolymer can be ensured as the intrinsic viscosity is within the above range.

[0044] In addition, the polyester copolymer may have a biodegradation index (BI) of 30 or less according to Formula 1 below. As the biodegradation index (BI) is controlled to be 30 or less, the biodegradability of the polyester copolymer can be secured. Specifically, the biodegradation index (BI) may be 28 or less, 25 or less, 23 or less, 20 or less, 18 or less, 16 or less, 14 or less, 12 or less, 10 or less, 8 or less, 6 or less, 4 or less, or 3 or less (e.g., 1 to 20, 2 to 16, or 5 to 12).

[0045] [Equation 1]

[0046] BI = (P T + P D ) / P B

[0047] In the above Equation 1,

[0048] P T is the glass transition temperature (Tg) of the above polyester copolymer, and

[0049] P D is the Shore D hardness of the above polyester copolymer, and

[0050] P B is the biodegradability of the above polyester copolymer.

[0051] These polyester copolymers may be block copolymers or random copolymers and may be manufactured in the form of chips, pellets, or powder.

[0052] Specifically, the polyester copolymer according to the present invention can be manufactured by obtaining a product by subjecting a polymerization raw material to a conventionally known esterification reaction or ester exchange reaction, and then subjecting the obtained product to a polycondensation reaction.

[0053] The above esterification reaction or ester exchange reaction can be carried out by introducing the polymerization raw material into a batch reactor or a continuous reactor and controlling the reaction temperature, reaction pressure and / or reaction time.

[0054] Specifically, the esterification reaction or transesterification reaction is carried out at atmospheric pressure, or 0.1 kg / cm² relative to atmospheric pressure. 2 up to 3.0 kg / cm² 2 It can be carried out for 2 to 12 hours at a pressure of that high pressure and a temperature of 180 ℃ to 275 ℃. For example, the esterification reaction can be carried out for 3 to 11 hours, 3 to 10 hours, 4 to 8 hours, or 5 to 6 hours at a temperature of 185 ℃ to 270 ℃, 190 ℃ to 260 ℃, 190 ℃ to 250 ℃, or 195 ℃ to 240 ℃. In addition, the above ester exchange reaction may be carried out at a temperature of 185 ℃ to 260 ℃, 190 ℃ to 250 ℃, 190 ℃ to 240 ℃, or 195 ℃ to 220 ℃ for 2 to 10 hours, 2 to 8 hours, 2 to 6 hours, or 3 to 4 hours.

[0055] The above polymerization raw material comprises the above-described first dicarboxylic acid component, second dicarboxylic acid component, and first diol component, and optionally further comprises the above-described third dicarboxylic acid component, second diol component, or polyester component. By using such a polymerization raw material, a polyester copolymer having softness and improved biodegradability can be manufactured.

[0056] Meanwhile, the above polymerization raw material may further include one or more additives selected from the group consisting of commonly known catalysts, colorants, crystallizing agents, antioxidants, stabilizers, and branching agents.

[0057] The above catalyst may be a methylate of sodium or magnesium; an acetate, borate, fatty acid salt, or carbonate of Zn, Cd, Mn, Co, Ca, Ba, etc.; or an oxide or hydrate of Mg, Pb, Mn, Ti, Si, Sb, Sn, Al, etc. For example, the above catalyst may be tetraethyl titanate, acetyltripropyl titanate, tetrapropyl titanate, tetrabutyl titanate, 2-ethylhexyl titanate, octylene glycol titanate, triethanolamine titanate, ethyl acetoacetic ester titanate, isostearyl titanate, titanium dioxide, germanium dioxide, germanium tetrachloride, germanium ethylene glycoside, germanium acetate, or a combination thereof.

[0058] Organic compounds such as cobalt-based compounds, anthraquinone-based compounds, perinone-based compounds, azo-based compounds, and methine-based compounds (e.g., cobalt acetate, cobalt propionate, Clariant’s Polysynthren Blue RLS, Clariant’s Solvaperm Red BB) may be used as the above-mentioned colorants.

[0059] The above crystallizing agent may include a crystallization nucleating agent, a UV absorber, a polyolefin resin, a polyamide resin, etc.

[0060] The above antioxidants may include hindered phenolic compounds, phosphite compounds, thioether compounds, etc.

[0061] Phosphorus-based compounds such as phosphoric acid, trimethylphosphate, and triethylphosphate may be used as the above-mentioned stabilizer.

[0062] Trimellitic acid, trimellitic anhydride, trimethylol propane, or a combination thereof may be used as the above branching agent.

[0063] The above polycondensation reaction can be carried out by introducing the product (oligomer) into a batch reactor or a continuous reactor and controlling the reaction temperature and / or reaction pressure.

[0064] Specifically, the polycondensation reaction can be carried out for 1 to 10 hours at a pressure of 0.01 mmHg to 400 mmHg and a temperature of 220 ℃ to 290 ℃. For example, the polycondensation reaction may be carried out for 1 to 8 hours, or 2 to 6 hours, at a pressure of 0.01 mmHg to 200 mmHg, 0.05 mmHg to 100 mmHg, 0.1 mmHg to 50 mmHg, 0.2 mmHg to 10 mmHg, 0.2 mmHg to 3 mmHg, 0.3 mmHg to 1.5 mmHg, or 0.5 mmHg to 1.2 mmHg and a temperature of 225 ℃ to 285 ℃, 230 ℃ to 280 ℃, 230 ℃ to 250 ℃, 255 ℃ to 285 ℃, or 250 ℃ to 280 ℃.

[0065]

[0066] The present invention will be explained in more detail through the following examples. However, the following examples are merely illustrative of the present invention and do not limit the scope of the present invention.

[0067]

[0068] [Example]

[0069] Preparation of polyester copolymer

[0070] Example 1

[0071] (1) Esterification reaction

[0072] 511 g (3.075 mol) of terephthalic acid (TPA), 2,462 g (12.299 mol) of dimethylcyclohexanedicarboxylate (DMCD), and 1,908 g (30.74 mol) of ethylene glycol (EG) were added to a 10 L reactor connected to a column and a condenser capable of cooling with water. At this time, the molar ratio of G / A (total diol / total diacid) was 2.0. Subsequently, 0.853 g of tetrabutyl titanate (TBT) as a catalyst, 0.235 g of phosphoric acid as a stabilizer, and 1.47 g of trimellitic anhydride as a branching agent were added and stirred.

[0073] Next, nitrogen is injected into the reactor so that the pressure in the reactor is 1.0 kgf / cm² relative to atmospheric pressure. 2The reactor was subjected to a high pressurization state (absolute pressure: 1495.6 mmHg). Subsequently, the temperature of the reactor was raised from room temperature to 200 ℃ over 60 minutes, maintained at 200 ℃ for 2 hours, and then raised again to 245 ℃ over 5 hours. Afterward, the esterification reaction was carried out at a temperature of 245 ℃ for 0.5 hours. During this process, byproducts were discharged through a column and a condenser. Once the esterification reaction was completed, the nitrogen inside the pressurized reactor was purged to lower the reactor pressure to atmospheric pressure, and the product inside the reactor was transferred to a 7L volume reactor capable of vacuum reaction.

[0074] (2) Polycondensation reaction

[0075] The pressure of the reactor into which the product obtained through the above esterification reaction was introduced was reduced from atmospheric pressure to 5.0 Torr (absolute pressure: 5 mmHg) over 30 minutes, and at the same time, the temperature of the reactor was increased to 270 ℃ over 1 hour, and then the polycondensation reaction was carried out while maintaining the pressure of the reactor at 1.0 Torr (absolute pressure: 1.0 mmHg) or lower. The polycondensation reaction was carried out while appropriately adjusting the stirring speed until the intrinsic viscosity (IV) of the reaction product (molten material) inside the reactor became 1.0 dl / g or higher, after which the reaction product was discharged outside the reactor and formed into a strand, and then solidified with a cooling liquid and granulated to an average weight of about 12 mg to 14 mg to produce a polyester copolymer.

[0076]

[0077] Examples 2 to 6

[0078] A polyester copolymer was prepared in the same manner as in Example 1, except that the raw material components and their content were applied as shown in Table 1 below, and the conditions of the esterification reaction (or ester exchange reaction) and polycondensation reaction were adjusted according to the raw material components.

[0079]

[0080] Comparative Examples 1 to 2

[0081] A polyester copolymer was prepared in the same manner as in Example 1, except that the raw material components and their content were applied as shown in Table 1 below, and the conditions of the esterification reaction (or ester exchange reaction) and polycondensation reaction were adjusted according to the raw material components.

[0082]

[0083] Classification Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Comparative Example 1 Comparative Example 2 TPA(g)511 g 1,022 g 1,533 g 1,788 g 1,533 g 2,043 g 2,554 g 2,554 g DMCD (g)2,462 g 1,847 g 1,231 g 923 g 1,231 g 616 g--EG(g)1,908 g 1,908 g 954 g 954 g-477 g 1,908 g 1,336 g 1,4-BD(g)--416 g 693 g 1,801 g 1,219 g--NPG (g)--320 g-----CHDM (g)-------665 gPTMEG (g)-----615 g--Catalyst(g)TBT0.853 g0.853 g0.853 g0.853 g0.853 g0.853 g--Sb2O3------0.853 g0.853 g Stabilizer(g)0.235 g0.235 g0.235 g0.235 g0.235 g0.235 g0.235 g 0.235 g Stabilizer(g)1.47 g1.47 g1.47 g1.47 g1.47 g1.47 g--

[0084]

[0085] [Experimental Example]

[0086] Experimental Example 1: Composition of polyester copolymer

[0087] Each of the polyester copolymers of Examples 1 to 6 and Comparative Examples 1 to 2 was dissolved in CDCl3 solvent at a concentration of 3 mg / mL, and then the composition of the polyester copolymer (mol% of repeating units) was confirmed through the 1H-NMR spectrum obtained using a nuclear magnetic resonance device (JEOL, 600 MHz FT-NMR) at 25 °C.

[0088]

[0089] Experimental Example 2: Tg

[0090] For each of the polyester copolymers of Examples 1 to 6 and Comparative Examples 1 to 2, the glass transition temperature (Tg) was measured using a differential scanning calorimeter (DSC). Specifically, using a differential scanning calorimeter, a first scan was obtained by increasing the temperature from -40 ℃ to 280 ℃ by 10 ℃ and maintaining it at 280 ℃ for 2 minutes, then decreasing the temperature from 280 ℃ to -20 ℃ to -300 ℃ and maintaining it for 5 minutes, and then increasing the temperature again from -40 ℃ to 280 ℃ by 10 ℃ to obtain a second scan. The glass transition temperature (Tg) was analyzed from the heat flow curve obtained during the above process.

[0091]

[0092] Experimental Example 3: Shore D Hardness

[0093] Each of the polyester copolymers of Examples 1 to 6 and Comparative Examples 1 to 2 was pressed with a hot press to produce flat specimens with a thickness of 1 mm. At this time, the pressing temperature for Examples 1 to 6 and Comparative Example 2 was 220 ℃, and the pressing temperature for Comparative Example 1 was 250 ℃. Subsequently, the Shore D hardness of the prepared specimens was measured according to ASTM D2240-05.

[0094]

[0095] Experimental Example 4: Biodegradability

[0096] For each of the polyester copolymers of Examples 1 to 6 and Comparative Examples 1 to 2, the biodegradability over 90 days was measured in accordance with UNI EN ISO 14855-1:2013. Specifically, the polyester copolymer samples were freeze-ground to form particles of 20 μm or less, and then the particles were mixed into a culture medium composed of urea, starch, inorganic materials, etc., according to a standard method. The amount of carbon dioxide released over 90 days was measured while maintaining a constant temperature of 58 ℃ to calculate the biodegradability based on weight change.

[0097]

[0098] Composition Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Comparative Example 1 Comparative Example 2 Dicarboxylic acid component-derived repeating unit (mol%) TPA 20 40 60 70 60 80 100 100 DM CD 80 60 40 30 40 2000 Diol component-derived repeating unit (mol%) EG 100 100 50 500 101 00 70 1,4-BD 00 30 50 100 88 00 NPG 00 200 0000 CH DM 00 00 00 30 Polyester component-derived repeating unit (mol%) PTME G 00 00 200 Tg (°C) 25 40 31 35 9 20 80 80 Shore D Hardness 50 79 77 78 75 68 80 80 Biodegradability (%) 14 87 15 22 24 < 1 < 1B.I.5.3614.8815.437.533.823.67< 160< 160

[0099] Referring to Table 2 above, it can be confirmed that the polyester copolymers of Examples 1 to 6 according to the present invention exhibit a biodegradability of 5% or more, which is superior to the polyester copolymers of Comparative Examples 1 and 2. In addition, it can be confirmed that they have low crystallinity with a Tg of 70°C or lower and softness with a Shore D hardness of less than 80.

Claims

1. Repeating unit A derived from the first dicarboxylic acid component; Repeating unit B derived from the second dicarboxylic acid component; and It comprises repeating unit C derived from the first diol component, and Polyester copolymer having a biodegradability of 2% or more measured after 90 days in accordance with UNI EN ISO 14855-1:2013.

2. In Paragraph 1, The first dicarboxylic acid component comprises one or more selected from the group consisting of terephthalic acid (TPA), isophthalic acid (IPA), dimethyl terephthalate (DMT), and dimethyl isophthalate (DMI), and A polyester copolymer comprising one or more selected from the group consisting of dimethylcyclohexanedicarboxylate (DMCD) and cyclohexanedicarboxylic acid (CHDA) as the second dicarboxylic acid component.

3. In Paragraph 2, A polyester copolymer having a content of repeating unit A of 10 mol% to 90 mol% and a content of repeating unit B of 10 mol% to 90 mol% based on the total molar amount of repeating units derived from the entire dicarboxylic acid component.

4. In Paragraph 1, The above first diol component C2~C 10 Polyester copolymer containing an alkanediol compound.

5. In Paragraph 4, The above C2~C 10 A polyester copolymer comprising one or more alkanediol compounds selected from the group consisting of ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2,2-dimethylpropane-1,3-diol, 1,2-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,2-hexanediol, 1,3-hexanediol, 1,4-hexanediol, 1,6-hexanediol, 2,3-hexanediol, 2,4-hexanediol, 2,5-hexanediol, 2,6-hexanediol, and 3,4-hexanediol.

6. In Paragraph 4, A polyester copolymer having a content of repeating unit C of 10 mol% to 100 mol% based on the total molar amount of repeating units derived from the entire diol component.

7. In Paragraph 1, A polyester copolymer further comprising a repeating unit D derived from a second diol component different from the first diol component.

8. In Paragraph 7, A polyester copolymer comprising one or more of the second diol components selected from the group consisting of cyclohexanedimethanol, diethylene glycol, and triethylene glycol.

9. In Paragraph 1, A polyester copolymer further comprising a repeating unit E derived from a polyester component comprising polyethylene glycol (PEG), polypropylene glycol (PPG), polytrimethylene ether glycol (PO3G), or polytetramethylene ether glycol (PTMEG).

10. In Paragraph 1, A polyester copolymer further comprising a repeating unit F derived from a branching agent having three or more functional groups.

11. In Paragraph 1, Polyester copolymer having a glass transition temperature (Tg) of 70°C or less as measured by differential scanning calorimetry (DSC).

12. In Paragraph 1, Polyester copolymer with a Shore D hardness of less than 80.

13. In Paragraph 1, Polyester copolymer having a biodegradability index (BI) of 30 or less according to Formula 1 below: [Equation 1] B.I. = (P T + P D ) / P B In the above Equation 1, P T is the glass transition temperature (Tg) of the above polyester copolymer, and P D is the Shore D hardness of the above polyester copolymer, and P B is the biodegradability of the above polyester copolymer.