Recycled polyester resin and article manufactured therefrom

Abstract

The present invention relates to a recycled polyester resin and an article manufactured therefrom, wherein the recycled polyester resin comprises repeat unit A derived from a recycled raw material, and the recycled raw material comprises at least one of a recycled diol component and a recycled acid component. The recycled polyester resin can exhibit eco-friendliness while being excellent in quality such as heat resistance and color.

Description

Recycled polyester resin and articles manufactured therefrom

[0001] The present invention relates to a recycled polyester resin capable of exhibiting excellent quality (e.g., heat resistance, color, etc.) even when manufactured using recycled raw materials, and to an article manufactured from said recycled polyester resin.

[0002] Among the types of polymers closely utilized in modern life, polyester is widely used as a material for beverage or food containers; various packaging films; or various interior and exterior materials such as panels, shelves, and partitions, due to its excellent mechanical strength, heat resistance, transparency, and gas barrier properties.

[0003] Due to the aforementioned widespread use, plastic waste such as polyester is generated annually in unmanageable quantities, and recently, countries around the world are establishing regulations and measures regarding the recycling of waste plastic resources, including waste polyester.

[0004] There are physical or chemical methods for recycling the waste polyester mentioned above, but physical recycling methods are not widely applied because they cannot guarantee purity. Meanwhile, chemical recycling methods involve breaking the ester bonds of waste polyester to perform depolymerization, utilizing reactions such as glycolysis, hydrolysis, methanolysis, and aminolysis. Recycled raw materials can be obtained from waste polyester through the depolymerization process using the above reactions.

[0005] However, the recycled raw material obtained through the aforementioned depolymerization process has low purity, which presents a problem in that recycled polyester manufactured using it is difficult to exhibit the required quality (e.g., heat resistance, color). Specifically, unwanted side reactions occur during the depolymerization process, generating by-products, which act as impurities and reduce the purity of the recycled raw material.

[0006] To address the aforementioned problems, attempts are being made to increase the purity of recycled raw materials through various purification processes, but they still fail to achieve a satisfactory level.

[0007] [Prior Art Literature]

[0008] [Patent Literature]

[0009] (Patent Document 1) Republic of Korea Published Patent Application No. 2022-0138819

[0010] In order to solve the aforementioned conventional problems, the inventors conducted various studies and, as a result, confirmed that when using recycled raw materials with controlled specific components in the production of recycled polyester resin using recycled raw materials obtained through the depolymerization process of waste polyester, a recycled polyester resin of excellent quality (e.g., heat resistance, color, etc.) is produced while exhibiting a carbon reduction effect.

[0011] Accordingly, the objective of the present invention is to provide a recycled polyester resin capable of exhibiting excellent quality (e.g., heat resistance, color, etc.) even when manufactured using recycled raw materials, and an article manufactured using the same.

[0012] To solve the above problem, the present invention provides a recycled polyester resin comprising a repeating unit A derived from a recycled raw material, wherein the recycled raw material comprises one or more of a recycled diol component and a recycled acid component, wherein the content of an organic acid-containing compound measured by ion chromatography of the recycled diol component is 300 ppm or less, and the content of an organic acid-containing compound measured by ion chromatography of the recycled acid component is 5 ppm or less.

[0013] In addition, the present invention provides an article manufactured from the recycled polyester resin.

[0014] In addition, the present invention provides a method for manufacturing a recycled polyester resin comprising the step of introducing a polymerization raw material containing a recycled raw material into a reactor and polymerizing it, wherein the recycled raw material comprises one or more of a recycled diol component and a recycled acid component, wherein the content of an organic acid-containing compound measured by ion chromatography of the recycled diol component is 300 ppm or less, and the content of an organic acid-containing compound measured by ion chromatography of the recycled acid component is 5 ppm or less.

[0015] The recycled polyester resin according to the present invention may have excellent quality, such as heat resistance and color, as it contains repeating unit A derived from recycled raw materials, which includes one or more of a recycled diol component and a recycled acid component, each having an organic acid-containing compound content controlled to be below a specific range. In addition, the recycled polyester resin may exhibit eco-friendliness (carbon reduction effect) because the amount of CO2 emitted during the manufacturing process is reduced compared to a virgin polyester resin made solely from virgin raw materials.

[0016] Therefore, when various articles are manufactured using the recycled polyester resin according to the present invention, high-quality articles can be provided in an environmentally friendly manner.

[0017] 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.

[0018] In this specification, the use of the word “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.

[0019] 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.

[0020]

[0021] Unlike virgin raw materials obtained through general chemical processes, recycled raw materials produced through the chemical recycling of waste polyester contain various by-products that act as impurities. Therefore, in order to increase the purity of the recycled raw materials and obtain recycled polyester resin of excellent quality, it is necessary to control these by-products.

[0022] Accordingly, the inventors conducted research on controlling the above-mentioned by-products and confirmed that among various by-products, organic acid-containing compounds have a significant impact on the quality of recycled polyester resin. Specifically, during the depolymerization process of waste polyester, dehydration reactions of glycol-based compounds (e.g., ethylene glycol) or oxidation reactions of glucose may occur, and through these reactions, organic acid-containing compounds such as formic acid and / or formate are generated as impurities. These organic acid-containing compounds generated in this way alter the acidity of the recycled raw material, and when recycled polyester resin is manufactured using recycled raw material with altered acidity, quality degradation occurs; thus, the inventors concluded that it is important to control the content of organic acid-containing compounds.

[0023] In addition, the inventors confirmed that when recycled polyester resin is manufactured using recycled raw materials with controlled organic acid-containing compound content, a carbon reduction effect is observed compared to when polyester resin is manufactured using only virgin raw materials.

[0024] Therefore, the present invention aims to provide a recycled polyester resin manufactured using recycled raw materials in which the content of organic acid-containing compounds is controlled, and this is described in detail as follows.

[0025]

[0026] Recycled polyester resin

[0027] The recycled polyester resin of the present invention comprises repeating unit A derived from a recycled raw material, wherein the recycled raw material comprises one or more of a recycled diol component and a recycled acid component, wherein the content of an organic acid-containing compound measured by ion chromatography of the recycled diol component is 300 ppm or less, and the content of an organic acid-containing compound measured by ion chromatography of the recycled acid component is 5 ppm or less.

[0028] According to the present invention, the content of repeating unit A derived from the recycled raw material is not particularly limited, but may be 15% by weight or more based on the total weight of the recycled polyester resin. The content of repeating unit A may refer to the content (input amount) of the recycled raw material. For example, the polymerization raw material for manufacturing the recycled polyester resin includes the recycled raw material, and in this case, the content of the recycled raw material may be 15% by weight or more based on the total weight of the polymerization raw material.

[0029] Specifically, the content of repeating unit A (content of recycled raw material) included in the recycled polyester resin may be 17 wt% or more, 20 wt% or more, 25 wt% or more, 30 wt% or more, 35 wt% or more, 40 wt% or more, 45 wt% or more, 50 wt% or more, 55 wt% or more, 60 wt% or more, 65 wt% or more, 70 wt% or more, 75 wt% or more, 80 wt% or more, 85 wt% or more, 90 wt% or more, or 95 wt% or more (e.g., 15 to 100 wt%, 26 to 99 wt%, 32 to 98 wt%, 46 to 97 wt%, or 73 to 96 wt%) based on the total weight of the recycled polyester resin. As the content of repeating unit A is within the above range, a recycled polyester resin of excellent quality can be provided in an environmentally friendly manner.

[0030] The above-mentioned regenerated raw material may include either one of the above-mentioned regenerated diol component and the above-mentioned regenerated acid component, or may include both.

[0031] Specifically, when considering the carbon reduction effect, the recycled raw material may include both the recycled diol component and the recycled acid component. Accordingly, the repeating unit A includes repeating unit A-1 derived from the recycled diol component and repeating unit A-2 derived from the recycled acid component.

[0032] According to the present invention, the recycled raw material comprises a recycled diol component and / or a recycled acid component in which the content of an organic acid-containing compound, which is a specific component, is controlled. Specifically, the content of the organic acid-containing compound measured by ion chromatography of the recycled diol component is 300 ppm or less, and the content of the organic acid-containing compound measured by ion chromatography of the recycled acid component is 5 ppm or less. By manufacturing a recycled polyester resin using the recycled diol component and the recycled acid component, in which the content of the organic acid-containing compound is controlled to be below the specific range as described above, a recycled polyester resin with excellent color and heat resistance can be provided, while achieving a carbon reduction effect.

[0033] The content of the organic acid-containing compound included in the above-mentioned regenerated diol component may specifically be 250 ppm or less, 200 ppm or less, 150 ppm or less, 100 ppm or less, 80 ppm or less, or 50 ppm or less (e.g., 0 to 300 ppm, greater than 0 to 250 ppm, 1 to 180 ppm, 5 to 150 ppm, 10 to 130 ppm, 30 to 100 ppm, or 50 to 80 ppm). The content of the organic acid-containing compound included in the above-mentioned regenerated acid component may specifically be 4.5 ppm or less, 4 ppm or less, 3 ppm or less, 2 ppm or less, or 1 ppm or less (e.g., 0 to 5 ppm, greater than 0 to 3.5 ppm, 0.1 to 2.5 ppm, 0.3 to 1.8 ppm, 0.5 to 1.5 ppm, 0.7 to 1.3 ppm, or 0.8 to 1 ppm).

[0034] The above organic acid-containing compound may include a commonly known organic acid or a salt thereof. Specifically, the above organic acid-containing compound may include formic acid, formate, or a combination thereof.

[0035] According to the present invention, the regenerated diol component may comprise one or more (specifically two or more, three or more, or four or more) selected from the group consisting of regenerated ethylene glycol, regenerated cyclohexanedimethanol, regenerated cyclohexanedimethanol derivatives (e.g., regenerated 4-(hydroxymethyl)cyclohexylmethyl-4-(hydroxymethyl)cyclohexanecarboxylate, regenerated 4-(4-(hydroxymethyl)cyclohexylmethoxymethyl)cyclohexylmethanol), regenerated neopentyl glycol, regenerated isosorbide, regenerated diethylene glycol, and regenerated bis-2-hydroxyethyl terephthalate.

[0036] The content of the recycled ethylene glycol included in the recycled diol component is not particularly limited, but may be 1 to 90 weight%, 5 to 85 weight%, 10 to 75 weight%, or 15 to 65 weight% based on the total weight of the recycled diol component.

[0037] The content of the regenerated cyclohexanedimethanol included in the regenerated diol component is not particularly limited, but may be 1 to 90 weight%, 5 to 85 weight%, 10 to 75 weight%, or 15 to 65 weight% based on the total weight of the regenerated diol component.

[0038] The content of the regenerated cyclohexanedimethanol derivative included in the regenerated diol component is not particularly limited, but may be 1 to 20 weight%, 2 to 15 weight%, 5 to 15 weight%, or 5 to 10 weight% based on the total weight of the regenerated diol component.

[0039] The content of the regenerated neopentyl glycol included in the regenerated diol component is not particularly limited, but may be 1 to 50 weight%, 2 to 45 weight%, 5 to 40 weight%, or 5 to 30 weight% based on the total weight of the regenerated diol component.

[0040] The content of the regenerated isosorbide included in the regenerated diol component is not particularly limited, but may be 0.1 to 50 weight%, 1 to 45 weight%, 1 to 40 weight%, or 1 to 30 weight% based on the total weight of the regenerated diol component.

[0041] The content of the recycled diethylene glycol included in the recycled diol component is not particularly limited, but may be 1 to 30 weight%, 5 to 25 weight%, 5 to 20 weight%, or 5 to 15 weight% based on the total weight of the recycled diol component.

[0042] The content of the regenerated bis-2-hydroxyethyl terephthalate included in the regenerated diol component is not particularly limited, but may be 1 to 99 weight%, 5 to 95 weight%, 10 to 90 weight%, or 15 to 90 weight% based on the total weight of the regenerated diol component.

[0043] According to the present invention, the regenerated acid component may include a regenerated dicarboxylic acid, but is not limited thereto. Specifically, the regenerated acid component may include one or more selected from the group consisting of regenerated terephthalic acid, regenerated isophthalic acid, regenerated dimethyl phthalate, and regenerated dimethyl terephthalate. More specifically, the regenerated acid component may include regenerated terephthalic acid, regenerated isophthalic acid, or a combination thereof.

[0044] The content of the regenerated terephthalic acid included in the regenerated acid component is not particularly limited, but may be 1 to 99 weight%, 5 to 95 weight%, 10 to 90 weight%, or 15 to 90 weight% based on the total weight of the regenerated acid component.

[0045] The content of the regenerated isophthalic acid included in the regenerated acid component is not particularly limited, but may be 1 to 30 weight%, 2 to 25 weight%, 5 to 20 weight%, or 5 to 15 weight% based on the total weight of the regenerated acid component.

[0046] Meanwhile, the recycled polyester resin of the present invention may further include repeating unit B derived from a virgin raw material comprising one or more of a diol component (virgin diol component) and an acid component (virgin acid component). As the recycled polyester resin further includes the repeating unit B, the quality can be further improved and a carbon reduction effect can be achieved.

[0047] Specifically, when considering the quality of the recycled polyester resin, the virgin raw material may contain both the diol component and the acid component. Accordingly, the repeating unit B includes repeating unit B-1 derived from the diol component and repeating unit B-2 derived from the acid component.

[0048] The content of repeating unit B derived from the virgin raw material included in the recycled polyester resin is not particularly limited, but may be 0 to 95 weight%, 1 to 80 weight%, 2 to 60 weight%, 3 to 40 weight%, or 4 to 10 weight% based on the total weight of the recycled polyester resin.

[0049] According to the present invention, the diol component is ethylene glycol, cyclohexanedimethanol, cyclohexanedimethanol derivative (e.g., 4-(hydroxymethyl)cyclohexylmethyl-4-(hydroxymethyl)cyclohexanecarboxylate, 4-(4-(hydroxymethyl)cyclohexylmethoxymethyl)cyclohexylmethanol), neopentyl glycol, isosorbide, diethylene glycol, bis-2-hydroxyethyl terephthalate, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, 2-methylene-1,3-propanediol, 2-ethyl-1,3-propanediol, 2-isopropyl-1,3-propanediol, 1,4-butanediol, 2,3-butanediol, 3-methyl-1,5-pentanediol, It may include one or more selected from the group consisting of 3-methyl-2,4-pentanediol, 1,6-hexanediol, 1,2-cyclohexanediol, and 1,4-cyclohexanediol (specifically, two or more, three or more, or four or more). Preferably, the diol component may include one selected from the group consisting of ethylene glycol, cyclohexanedimethanol, cyclohexanedimethanol derivatives, neopentyl glycol, isosorbide, diethylene glycol, and bis-2-hydroxyethyl terephthalate (specifically, two or more, or three or more).

[0050] In addition, the acid component may include a dicarboxylic acid, but is not limited thereto. Specifically, the acid component may include one or more selected from the group consisting of terephthalic acid, isophthalic acid, dimethyl isophthalate, dimethyl phthalate, dimethyl terephthalate, phthalic acid, phthalic anhydride, 2,6-naphthalene dicarboxylic acid, dimethyl 2,6-naphthalene dicarboxylate, diphenyl dicarboxylic acid, 1,4-cyclohexane dicarboxylic acid, 1,3-cyclohexane dicarboxylic acid, dimethyl 1,4-cyclohexane dicarboxylate, dimethyl 1,3-cyclohexane dicarboxylate, sebacic acid, succinic acid, isodecylic succinic acid, maleic acid, maleic anhydride, fumaric acid, adipic acid, glutaric acid, and azelaic acid. Preferably, the acid component may include terephthalic acid, isophthalic acid, or a combination thereof.

[0051] According to the present invention, the recycled polyester resin can exhibit an excellent carbon reduction effect. In particular, the recycled polyester resin can have excellent eco-friendliness as the amount of CO2 generated during the manufacturing process is significantly reduced compared to the virgin polyester resin. Specifically, when the amount of CO2 generated per 1 kg of production is evaluated by Life Cycle Assessment (LCA) according to ISO 14000, the recycled polyester resin may have a CO2 reduction ratio of 5% or more compared to the virgin polyester resin. Specifically, the CO2 reduction ratio may be 6% or more, 8% or more, 12% or more, 14% or more, 15% or more, 18% or more, 20% or more, 25% or more, 30% or more, 33% or more, 35% or more, or 40% or more (e.g., 5 to 50%, 7 to 45%, or 10 to 40%).

[0052] The above-mentioned Life Cycle Assessment (LCA) verifies the CO2 emissions generated until the production of recycled polyester resin from polymerization raw materials (recycled raw materials alone, or a mixture of recycled and virgin raw materials), thereby allowing for the calculation of the global warming potential and verification of carbon reduction effects.

[0053] According to the present invention, the recycled polyester resin may have an intrinsic viscosity (IV) of 0.5 to 1.2 dl / g at 35°C. Specifically, the intrinsic viscosity of the recycled polyester resin may be 0.53 to 1.15 dl / g, 0.55 to 1.13 dl / g, 0.6 to 1.1 dl / g, 0.63 to 1.0 dl / g, 0.65 to 0.9 dl / g, or 0.65 to 0.85 dl / g. The intrinsic viscosity may refer to melt intrinsic viscosity or solid intrinsic viscosity. Processability of the recycled polyester resin can be ensured as the intrinsic viscosity is within the above range.

[0054] According to the present invention, the recycled polyester resin can exhibit a transmittance of 80% or more when injection molded to a thickness of 6 mm and the transmittance is measured. Specifically, when the recycled polyester resin is injection molded to produce an injection specimen with a thickness of 6 mm and the transmittance of the produced injection specimen is measured according to ASTM D1003, the injection specimen (recycled polyester resin injection specimen) may have a transmittance of 80% or more, 81% or more, 83% or more, 85% or more, 86% or more, 87% or more, or 88% or more (e.g., 80 to 98%, 83 to 93%, or 85 to 90%).

[0055] The recycled polyester resin of the present invention may have a state such as chips, pellets, or powder.

[0056] The recycled polyester resin of the present invention may be a homopolymer or a copolymer. Specifically, the recycled polyester resin may be selected from the group consisting of recycled polyethylene terephthalate (r-PET), recycled polyethylene terephthalate glycol (r-PETG), recycled polyester sulfone (r-PES), recycled polybutylene terephthalate (r-PBT), recycled polytrimethylene terephthalate (r-PTT), recycled polybutylene adipate-co-terephthalate (r-PBAT), recycled polypropylene adipate-co-terephthalate (r-PPAT), recycled polycyclohexanedimethyl terephthalate (r-PCT), and recycled thermoplastic polyester elastomer (r-TPEE).

[0057]

[0058] Method for manufacturing recycled polyester resin

[0059] The present invention includes a method for manufacturing the above-mentioned recycled polyester resin. Accordingly, the specific types and contents of the recycled raw materials, recycled acid components, and recycled diol components described below are the same as those described above, so a detailed description is omitted.

[0060] The method for manufacturing a recycled polyester resin of the present invention comprises the step of polymerizing by reacting a polymerization raw material containing a recycled raw material, wherein the recycled raw material comprises one or more of a recycled diol component and a recycled acid component, wherein the content of an organic acid-containing compound measured by ion chromatography of the recycled diol component is 300 ppm or less, and the content of an organic acid-containing compound measured by ion chromatography of the recycled acid component is 5 ppm or less.

[0061] The recycled polyester resin of the present invention can be manufactured by undergoing a process of esterifying a polymerization raw material containing recycled raw material, or by subjecting it to a condensation polymerization reaction following an esterification exchange reaction. Specifically, the recycled polyester resin of the present invention can be obtained by undergoing a process of esterifying a polymerization raw material containing recycled raw material to produce an oligomer, and then subjecting it to a condensation polymerization reaction.

[0062] The above esterification 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.

[0063] The above polymerization raw material includes the aforementioned recycled raw material, thereby enabling the environmentally friendly production of high-quality recycled polyester resin. 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, and branching agents.

[0064] 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.

[0065] The above-mentioned colorants may include 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 toner, Clariant’s Solvaperm Red BB toner).

[0066] The above crystallizing agent may include a crystallization nucleating agent, a UV absorber, a polyolefin resin, a polyamide resin, etc.

[0067] The above antioxidants may include hindered phenolic compounds, phosphite compounds, thioether compounds, etc.

[0068] The above-mentioned branching agent may be trimellitic acid, trimellitic anhydride, trimethylol propane, or a combination thereof.

[0069] The temperature at which the above esterification reaction is performed may specifically be 210 to 300 ℃, 215 to 290 ℃, 220 to 280 ℃, 230 to 275 ℃, 235 to 270 ℃, or 240 to 265 ℃. In addition, the pressure at which the above esterification reaction is performed may specifically be 0.1 to 5 kgf / ㎠, 0.3 to 4 kgf / ㎠, 0.5 to 3.5 kgf / ㎠, 0.5 to 3 kgf / ㎠, or 1 to 2.5 kgf / ㎠. As the above esterification reaction is performed under the above conditions, an oligomer having a desired molecular weight can be obtained in high yield while minimizing the generation of by-products.

[0070] The above polycondensation reaction can be carried out by introducing a reactant containing the oligomer into a batch reactor or a continuous reactor and controlling the reaction temperature and / or reaction pressure.

[0071] Specifically, the temperature at which the above polycondensation reaction is performed may be 230 to 320 ℃, 240 to 310 ℃, 250 to 300 ℃, 255 to 295 ℃, or 260 to 290 ℃. In addition, the pressure at which the above polycondensation reaction is performed may be a pressure lower than atmospheric pressure (e.g., 1 atmosphere) (reduced pressure). As the above polycondensation reaction is performed under the above conditions, a recycled polyester resin having crystallinity and excellent processability can be obtained.

[0072] Meanwhile, the recycled polyester resin obtained through the above condensation reaction may undergo a solid-state polymerization reaction to control intrinsic viscosity (IV), molecular weight, etc. The conditions of the above solid-state polymerization reaction are not particularly limited and can be appropriately controlled according to the intrinsic viscosity, molecular weight, etc. of the desired recycled polyester resin.

[0073]

[0074] Article (molded product)

[0075] The articles of the present invention are manufactured from the recycled polyester resin described above. Specifically, the articles of the present invention may be obtained by molding the recycled polyester resin described above using molding methods such as extrusion, press fitting, injection molding, blow molding, or vacuum molding. For example, the articles of the present invention may be cosmetic containers, food containers, films (specifically, heat-shrink films, blown films, etc.), sheets, or profiles.

[0076] Since such articles are manufactured using the aforementioned recycled polyester resin, they may have excellent quality such as heat resistance and color. For example, when measuring transmittance on an injection molded specimen with a thickness of 6 mm, the articles may exhibit a transmittance of 80% or more, thus having excellent transparency. Specifically, the articles may have a transmittance of 81% or more, 83% or more, 85% or more, 86% or more, 87% or more, or 88% or more (e.g., 80 to 98%, 83 to 93%, or 85 to 90%).

[0077]

[0078] 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.

[0079]

[0080] [Example 1]

[0081] In a 10 L reactor connected to a column and a condenser capable of cooling by water, regenerated bis-2-hydroxyethyl terephthalate (r-BHET, 3136.7 g), regenerated terephthalic acid (r-TPA, 1230.0 g), regenerated ethylene glycol (r-EG, 883.6 g), regenerated 1,4-cyclohexanedimethanol (r-CHDM, 1067.0 g), regenerated isosorbide (r-ISB, 288.5 g), regenerated diethylene glycol (r-DEG, 52.4 g), terephthalic acid (TPA, 4100.0 g), bis-2-hydroxyethyl terephthalate (BHET, 1254.7 g), ethylene glycol (EG, 612.5 g), cyclohexanedimethanol (CHDM, 10.7 g), diethylene glycol (DEG, 52.4 g), Ti catalyst (0.4 g), phosphoric acid (10.0 g), blue toner (0.01 g), and red toner (0.005 g) were added. Next, the temperature of the reactor was raised to 260 ℃, and then an esterification reaction (ES) was carried out at a temperature of 260 ℃ under a pressure of 1 kgf / ㎠ to obtain a transparent reaction product.

[0082] Next, the above reactant was transferred to a polycondensation reactor, and a polycondensation reaction (PA) was carried out at 265 °C while maintaining the pressure of the polycondensation reactor at a level lower than atmospheric pressure. When the intrinsic viscosity (IV) of the reactant in the polycondensation reactor reached 0.7 dl / g, the reactant was discharged to the outside of the polycondensation reactor.

[0083] Next, the reactant discharged from the above-mentioned condensation reactor was introduced into a solid-state polymerization reactor, and the temperature of the solid-state polymerization reactor was gradually raised to 200°C under a nitrogen atmosphere, and then the solid-state polymerization reaction was carried out at 200°C. When the solid intrinsic viscosity (IV) of the reactant in the solid-state polymerization reactor reached 1.0 dl / g, the reactant was discharged from the solid-state polymerization reactor to produce a recycled polyester resin.

[0084]

[0085] [Example 2]

[0086] Regenerated bis-2-hydroxyethyl terephthalate (r-BHET, 1193.6 g), regenerated terephthalic acid (r-TPA, 2340.2 g), regenerated ethylene glycol (r-EG, 1452.9 g), regenerated diethylene glycol (r-DEG, 686.1 g), terephthalic acid (TPA, 4680.5 g), ethylene glycol (EG, 1748.1 g), 1,4-cyclohexanedimethanol (CHDM, 1353.4 g), isosorbide (ISB, 9.1 g), Ge catalyst (6.4 g), blue toner (0.03 g) and red toner (0.015 g) were introduced into a 10 L reactor connected to a column and a condenser capable of cooling by water. Next, the temperature of the reactor was raised to 260 ℃, and then an esterification reaction (ES) was carried out at a temperature of 260 ℃ under a pressure of 2 kgf / ㎠ to obtain a transparent reaction product.

[0087] Next, the above reactant was transferred to a polycondensation reactor, and a polycondensation reaction (PA) was carried out at 275 °C while maintaining the pressure of the polycondensation reactor at a level lower than atmospheric pressure. When the intrinsic viscosity (IV) of the reactant in the polycondensation reactor reached 0.65 dl / g, the reactant was discharged to the outside of the polycondensation reactor to produce a recycled polyester resin.

[0088]

[0089] [Example 3]

[0090] In a 10 L reactor connected to a column and a condenser coolable by water, regenerated terephthalic acid (r-TPA, 3955.2 g), regenerated ethylene glycol (r-EG, 3129.8 g), regenerated 1,4-cyclohexanedimethanol (r-CHDM, 960.7 g), regenerated diethylene glycol (r-DEG, 347.9 g), regenerated 1,4-cyclohexanedimethanol derivative (r-CHDM derivative, 347.9 g), terephthalic acid (TPA, 3955.2 g), ethylene glycol (EG, 886.4 g), isosorbide (ISB, 4.6 g), diethylene glycol (DEG, 252.6 g), 1,4-cyclohexanedimethanol derivative (CHDM derivative, 347.9 g), Ge catalyst (6.4 g), Ti catalyst (0.5 g), blue Toner (0.04 g) and red toner (0.01 g) were added. Next, the temperature of the reactor was raised to 260 ℃, and then an esterification reaction (ES) was carried out at a temperature of 260 ℃ under a pressure of 0.5 kgf / ㎠ to obtain a transparent reaction product.

[0091] Next, the above reactant was transferred to a polycondensation reactor, and a polycondensation reaction (PA) was carried out at 275 °C while maintaining the pressure of the polycondensation reactor at a level lower than atmospheric pressure. When the intrinsic viscosity (IV) of the reactant in the polycondensation reactor reached 0.75 dl / g, the reactant was discharged to the outside of the polycondensation reactor to produce a recycled polyester resin.

[0092]

[0093] [Example 4]

[0094] Regenerated terephthalic acid (r-TPA, 2902.1 g), regenerated ethylene glycol (r-EG, 408.3 g), regenerated 1,4-cyclohexanedimethanol (r-CHDM, 4594.4 g), regenerated isosorbide (r-ISB, 1701.6 g), terephthalic acid (TPA, 2902.1 g), bis-2-hydroxyethyl terephthalate (BHET, 2220.3 g), 1,4-cyclohexanedimethanol (CHDM, 16.8 g), diethylene glycol (DEG, 231.6 g), Ti catalyst (0.4 g), phosphoric acid (3.0 g), blue toner (0.015 g) and red toner (0.005 g) were introduced into a 10 L reactor connected to a column and a condenser capable of cooling by water. Next, the temperature of the reactor was raised to 265 ℃, and an esterification reaction (ES) was carried out at a temperature of 265 ℃ under a pressure of 1 kgf / ㎠ to obtain a transparent reaction product.

[0095] Next, the above reactant was transferred to a polycondensation reactor, and a polycondensation reaction (PA) was carried out at 280°C while maintaining the pressure of the polycondensation reactor at a level lower than atmospheric pressure. When the intrinsic viscosity (IV) of the reactant in the polycondensation reactor reached 0.75 dl / g, the reactant was discharged to the outside of the polycondensation reactor to produce a recycled polyester resin.

[0096]

[0097] [Example 5]

[0098] Regenerated bis-2-hydroxyethyl terephthalate (r-BHET, 2369.8 g), regenerated ethylene glycol (r-EG, 1156.9 g), regenerated 1,4-cyclohexanedimethanol derivative (r-CHDM derivative, 204.3 g), terephthalic acid (TPA, 6195.1 g), ethylene glycol (EG, 1706.4 g), 1,4-cyclohexanedimethanol (CHDM, 1679.4 g), 1,4-cyclohexanedimethanol derivative (CHDM, 204.3 g), Ge catalyst (12.8 g), Ti catalyst (0.9 g), blue toner (0.006 g) and red toner (0.002 g) were introduced into a 10 L reactor connected to a column and a condenser capable of cooling by water. Next, the temperature of the reactor was raised to 255 ℃, and an esterification reaction (ES) was carried out at a temperature of 255 ℃ under a pressure of 2 kgf / ㎠ to obtain a transparent reaction product.

[0099] Next, the above reactant was transferred to a polycondensation reactor, and a polycondensation reaction (PA) was carried out at 285 °C while maintaining the pressure of the polycondensation reactor at a level lower than atmospheric pressure. When the intrinsic viscosity (IV) of the reactant in the polycondensation reactor reached 0.8 dl / g, the reactant was discharged to the outside of the polycondensation reactor to produce a recycled polyester resin.

[0100]

[0101] [Example 6]

[0102] Regenerated bis-2-hydroxyethyl terephthalate (r-BHET, 5627.4 g), regenerated terephthalic acid (r-TPA, 2942.2 g), regenerated 1,4-cyclohexanedimethanol (r-CHDM, 2552.3 g), terephthalic acid (TPA, 735.6 g), ethylene glycol (EG, 549.5 g), Ge catalyst (12.8 g), Ti catalyst (0.9 g), blue toner (0.006 g), and red toner (0.002 g) were introduced into a 10 L reactor connected to a column and a condenser capable of cooling by water. Next, the temperature of the reactor was raised to 255 ℃, and an esterification reaction (ES) was carried out at a temperature of 255 ℃ under a pressure of 2 kgf / ㎠ to obtain a transparent reaction product.

[0103] Next, the above reactant was transferred to a polycondensation reactor, and a polycondensation reaction (PA) was carried out at 285 °C while maintaining the pressure of the polycondensation reactor at a level lower than atmospheric pressure. When the intrinsic viscosity (IV) of the reactant in the polycondensation reactor reached 0.8 dl / g, the reactant was discharged to the outside of the polycondensation reactor to produce a recycled polyester resin.

[0104]

[0105] [Example 7]

[0106] Regenerated bis-2-hydroxyethyl terephthalate (r-BHET, 3711.6 g), regenerated ethylene glycol (r-EG, 402.7 g), regenerated isosorbide (r-ISB, 474.1 g), terephthalic acid (TPA, 5660.0 g), isophthalic acid (IPA, 8085.7 g), ethylene glycol (EG, 2114.0 g), 1,4-cyclohexanedimethanol (CHDM, 1402.8 g), diethylene glycol (DEG, 258.2 g), Ti catalyst (0.9 g), phosphoric acid (1.0 g), blue toner (0.02 g) and red toner (0.01 g) were added to a 10 L reactor connected to a column and a condenser capable of cooling by water. Next, the temperature of the reactor was raised to 260 ℃, and then an esterification reaction (ES) was carried out at a temperature of 260 ℃ under a pressure of 3 kgf / ㎠ to obtain a transparent reaction product.

[0107] Next, the above reactant was transferred to a polycondensation reactor, and a polycondensation reaction (PA) was carried out at 275 °C while maintaining the pressure of the polycondensation reactor at a level lower than atmospheric pressure. When the intrinsic viscosity (IV) of the reactant in the polycondensation reactor reached 0.65 dl / g, the reactant was discharged to the outside of the polycondensation reactor to produce a recycled polyester resin.

[0108]

[0109] [Example 8]

[0110] Regenerated terephthalic acid (r-TPA, 5087.3 g), terephthalic acid (TPA, 3391.6 g), ethylene glycol (EG, 3800.2 g), 1,4-cyclohexanedimethanol (CHDM, 735.5 g), diethylene glycol (DEG, 270.7 g), Ti catalyst (0.9 g), Ge catalyst (25.6 g), blue toner (0.04 g), and red toner (0.01 g) were introduced into a 10 L reactor connected to a column and a condenser capable of cooling by water. Next, the temperature of the reactor was raised to 270 ℃, and an esterification reaction (ES) was carried out at a temperature of 270 ℃ under a pressure of 2 kgf / ㎠ to obtain a transparent reaction product.

[0111] Next, the above reactant was transferred to a polycondensation reactor, and a polycondensation reaction (PA) was carried out at 275 °C while maintaining the pressure of the polycondensation reactor at a level lower than atmospheric pressure. When the intrinsic viscosity (IV) of the reactant in the polycondensation reactor reached 0.60 dl / g, the reactant was discharged to the outside of the polycondensation reactor to produce a recycled polyester resin.

[0112]

[0113] [Comparative Example 1]

[0114] Terephthalic acid (TPA, 4204.2 g), bis-2-hydroxyethyl terephthalate (BHET, 6433.0 g), ethylene glycol (EG, 942.2 g), 1,4-cyclohexanedimethanol (CHDM, 1458.8 g), Ge catalyst (12.8 g), blue toner (0.02 g), and red toner (0.01 g) were introduced into a 10 L reactor connected to a column and a condenser capable of cooling by water. Next, the temperature of the reactor was raised to 260 ℃, and an esterification reaction (ES) was carried out at 260 ℃ under a pressure of 0.5 kgf / ㎠ to obtain a transparent reaction product.

[0115] Next, the above reactant was transferred to a polycondensation reactor, and a polycondensation reaction (PA) was carried out at 280°C while maintaining the pressure of the polycondensation reactor at a level lower than atmospheric pressure. When the intrinsic viscosity (IV) of the reactant in the polycondensation reactor reached 0.7 dl / g, the reactant was discharged to the outside of the polycondensation reactor to produce a polyester resin.

[0116]

[0117] [Comparative Example 2]

[0118] In a 10 L reactor connected to a column and a condenser capable of cooling by water, regenerated bis-2-hydroxyethyl terephthalate (r-BHET, 1254.7 g), regenerated terephthalic acid (r-TPA, 410.0 g), regenerated ethylene glycol (r-EG, 3184.7 g), regenerated 1,4-cyclohexanedimethanol (r-CHDM, 711.3 g), regenerated isosorbide (r-ISB, 288.5 g), regenerated diethylene glycol (r-DEG, 72.1 g), terephthalic acid (TPA, 6150.0 g), ethylene glycol (EG, 153.1 g), cyclohexanedimethanol (CHDM, 355.7 g), isosorbide (ISB, 1.0 g), diethylene glycol (DEG, 52.4 g), Ti catalyst (0.4 g), and blue Toner (0.015 g) and red toner (0.005 g) were added. Next, the temperature of the reactor was raised to 265 ℃, and then an esterification reaction (ES) was carried out at a temperature of 265 ℃ under a pressure of 1 kgf / ㎠ to obtain a transparent reaction product.

[0119] Next, the above reactant was transferred to a polycondensation reactor, and a polycondensation reaction (PA) was carried out at 270 °C while maintaining the pressure of the polycondensation reactor at a level lower than atmospheric pressure. When the intrinsic viscosity (IV) of the reactant in the polycondensation reactor reached 0.7 dl / g, the reactant was discharged to the outside of the polycondensation reactor.

[0120] Next, the reactant discharged from the above-mentioned condensation reactor was introduced into a solid-state polymerization reactor, and the temperature of the solid-state polymerization reactor was gradually raised to 200°C under a nitrogen atmosphere, and then the solid-state polymerization reaction was carried out at 200°C. When the solid intrinsic viscosity (IV) of the reactant in the solid-state polymerization reactor reached 0.9 dl / g, the reactant was discharged from the solid-state polymerization reactor to produce a recycled polyester resin.

[0121]

[0122] [Comparative Example 3]

[0123] Regenerated terephthalic acid (r-TPA, 1838.9 g), regenerated ethylene glycol (EG, 3186.8 g), regenerated 1,4-cyclohexanedimethanol (r-CHDM, 4657.9 g), terephthalic acid (TPA, 5516.7 g), ethylene glycol (EG, 137.4 g), 1,4-cyclohexanedimethanol (CHDM, 319.0 g), diethylene glycol (DEG, 47 g), Ge catalyst (12.8 g), Ti catalyst (0.9 g), blue toner (0.006 g) and red toner (0.002 g) were introduced into a 10 L reactor connected to a column and a condenser capable of cooling by water. Next, the temperature of the reactor was raised to 265 ℃, and an esterification reaction (ES) was carried out at a temperature of 265 ℃ under a pressure of 1 kgf / ㎠ to obtain a transparent reaction product.

[0124] Next, the above reactant was transferred to a polycondensation reactor, and a polycondensation reaction (PA) was carried out at 270°C while maintaining the pressure of the polycondensation reactor at a level lower than atmospheric pressure. When the intrinsic viscosity (IV) of the reactant in the polycondensation reactor reached 0.8 dl / g, the reactant was discharged to the outside of the polycondensation reactor to produce a recycled polyester resin.

[0125]

[0126] [Test Example 1]

[0127] The purity of each of the regenerated diol component and regenerated acid component used in the above examples and comparative examples was confirmed by analyzing them using commonly known high-performance liquid chromatography (HPLC) (Waters Acquity HPLC) and gas chromatography (GC) (Agilent 7890B). In addition, based on the input amount and molecular weight of each regenerated monomer used as the regenerated diol component and regenerated acid component, the content of repeating unit A derived from the regenerated raw material (regenerated diol component + regenerated acid component) was calculated.

[0128]

[0129] [Test Example 2]

[0130] The content of organic acid-containing compounds (specifically, formate) contained in each of the regenerated diol components and regenerated acid components used in the above examples and comparative examples was confirmed by analyzing them using commonly known ion chromatography (Thermo, ICS-5000).

[0131]

[0132] [Test Example 3]

[0133] The amount of CO2 generated (emission) during the process of manufacturing 1 kg of the polyester resin of the above examples and comparative examples was verified through a Life Cycle Assessment according to ISO 14000, and the CO2 reduction ratio was calculated by comparing it with the amount of CO2 generated (emission) during the process of manufacturing 1 kg of virgin polyester resin of the same composition.

[0134]

[0135] [Test Example 4]

[0136] After drying the polyester resins of each of the above examples and comparative examples, they were fed into the hopper of an injection molding press (ENGEL 80). Subsequently, injection molding was performed at an injection temperature of 230 to 270 °C and a mold temperature of 30 °C to produce injection specimens with a thickness of 6 mm, and then the transmittance of the produced injection specimens was measured according to ASTM D1003.

[0137]

[0138] The results of the above test examples are shown in Tables 1 and 2 below.

[0139]

[0140] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Repeating Unit A (Recycled Raw Material) Content (wt%) 483 765 751 895 2732 HPLC (Area%) r-BHET 98.2 198.1--96.2 197.2 298.21-GC Purity (Area%) r-EG 99.8 99.6 99.2 99.2 99.6 -99.9 - r-CHDM / r-CHDM derivative 99 -9999.8 99.8 99.8 - r-DEG 99.5 999.9 8 99.8 3 ----- r-ISB 99.8 -99.9 -99.5 - r-TPA 9999.8 99.5 99 -99.5 -95 Formate content (ppm) Regenerated diol component 6 29 1 16 9 1 13 6 9 8 5 50 Regenerated acid component 2 3.6 5 4.5 0.8 4 1.45 CO2 reduction ratio (%) 16.0 9.0 18.8 3 1.1 16.7 3 7.3 9.55 Transmittance (%) 90 8 38 28 08 99 08 781

[0141] Comparative Example 1 Comparative Example 2 Comparative Example 3 Repeating Unit A (Recycled Raw Material) Content (wt%) 0.408 1HPLC (Area%) r-BHET-91.2-GC Purity (Area%) r-EG-97.3 98.9 r-CHDM-99.8 90 r-DEG-98.5 r-ISB-97 r-TPA-97 94Formate Content (ppm) Recycled Diol Component-335 419 Recycled Acid Component-6.0 12.3 CO2 Reduction Ratio (%) 0.0 3.2 27 Transmittance (%) 837 975

[0142] Referring to Tables 1 and 2 above, the recycled polyester resins of Examples 1 to 8 according to the present invention are manufactured using recycled diol components and / or recycled acid components in which the content of organic acid-containing compounds is controlled within the range intended by the present invention, so a carbon reduction effect can be achieved with a high CO2 reduction ratio (%). Furthermore, it can be confirmed that injection-molded specimens produced from the recycled polyester resins have high transmittance and excellent transparency. In particular, it can be seen that it is possible to provide articles of superior quality with a significantly higher CO2 reduction ratio (%) than the polyester resin of Comparative Example 1, which corresponds to virgin polyester resin.

[0143] In addition, as the content of organic acid-containing compounds is controlled within the range intended by the present invention, it can be confirmed that the purity of each of the regenerated diol component and the regenerated acid component is high (for example, regarding the regenerated raw materials used in the examples, it was confirmed through HPCL and GC analysis results that the purity of r-BHET is 95% or higher; the purity of each of r-EG, r-CHDM, r-DEG, and r-ISB is 99% or higher; and the purity of r-TPA is 95% or higher).

Claims

1. Includes repeating unit A derived from recycled materials, and The above-mentioned regenerated raw material includes one or more of a regenerated diol component and a regenerated acid component, and The above-mentioned regenerated diol component has an organic acid-containing compound content of 300 ppm or less as measured by ion chromatography, and The above-mentioned regenerated acid component is a regenerated polyester resin having an organic acid-containing compound content of 5 ppm or less as measured by ion chromatography.

2. In Paragraph 1, The above-mentioned regenerated raw material includes the above-mentioned regenerated diol component and the above-mentioned regenerated acid component, and The above repeating unit A comprises a repeating unit A-1 derived from the above-mentioned regenerated diol component and a repeating unit A-2 derived from the above-mentioned regenerated acid component, wherein the above-mentioned repeating unit A comprises a repeating unit A-1 derived from the above-mentioned regenerated diol component and a repeating unit A-2 derived from the above-mentioned regenerated acid component, a regenerated polyester resin.

3. In Paragraph 1, A recycled polyester resin having a content of repeating unit A derived from the above recycled raw material of 15% by weight or more based on the total weight of the recycled polyester resin.

4. In Paragraph 1, Recycled polyester resin having a CO2 reduction ratio of 5% or more compared to virgin polyester resin when CO2 emissions are evaluated per 1 kg of production volume through Life Cycle Assessment according to ISO 14000.

5. In Paragraph 1, The above-mentioned regenerated diol component comprises one or more selected from the group consisting of regenerated ethylene glycol, regenerated cyclohexanedimethanol, regenerated cyclohexanedimethanol derivatives, regenerated neopentyl glycol, regenerated isosorbide, regenerated diethylene glycol, and regenerated bis-2-hydroxyethyl terephthalate, a regenerated polyester resin.

6. In Paragraph 1, The above-mentioned recycled acid component comprises one or more selected from the group consisting of recycled terephthalic acid, recycled isophthalic acid, recycled dimethyl phthalate, and recycled dimethyl terephthalate, a recycled polyester resin.

7. In Paragraph 1, It further includes repeating unit B derived from virgin raw materials, and The above virgin raw material is a recycled polyester resin containing one or more of a diol component and an acid component.

8. In Paragraph 7, A recycled polyester resin comprising one or more types selected from the group consisting of the above diol components: ethylene glycol, cyclohexanedimethanol, cyclohexanedimethanol derivatives, neopentyl glycol, isosorbide, diethylene glycol, bis-2-hydroxyethyl terephthalate, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, 2-methylene-1,3-propanediol, 2-ethyl-1,3-propanediol, 2-isopropyl-1,3-propanediol, 1,4-butanediol, 2,3-butanediol, 3-methyl-1,5-pentanediol, 3-methyl-2,4-pentanediol, 1,6-hexanediol, 1,2-cyclohexanediol, and 1,4-cyclohexanediol.

9. In Paragraph 7, A recycled polyester resin comprising one or more acid components selected from the group consisting of terephthalic acid, isophthalic acid, dimethyl isophthalate, dimethyl phthalate, dimethyl terephthalate, phthalic acid, phthalic anhydride, 2,6-naphthalene dicarboxylic acid, dimethyl 2,6-naphthalene dicarboxylate, diphenyl dicarboxylic acid, 1,4-cyclohexane dicarboxylic acid, 1,3-cyclohexane dicarboxylic acid, dimethyl 1,4-cyclohexane dicarboxylate, dimethyl 1,3-cyclohexane dicarboxylate, sebacic acid, succinic acid, isodecylic succinic acid, maleic acid, maleic anhydride, fumaric acid, adipic acid, glutaric acid, and azelaic acid.

10. In Paragraph 1, Recycled polyester resin having an intrinsic viscosity of 0.5 to 1.2 dl / g.

11. In Paragraph 1, Recycled polyester resin that exhibits a transmittance of 80% or more when injection molded to a thickness of 6 mm and measured.

12. An article manufactured from recycled polyester resin according to any one of claims 1 to 11.

13. In Paragraph 12, Articles that are cosmetic containers, food containers, films, sheets, or profiles.

14. A step of polymerizing by reacting a polymerization raw material containing a recycled raw material, and The above-mentioned regenerated raw material includes one or more of a regenerated diol component and a regenerated acid component, and The above-mentioned regenerated diol component has an organic acid-containing compound content of 300 ppm or less as measured by ion chromatography, and A method for manufacturing a recycled polyester resin in which the above-mentioned recycled acid component has an organic acid-containing compound content of 5 ppm or less as measured by ion chromatography.