Plasticizer composition and resin composition including the same

Abstract

This invention relates to a plasticizer composition comprising 2-ethylhexyl (2-hydroxyethyl) p-phthalate, di(2-ethylhexyl) isophthalate, and di(2-ethylhexyl) p-phthalate, wherein the content of 2-ethylhexyl (2-hydroxyethyl) p-phthalate is 20 wt% or less based on the total plasticizer composition, and that when the plasticizer composition is applied to resin, it can improve mechanical properties, anti-migration properties, and volatile loss properties.

Description

Technical Field

[0001] The present invention relates to a plasticizer composition comprising 2-ethylhexyl (2-hydroxyethyl) terephthalate, di(2-ethylhexyl) isophthalate, and di(2-ethylhexyl) terephthalate, and a resin composition comprising the plasticizer composition. [Cross-reference to related applications] []

[0002] This case claims the benefit of Korean Patent Application No. 10-2022-0024953, filed on February 25, 2022, with the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety. Prior Art

[0003] Typically, in plasticizers, alcohols react with polycarboxylic acids, such as phthalic acid and adipic acid, to form corresponding esters. Furthermore, in light of domestic and international regulations regarding the harmful effects of phthalate-based plasticizers on the human body, research is ongoing into alternative plasticizer compositions to phthalate-based plasticizers, such as terephthalate-based, adipate-based, and other polymer-based plasticizers.

[0004] Furthermore, in the plastisol and car-rendering industries, as well as in the extrusion / injection compounding industries used to manufacture finished products such as flooring, wallpaper, soft and hard sheets, gloves, wire, hoses, and films, there is a growing demand for these environmentally friendly products. To enhance the quality, processability, and productivity of each finished product, appropriate plasticizers must be used with considerations such as discoloration, migration, and mechanical properties.

[0005] In these various application areas, auxiliary raw materials such as plasticizers, fillers, stabilizers, viscosity reducers, dispersants, defoamers, and foaming agents are mixed into PVC resin according to the properties required by each industry, such as tensile strength, elongation, light resistance, migration, gelling, or absorption rate.

[0006] For example, among plasticizer compositions that can be applied to PVC, when di(2-ethylhexyl) terephthalate (DEHTP), which is relatively cheap and the most commonly used, is used, the hardness or sol viscosity is high, the plasticizer absorption rate is slow, and migration and stress degradation are poor.

[0007] To improve this, DEHTP-containing compositions can consider using products of transesterification reactions (with butanol) as plasticizers. However, while this improves plasticization efficiency, mechanical properties are slightly reduced, and there is a unique problem of plasticizer leakage due to heat or physical forces.

[0008] Furthermore, ensuring environmental protection has become increasingly important in recent times. This is not just about ensuring the environmental protection of the final product itself, but also about ensuring the environmental protection of the supply and demand of raw materials and the manufacturing process. However, this conflicts with the industry's primary task of ensuring cost competitiveness. Consequently, there is a need to develop products that are environmentally friendly in terms of raw materials, manufacturing processes, and final products, while also being cost-competitive. Summary of the Invention

[0009] [Technical Issues] []

[0010] The present invention provides an environmentally friendly plasticizer composition that is non-toxic to reproductive development and has performance equivalent to or superior to that of typical phthalate plasticizers by applying a composition comprising 2-ethylhexyl (2-hydroxyethyl) terephthalate, di(2-ethylhexyl) isophthalate, and di(2-ethylhexyl) terephthalate (obtained during the decomposition process of polyethylene terephthalate) to a plasticizer.

[0011] Furthermore, the present invention provides a method for preparing a plasticizer composition, which can economically and environmentally prepare a plasticizer composition having excellent physical properties by using discarded polyethylene terephthalate as a raw material. [Technical solution] [] []

[0012] In order to solve the above problems, the present invention provides a plasticizer composition, a method for preparing the same, and a resin composition containing the plasticizer composition.

[0013] (1) The present invention provides a plasticizer composition comprising 2-ethylhexyl (2-hydroxyethyl) terephthalate, di(2-ethylhexyl) isophthalate, and di(2-ethylhexyl) terephthalate, wherein the content of 2-ethylhexyl (2-hydroxyethyl) terephthalate is 20 wt% or less based on the total plasticizer composition.

[0014] (2) In the above (1), the present invention provides a plasticizer composition, wherein the content of 2-ethylhexyl (2-hydroxyethyl) terephthalate is 0.01 wt% to 15 wt%.

[0015] (3) In the above (1) or (2), the present invention provides a plasticizer composition, wherein the weight ratio between 2-ethylhexyl (2-hydroxyethyl) terephthalate and di(2-ethylhexyl) terephthalate is 1:3 to 1:10000.

[0016] (4) In any one of the above (1) to (3), the present invention provides a plasticizer composition, wherein the weight ratio between 2-ethylhexyl (2-hydroxyethyl) terephthalate and di(2-ethylhexyl) terephthalate is 1:5 to 1:1000.

[0017] (5) In any one of the above (1) to (4), the present invention provides a plasticizer composition further comprising a condensate of bis(2-hydroxyethyl) terephthalate and 2-ethylhexyl(2-hydroxyethyl) terephthalate.

[0018] (6) In any one of the above (1) to (5), the present invention provides a plasticizer composition further comprising any one or more dimer compounds represented by the following formulas 1 to 3.

[0019] [Formula 1]

[0020] [Formula 2]

[0021] [Formula 3]

[0022] (7) In the above (6), the present invention provides a plasticizer composition, wherein the total content of the dimer compound in the composition is 2.0 wt% to 20.0 wt%.

[0023] (8) In the above (6) or (7), the present invention provides a plasticizer composition, wherein the content of the dimer compound represented by the above formula 1 in the composition is 0.01 wt% to 1 wt%.

[0024] (9) In any one of the above (6) to (8), the present invention provides a plasticizer composition, wherein the content of the dimer compound represented by the above formula 3 in the composition is 0.3 wt% to 2.5 wt%.

[0025] (10) In any one of the above (6) to (9), the present invention provides a plasticizer composition, wherein the weight ratio between the dimer compound and 2-ethylhexyl (2-hydroxyethyl) terephthalate in the composition is 1:0.001 to 5.

[0026] (11) In any one of the above (6) to (10), the present invention provides a plasticizer composition, wherein the weight ratio between the dimer compound and di(2-ethylhexyl) terephthalate in the composition is 1:2.0 to 99.0.

[0027] (12) The present invention provides a method for preparing a plasticizer composition, wherein the method comprises mixing polyethylene terephthalate and 2-ethylhexanol in the presence of a catalyst to carry out an esterification reaction, wherein the product of the esterification reaction comprises 2-ethylhexyl (2-hydroxyethyl) terephthalate, di(2-ethylhexyl) isophthalate, and di(2-ethylhexyl) terephthalate.

[0028] (13) In the above (12), the present invention provides a method for preparing a plasticizer composition, wherein polyethylene terephthalate is mixed in an amount of 80 wt% or less relative to the total content of polyethylene terephthalate and 2-ethylhexanol.

[0029] (14) In the above (12) or (13), the present invention provides a method for preparing a plasticizer composition, wherein the polyethylene terephthalate comprises discarded and recycled polyethylene terephthalate.

[0030] (15) The present invention provides a resin composition comprising 100 parts by weight of a resin and 5 to 150 parts by weight of a plasticizer composition as claimed in claim 1, wherein the resin is one or more selected from the group consisting of a straight vinyl chloride polymer, a paste vinyl chloride polymer, an ethylene vinyl acetate copolymer, an ethylene polymer, a propylene polymer, a polyketone, a polystyrene, a polyurethane, a polylactic acid, a natural rubber, and a synthetic rubber. [Beneficial effects] []

[0031] The plasticizer composition according to one embodiment of the present invention is an environmentally friendly material that is non-toxic to reproductive development. When used in a resin composition, it can improve mechanical properties, migration resistance, stress migration, and absorption rate (compared to typical plasticizers). Furthermore, the top-down preparation method utilizes waste, making it an environmentally friendly preparation method and highly cost-competitive. [] Implementation Method

[0032] It is understood that the words and terms used in the specification and claims of the present invention should not be construed as limited to the meanings defined in commonly used dictionaries. Based on the principle that the inventors can appropriately define the meanings of words and terms to best explain the present invention, it is further understood that such words and terms should be interpreted as having meanings consistent with their meanings in the relevant technical content and the technical concepts of the present invention.

[0033] [Definition of terms]

[0034] The term "composition" as used herein includes not only reaction products and decomposition products formed from the materials of the corresponding composition, but also a mixture including the materials of the corresponding composition.

[0035] As used herein, "straight vinyl chloride polymer" refers to a type of vinyl chloride polymer that is polymerized through suspension polymerization, bulk polymerization, or the like. The polymer is a porous particle with numerous pores, ranging in size from tens to hundreds of microns, exhibits no cohesiveness, and exhibits excellent flowability.

[0036] As used herein, "paste vinyl chloride polymer" refers to a type of vinyl chloride polymer produced through micro-suspension polymerization, micro-seed polymerization, or emulsion polymerization. The polymer is a fine, dense, non-porous particle with a size ranging from tens to thousands of nanometers, exhibits cohesive properties, and exhibits poor flow properties.

[0037] The terms "comprising," "having," and their derivatives, whether or not explicitly disclosed, are not intended to exclude the presence of any additional components, steps, or procedures. To avoid any uncertainty, all compositions claimed using the term "comprising" may include any additional additives, supplements, or compounds (whether polymeric or otherwise) unless otherwise stated. Conversely, the term "consisting essentially of" excludes any other component, step, or procedure from the scope of any subsequent description unless it is not essential for operability. The term "consisting of" excludes any component, step, or procedure not explicitly stated or listed.

[0038] [Measurement method]

[0039] In this specification, the content analysis of components in the composition was performed by gas chromatography measurement, and the analysis was performed using an Agilent gas chromatograph (product name: Agilent 7890 GC, column: HP-5, carrier gas: helium (flow rate: 2.4 mL / min), detector: FID, injection volume: 1 uL, initial value: 70°C / 4.2 min, end value: 280°C / 7.8 min, program rate: 15°C / min).

[0040] In this specification, "tensile strength" is calculated by the following equation 1 after measuring the breaking point of a specimen after pulling it (1T) at a cross head speed of 200 mm / min using a test apparatus UTM (manufacturer: Instron, model: 4466) according to the ASTM D638 method.

[0041] [Equation 1] Tensile strength (kgf / cm²) = load value (kgf) / thickness (cm) × width (cm)

[0042] In this specification, “elongation rate” is calculated by the following Equation 2 after measuring the breaking point of a specimen after stretching the specimen (1T) using UTM at a crosshead speed of 200 mm / min according to the ASTM D638 method.

[0043] [Equation 2] Elongation (%) = length after elongation / initial length × 100

[0044] In this specification, "migration loss" can be measured according to KSM-3156. Specifically, a test piece with a thickness of 1 mm is prepared, and an absorption sheet is attached to each side of the test piece, which absorbs organic material discharged onto the surface of the test piece. A plate that covers the entire test piece is then attached to the test piece, applying a load of 1 kgf / cm². The test piece is placed in a hot-air circulation oven (80°C) for 72 hours, then removed from the oven and cooled at room temperature for 4 hours. The plate and the absorption sheet attached to each side of the test piece are then removed. The weight of the sample before and after the sample is placed in the oven is measured to calculate the migration loss using the following equation 3.

[0045] [Equation 3] Migration loss (%) = {[(initial sample weight) - (sample weight after standing in the oven)] / (initial sample weight)} × 100

[0046] In this specification, "volatile loss" is obtained by treating a sample at 80° C. for 72 hours and then measuring the weight of the sample.

[0047] [Equation 4] Volatile loss (%) = {[(initial sample weight) - (sample weight after treatment)] / initial sample weight)} × 100

[0048] In the case of the various measurement conditions above, the detailed conditions such as temperature, rotation speed, time, etc. may be slightly different depending on the situation, and when the detailed conditions are different, the measurement method and its conditions are specified separately.

[0049] In this specification, the "absorption rate" is evaluated by measuring the time taken for a resin and a plasticizer to be mixed with each other using a planetary mixer (Brabender, P600) under the conditions of 77° C. and 60 rpm until the torque of the mixer stabilizes.

[0050] In the case of the various measurement conditions above, the detailed conditions such as temperature, rotation speed, time, etc. may be slightly different depending on the situation, and when the detailed conditions are different, the measurement method and its conditions are specified separately.

[0051] The present invention will be described in more detail below to facilitate understanding of the present invention.

[0052] [Plasticizer composition] [] []

[0053] The present invention provides a plasticizer composition comprising 2-ethylhexyl (2-hydroxyethyl) terephthalate, di(2-ethylhexyl) isophthalate, and di(2-ethylhexyl) terephthalate, wherein the content of 2-ethylhexyl (2-hydroxyethyl) terephthalate is 20 wt% or less based on the total plasticizer composition.

[0054] The plasticizer composition comprising 2-ethylhexyl (2-hydroxyethyl) terephthalate, di(2-ethylhexyl) isophthalate, and di(2-ethylhexyl) terephthalate can be obtained from a product produced by an esterification reaction between polyethylene terephthalate (hereinafter referred to as PET) and 2-ethylhexanol.

[0055] Typically, bis(2-ethylhexyl) terephthalate, a typical general-purpose plasticizer, is obtained by reacting PET with 2-ethylhexanol. However, this method generates a large amount of byproducts and is difficult to separate from bis(2-hydroxyethyl) terephthalate or 2-ethylhexyl(2-hydroxyethyl) terephthalate produced during the reaction process. Furthermore, bis(2-hydroxyethyl) terephthalate and 2-ethylhexyl(2-hydroxyethyl) terephthalate are alcohol-based compounds containing hydroxyl groups within their molecular structures, leading to the potential for side reactions with the target product, di(2-ethylhexyl) terephthalate. Therefore, as a method for producing di(2-ethylhexyl) terephthalate, almost every manufacturer uses a direct esterification reaction of terephthalic acid and 2-ethylhexanol or a transesterification reaction of dimethyl terephthalate and 2-ethylhexanol, rather than a method using PET as a raw material.

[0056] However, the present invention has determined that by focusing on the function of 2-ethylhexyl (2-hydroxyethyl) terephthalate, typically considered an impurity and therefore a target for removal, and allowing the inclusion of a predetermined amount of 2-ethylhexyl (2-hydroxyethyl) terephthalate in the plasticizer composition rather than its removal, a plasticizer composition with improved performance compared to typical plasticizer products can be provided. 2-ethylhexyl (2-hydroxyethyl) terephthalate is difficult to separate from di(2-ethylhexyl) terephthalate, but it can be used to address the compression migration problem of di(2-ethylhexyl) terephthalate, i.e., the expulsion of the plasticizer due to heat or pressure. Specifically, due to the presence of hydroxyl groups in its molecular structure, 2-ethylhexyl (2-hydroxyethyl) terephthalate can more firmly bond to the resin being mixed and can play a role in retaining di(2-ethylhexyl) terephthalate, the main component of the plasticizer composition, from being expelled from the resin.

[0057] According to one embodiment of the present invention, the content of 2-ethylhexyl (2-hydroxyethyl) terephthalate may be 20 wt% or less based on the total plasticizer composition. For example, the content of 2-ethylhexyl (2-hydroxyethyl) terephthalate, based on the total plasticizer composition, may be 0.01 wt % or more, 0.05 wt % or more, 0.06 wt % or more, 0.08 wt % or more, 0.10 wt % or more, 0.50 wt % or more, 1.0 wt % or more, 2.0 wt % or more, 3.0 wt % or more, 4.0 wt % or more, 4.5 wt % or more, 4.9 wt % or more, 5.0 wt % or more, 5.5 wt % or more, 7.5 wt % or more, 8.0 wt % or more, 20.0 wt % or less, 19.5 wt % or less, 19.0 wt % or less, 18.0 wt % or less, 17.0 wt % or less, 16.0 wt % or less, 15.0 wt % or less, 14.9 % or less, 14.5 wt % or less, 13.0 wt % or less, 12.8 wt % or less, 12.5 wt % or less, 12.4 wt % or less, 12.0 wt % or less, 11.7 wt % or less, 11.5 wt % or less, 11.3 wt % or less, 11.0 wt % or less, 10.5 wt % or less, 10.0 wt % or less, 9.5 wt % or less, 9.3 wt % or less, 8.0 wt % or less, 8.5 wt % or less, 8.0 wt % or less, 7.5 wt % or less, 7.2 wt % or less, 7.0 wt % or less, 6.5 wt % or less, 6.0 wt % or less, 5.5 wt % or less, 5.0 wt % or less, 4.5 wt % or less, 4.0 wt% or less, 3.5 wt% or less, 3.0 wt% or less, 2.5 wt% or less, or 2.0 wt% or less. Preferably, the terephthalate content, based on the total plasticizer composition, can be 0.01 wt% to 15 wt%. Furthermore, the weight ratio of 2-ethylhexyl (2-hydroxyethyl) terephthalate to di(2-ethylhexyl) terephthalate can be 1:3 to 10,000, preferably 1:5 to 1:2,000, or 1:5 to 1:1,000.When the content of 2-ethylhexyl (2-hydroxyethyl) terephthalate in the plasticizer composition is too low, the effect of improving the migration resistance of 2-ethylhexyl (2-hydroxyethyl) terephthalate is not significant. Conversely, when the content of 2-ethylhexyl (2-hydroxyethyl) terephthalate is too high, the content of di(2-ethylhexyl) terephthalate becomes relatively small, resulting in poor volatile loss and excessively increased absorption rate. This leads to unstable process conditions for blending with resin and manufacturing of finished products, thereby deteriorating the overall heat resistance of the resin composition or the finished product obtained from the resin composition. Specifically, when 2-ethylhexyl (2-hydroxyethyl) terephthalate is included as the main component of a plasticizer composition, its relatively low molecular weight makes it difficult to blend with the resin, and subsequent rolling processes, such as those performed after blending, may not proceed smoothly. When the 2-ethylhexyl (2-hydroxyethyl) terephthalate content falls within the preferred range, an appropriate volatility loss and absorption rate are achieved, thereby providing a plasticizer composition with excellent heat resistance and stable blendability with the resin composition.

[0058] Furthermore, polyethylene terephthalate (PET) contains a trace amount of isophthalate (an isomer of terephthalate) in its molecular structure. This isophthalate structure can be converted into di(2-ethylhexyl) isophthalate through the aforementioned esterification reaction process. In the typical reaction process for recovering di(2-ethylhexyl) terephthalate from PET, this di(2-ethylhexyl) isophthalate is considered an impurity, and therefore all of it is removed from the final composition. However, in the present invention, based on the fact that the partial inclusion of di(2-ethylhexyl) isophthalate in the plasticizer composition can achieve better physical properties than when using terephthalate alone while maintaining a balance of physical properties, the plasticizer composition of the present invention is obtained by retaining di(2-ethylhexyl) isophthalate in the plasticizer composition without removing it.

[0059] Because the isophthalate content in the PET starting material is low, the content of di(2-ethylhexyl)isophthalate in the plasticizer composition of the present invention obtained from PET is also low. Specifically, the content can be 5 wt% or less, preferably 0.3 wt% to 3 wt%, based on the total composition. Due to the structure of the PET starting material, it is difficult to increase the di(2-ethylhexyl)isophthalate content above the above range. Furthermore, when the di(2-ethylhexyl)isophthalate content is below the above range, the improvement effect of di(2-ethylhexyl)isophthalate is not significant.

[0060] According to one embodiment of the present invention, the plasticizer composition of the present invention may further comprise one or more of the dimer compounds represented by the following formulae 1 to 3.

[0061] [Formula 1]

[0062] [Formula 2]

[0063] [Formula 3]

[0064] In the present invention, a dimer compound having a (phthalate or isophthalate)-(ethylene glycol)-(phthalate or isophthalate) structure (one of the by-products) of the aforementioned 2-ethylhexyl (2-hydroxyethyl) terephthalate is controlled to be contained in a plasticizer composition at a predetermined content, thereby providing a plasticizer composition having improved properties compared to typical plasticizer products. Isophthalate can be produced during the plasticizer composition preparation process by using recycled polyethylene terephthalate (PET) as a raw material and by residual high-purity isophthalic acid (Isophthalic Acid), a small amount of which is used in the production of PET.

[0065] These dimer compounds can be prepared in various forms and concentrations depending on the type of alcohol used and the reaction conditions in the depolymerization process of PET. Furthermore, since compounds having this structure are included in the plasticizer composition along with a terephthalate-based plasticizer, they can complement the compression migration of typical terephthalate-based plasticizers.

[0066] For example, in the process of synthesizing di(2-ethylhexyl) terephthalate (which is a monomer) by reacting 2-ethylhexanol with PET, a dimer compound in which 2-ethylhexanol is bonded to each terminal of two terephthalic acids can be generated, and the dimer compound can be included in the final plasticizer composition.

[0067] The above-mentioned process for forming the dimer compound is an example. In addition to the above-mentioned formation process, various combinations of dimer compounds can be formed by various reactions between 2-ethylhexyl (2-hydroxyethyl) phthalate and 2-ethylhexyl (2-hydroxyethyl) isophthalate.

[0068] Furthermore, the content of bis(2-ethylhexyl) terephthalate, 2-ethylhexyl(2-hydroxyethyl) terephthalate, and the dimer compound can be controlled by deliberately controlling the transesterification reaction in the aforementioned preparation method. Furthermore, when the reaction time during the transesterification reaction is controlled, relatively large amounts of byproducts such as trimer and / or tetramer compounds and dimer compounds may be generated depending on the reaction time. However, since these byproducts maintain the final processing physical properties of the overall plasticizer composition of bis(2-ethylhexyl) terephthalate and 2-ethylhexyl(2-hydroxyethyl) terephthalate at a usable level without degrading the properties, the reaction product containing these byproducts can be used as a plasticizer composition as is.

[0069] Furthermore, the content of the dimer compound can be determined based on the amount of catalyst used in the preparation method, the amount of 2-ethylhexanol to be added, the reaction pressure and temperature, the reaction progression time, and the like. Specifically, as the amount of 2-ethylhexanol to be added increases, the content of the condensate and dimer decreases. In the plasticizer composition provided by the present invention, the total content of the dimer compound in the composition can be 2.0 wt% to 20.0 wt%. For example, the total content of the dimer compound in the composition can be 2.0 wt% or more, 3.0 wt% or more, 4.0 wt% or more, 5.0 wt% or more, 6.0 wt% or more, 7.0 wt% or more, 8.0 wt% or more, 20.0 wt% or less, 19.0 wt% or less, 18.0 wt% or less, 17.0 wt% or less, 16.0 wt% or less, 15.0 wt% or less, 14.0 wt% or less, 13.0 wt% or less, or 12.0 wt% or less. Preferably, the total content of the dimer compound in the composition can be 2.0 wt% to 15.0 wt%. When the content of the dimer compound is controlled within the above range, a plasticizer composition can be provided that has anti-migration and volatility loss properties that are equal to or higher than those of typical plasticizer products, as well as excellent mechanical properties such as tensile strength and tensile residual rate, and stress resistance.

[0070] Furthermore, the compounds represented by Formulas 1 to 3 above may be present simultaneously in the plasticizer composition. In the plasticizer composition provided by the present invention, the content of the dimer compound represented by Formula 1 above may be 0.01 wt% to 1 wt%, the content of the dimer compound represented by Formula 2 above may be 1.5 wt% to 17.0 wt%, and the content of the dimer compound represented by Formula 3 above may be 0.3 wt% to 2.5 wt%.

[0071] Specifically, the content of the dimer compound represented by Formula 1 above may be 0.01 wt % or more, 0.02 wt % or more, 0.03 wt % or more, 0.04 wt % or more, 0.05 wt % or more, 0.10 wt % or more, 0.20 wt % or more, 0.40 wt % or more, 1.0 wt % or less, 0.90 wt % or less, 0.80 wt % or less, 0.70 wt % or less, 0.60 wt % or less, or 0.50 wt % or less.

[0072] Furthermore, specifically, the content of the dimer compound represented by Formula 2 above may be 1.5 wt % or more, 1.7 wt % or more, 1.8 wt % or more, 2.0 wt % or more, 2.5 wt % or more, 2.7 wt % or more, 3.0 wt % or more, 3.5 wt % or more, 3.7 wt % or more, 4.0 wt % or more, 5.0 wt % or more, 17.0 wt % or less, 16.0 wt % or less, 15.0 wt % or less, 14.0 wt % or less, 13.0 wt % or less, 12.0 wt % or less, 11.0 wt % or less, 10.0 wt % or less, 9.0 wt % or less, 8.0 wt % or less, 7.0 wt % or less, 6.0 wt % or less, 7.0 wt % or less, or 6.0 wt % or less.

[0073] Furthermore, specifically, the content of the dimer compound represented by the above formula 3 may be 0.3 wt % or more, 0.4 wt % or more, 0.5 wt % or more, 0.7 wt % or more, 1.0 wt % or more, 1.1 wt % or more, 1.2 wt % or more, 1.3 wt % or more, 1.5 wt % or more, 2.5 wt % or less, 2.4 wt % or less, 2.3 wt % or less, 2.1 wt % or less, 2.0 wt % or less, 1.7 wt % or less, 1.5 wt % or less, 1.3 wt % or less, 1.2 wt % or less, or 1.1 wt % or less.

[0074] When the content of each of the dimer compounds represented by the above formulae 1 to 3 satisfies the above range, the effect of improving the anti-migration property and the volatilization loss in the processing properties of the resin can be achieved.

[0075] Furthermore, the weight ratio of the dimer compound to 2-ethylhexyl (2-hydroxyethyl) terephthalate in the composition may be 1:0.001 to 5.0, for example, 1:0.01 or greater, 0.02 or greater, 0.05 or greater, 0.1 or greater, 0.2 or greater, 0.5 or greater, 0.7 or greater, 1.0 or greater, 1.5 or greater, 5.0 or less, 4.7 or less, 4.5 or less, 4.2 or less, 4.0 or less, 3.7 or less, 3.5 or less, 3.2 or less, 3.0 or less, 2.7 or less, 2.5 or less, 2.3 or less, 2.0 or less, 1.7 or less, 1.5 or less, 1.2 or less, 1.0 or less, or 0.8 or less. Preferably, the weight ratio of the dimer compound to 2-ethylhexyl (2-hydroxyethyl) terephthalate is 1:0.01 to 0.8. When the weight ratio of the dimer compound to 2-ethylhexyl (2-hydroxyethyl) terephthalate in the plasticizer composition falls within the above range, excellent anti-migration properties can be achieved, as well as excellent volatility loss and absorption rates, allowing for smooth blending with the resin and subsequent rolling processes, thereby enhancing processing stability.

[0076] In addition, the weight ratio of the dimer compound to di(2-ethylhexyl) terephthalate in the composition may be 1:2.0 to 99.0, for example, 1:2.0 or greater, 2.5 or greater, 2.7 or greater, 3.0 or greater, 3.5 or greater, 4.0 or greater, 4.5 or greater, 5.0 or greater, 6.0 or greater, 7.0 or greater, 9.0 or greater, 10.0 or greater, 12.0 or greater, 15.0 or greater. , 20.0 or more, 25.0 or more, 27.0 or more, 30.0 or more, 35.0 or more, 99.0 or less, 95.0 or less, 92.0 or less, 90.0 or less, 85.0 or less, 80.0 or less, 75.0 or less, 70.0 or less, 65.0 or less, 60.0 or less, 55.0 or less, 50.0 or less, 45.0 or less, or 40.0 or less. Preferably, the weight ratio of the dimer compound to di(2-ethylhexyl) terephthalate in the composition may be 1:2.7 to 45. When the ratio of the dimer compound to di(2-ethylhexyl) terephthalate is within the above range, the effect of improving the anti-migration property achieved by including the dimer compound in the plasticizer composition can be maximized. [] []

[0077] The method for hydrogenating the plasticizer composition of the present invention can be applied. The present invention provides a plasticizer composition comprising 2-ethylhexyl (2-hydroxyethyl) cyclohexane-1,4-dicarboxylate, di(2-ethylhexyl) cyclohexane-1,3-dicarboxylate, and di(2-ethylhexyl) cyclohexane-1,4-dicarboxylate, wherein the content of 2-ethylhexyl (2-hydroxyethyl) cyclohexane-1,4-dicarboxylate is 20 wt% or less based on the total plasticizer composition. In addition, the plasticizer composition may further include hydrides of the dimer compounds represented by Formulas 1 to 4.

[0078] A plasticizer composition comprising 2-ethylhexyl(2-hydroxyethyl)cyclohexane-1,4-dicarboxylate, di(2-ethylhexyl)cyclohexane-1,3-dicarboxylate, and di(2-ethylhexyl)cyclohexane-1,4-dicarboxylate can be obtained by hydrogenating a product produced by a transesterification reaction between polyethylene terephthalate (PET) and 2-ethylhexanol. The order of the transesterification and hydrogenation reactions may be reversed. The product comprises the aforementioned 2-ethylhexyl (2-hydroxyethyl) terephthalate, di(2-ethylhexyl) isophthalate, and di(2-ethylhexyl) terephthalate, and may further comprise dimer compounds of formulas 1 to 4.

[0079] The plasticizer composition can significantly improve migration and loss properties while eliminating environmental issues, and can achieve products with significantly improved light resistance and heat resistance compared to typical commercial products. [] []

[0080] Method for preparing plasticizer composition

[0081] The present invention provides a method for preparing the plasticizer composition.

[0082] Specifically, the present invention provides a method for preparing a plasticizer composition, wherein the method comprises mixing polyethylene terephthalate and 2-ethylhexanol in the presence of a catalyst to conduct an esterification reaction, wherein the esterification reaction product comprises 2-ethylhexyl (2-hydroxyethyl) terephthalate, di(2-ethylhexyl) isophthalate, and di(2-ethylhexyl) terephthalate. Furthermore, the product may further comprise any one or more of the dimer compounds represented by Formulas 1 to 3 above.

[0083] PET and 2-ethylhexanol are converted into a composition containing these three components through a transesterification reaction. Specifically, PET is represented by the following formula (a).

[0084] [Formula a]

[0085] In the transesterification reaction of PET and 2-ethylhexanol, 2-ethylhexanol reacts with ester groups present in PET, thereby releasing the polymerization chains of PET. Depending on the control of the reaction, the ratio of the two components can be controlled. Importantly, not only the ratio of the three components but also the ratio of the dimer compound can be controlled within the above range.

[0086] Based on the combined content of PET and 2-ethylhexanol, PET may be included in an amount of 80 wt% or less, preferably 60 wt% or less, and more preferably 50 wt%, 40 wt%, or 35 wt% or less. When the PET content is within the above range, the amount of 2-ethylhexanol added is sufficient, thereby minimizing side reactions and maximizing the desired transesterification reaction between PET and 2-ethylhexanol. Specifically, when the PET content is within the above range, the composition obtained through the preparation process meets the above-mentioned preferred content conditions, thereby having the advantage of directly preparing a plasticizer composition with excellent physical properties while minimizing post-treatment after the preparation process.

[0087] Furthermore, the PET may contain 50 wt% or more of waste PET, preferably 60 wt% or more, and even more preferably 70 wt% or more. Even with the use of waste PET, the component ratio in the final product remains unchanged. Therefore, as long as the color and plasticizer impurity levels can be controlled, waste PET can be used entirely. Using waste PET as described above offers significantly superior cost competitiveness compared to di(2-ethylhexyl) terephthalate produced from terephthalic acid or dimethyl terephthalate. This reduces energy consumption for producing terephthalic acid or dimethyl terephthalate, and prevents environmental pollution, significantly contributing to environmental improvement.

[0088] In the preparation method according to one embodiment of the present invention, byproducts generated during the reaction, such as ethylene glycol, can be recycled outside the system, with some remaining in the reaction system. When some ethylene glycol remains in the reaction system to participate in the reaction, appropriate levels of 2-ethylhexyl (2-hydroxyethyl) terephthalate and dimer compounds of Formulas 1 to 3 can be formed from the remaining ethylene glycol. Furthermore, because 2-ethylhexyl (2-hydroxyethyl) terephthalate and dimer compounds of Formulas 1 to 3 contribute to improved properties of the plasticizer composition, additional energy is not required to remove the formed 2-ethylhexyl (2-hydroxyethyl) terephthalate and dimer compounds of Formulas 1 to 3, thereby enabling economical operation of the preparation process. Specifically, since ethylene glycol is used as a reactant to form 2-ethylhexyl (2-hydroxyethyl) terephthalate and the dimer compounds of Formulas 1 to 3, the ethylene glycol content in the final composition is naturally extremely reduced, thereby simplifying the separation process.

[0089] Examples of the catalyst may be one or more selected from the following: acid catalysts such as sulfuric acid, hydrochloric acid, phosphoric acid, nitric acid, paratoluenesulfonic acid, methanesulfonic acid, ethanesulfonic acid, propanesulfonic acid, butanesulfonic acid, and alkyl sulfuric acid; metal salts such as aluminum lactate, lithium fluoride, potassium chloride, cesium chloride, calcium chloride, ferric chloride, and phosphoric acid; metal oxides such as heteropoly acids; natural / synthetic zeolites; cation and anion exchange resins; catalysts comprising choline compounds such as choline hydroxide, choline bicarbonate, choline chloride, choline hydrogen stannate, choline dihydrogen citrate, and choline sulfate; organometallics such as alkyl titanates such as tetraalkyl titanates; titanate) or a polymer thereof; and an organometallic containing zirconium or tin. Preferably, the catalyst may be a tetraalkyl titanate.

[0090] The amount of catalyst to be used may vary depending on its type. In one example, based on 100 wt% of the reactants, a homogeneous catalyst may be used in an amount ranging from 0.01 to 5 wt%, 0.01 to 3 wt%, 1 to 5 wt%, or 2 to 4 wt%, and based on the total weight of the reactants, a heterogeneous catalyst may be used in an amount ranging from 5 to 200 wt%, 5 to 100 wt%, 20 to 200 wt%, or 20 to 150 wt%.

[0091] According to one embodiment of the present invention, the transesterification reaction is preferably conducted at a reaction temperature of 120°C to 240°C, preferably 135°C to 230°C, and more preferably 141°C to 220°C, for 10 minutes to 12 hours, preferably 30 minutes to 10 hours, and more preferably 1 to 8 hours. Within this temperature and time range, the composition ratio of the final plasticizer composition can be efficiently controlled. In this case, the reaction time can be calculated from the time the temperature of the reactants is raised to the time the reaction temperature is reached.

[0092] Furthermore, the method may further include a step of removing unreacted 2-ethylhexanol and ethylene glycol (reaction byproducts) after the transesterification reaction is complete. Since ethylene glycol has a high solubility in water, it can be removed through neutralization and washing with water after the reaction is complete. Residual 2-ethylhexanol can be removed through extractive distillation after neutralization and washing with water. Through these steps, a plasticizer composition having the required components and composition ratios can be prepared.

[0093] According to another embodiment of the present invention, a resin composition comprising the aforementioned plasticizer composition and a resin is provided.

[0094] Resins known in the art can be used as the resin. For example, a mixture of one or more selected from the group consisting of linear vinyl chloride polymers, pasty vinyl chloride polymers, ethylene-vinyl acetate copolymers, ethylene polymers, propylene polymers, polyketones, polystyrene, polyurethane, polylactic acid, natural rubber, synthetic rubber, and thermoplastic elastomers can be used as the resin. However, the present invention is not limited thereto.

[0095] Based on 100 parts by weight of the resin, the plasticizer composition may be included in an amount of 5 to 150 parts by weight, preferably 5 to 130 parts by weight, or 10 to 120 parts by weight.

[0096] Generally, a resin using a plasticizer composition can be processed into a resin product through melt processing or plastisol processing. Depending on the polymerization method, melt-processed resins and plastisol-processed resins can be produced differently.

[0097] For example, when vinyl chloride polymer is melt-processed, solid resin particles with a large average particle size produced by suspension polymerization or the like are used, and this vinyl chloride polymer is called a straight vinyl chloride polymer. When used in plastisol processing, sol-like resins with fine resin particles produced by emulsion polymerization or the like are used, and this vinyl chloride polymer is called a paste vinyl chloride resin.

[0098] At this time, in the case of a linear vinyl chloride polymer, the plasticizer is preferably included in an amount of 5 to 80 parts by weight based on 100 parts by weight of the polymer, and in the case of a paste vinyl chloride polymer, the plasticizer is preferably included in an amount of 40 to 120 parts by weight based on 100 parts by weight of the polymer.

[0099] The resin composition may further include a filler. Based on 100 parts by weight of the resin, the filler may be present in an amount of 0 to 300 parts by weight, preferably 50 to 200 parts by weight, and more preferably 100 to 200 parts by weight.

[0100] The filler may be any filler known in the art and is not particularly limited. For example, the filler may be a mixture of one or more selected from silica, magnesium carbonate, calcium carbonate, hard coal, talc, magnesium hydroxide, titanium dioxide, magnesium oxide, calcium hydroxide, aluminum hydroxide, aluminum silicate, magnesium silicate, and barium sulfate.

[0101] Furthermore, the resin composition may optionally contain other additives, such as stabilizers. Based on 100 parts by weight of the resin, the amount of such additives may be 0 to 20 parts by weight, preferably 1 to 15 parts by weight.

[0102] The stabilizer may be, for example, a calcium-zinc-based (Ca-Zn-based) stabilizer, such as a calcium-zinc complex stearic acid salt, or a barium-zinc-based (Ba-Zn-based) stabilizer, but is not particularly limited thereto.

[0103] As described above, the resin composition can be used for both melt processing and plastisol processing. For example, car-rendering processing, extrusion processing, or injection processing can be used as melt processing, while coating processing or the like can be used as plastisol processing.

[0104] [Example]

[0105] The present invention is described in detail below with reference to examples. However, the embodiments of the present invention may be modified into various other forms, and the scope of the present invention should not be construed as being limited to the embodiments described below. These embodiments are provided to more fully illustrate the present invention to those skilled in the art.

[0106] [Example] [1]

[0107] 1.5 g of a catalyst (TnBT), 500 g of discarded polyethylene terephthalate, and 1220 g of 2-ethylhexanol were added to a reactor equipped with a stirrer, condenser, and decanter. A transesterification reaction was then carried out at a temperature of 150°C to 230°C under a nitrogen atmosphere for 3 to 8 hours. After the reaction was complete, unreacted 2-ethylhexanol was removed by decompression. Subsequently, 100 g of a 3 wt% aqueous sodium hydroxide solution was added to neutralize the catalyst, and a small amount of unreacted 2-ethylhexanol was removed by distillation. Through the above process, a composition containing 12.4 wt%, 2.1 wt%, and 71 wt% of 2-hydroxyethyl(2-ethylhexyl) terephthalate, di(2-ethylhexyl) isophthalate, and di(2-ethylhexyl) terephthalate (DEHTP), respectively, was obtained. Components other than these three components in the composition included by-products generated during the reaction process, and these by-products contained dimer compounds in the amounts shown in Table 1 below.

[0108] [Example] [2]

[0109] By controlling the input amount of 2-ethylhexanol and the reaction time, a composition containing 7.2 wt%, 2 wt%, and 78.5 wt% of 2-hydroxyethyl (2-ethylhexyl) terephthalate, di(2-ethylhexyl) isophthalate, and di(2-ethylhexyl) terephthalate (DEHTP), respectively, was obtained in the same manner as in Example 1. Components other than these three components in the composition included byproducts generated during the reaction process, and these byproducts contained dimer compounds in the amounts shown in Table 1 below.

[0110] [Example] [3]

[0111] By controlling the input amount of 2-ethylhexanol and the reaction time, a composition containing 4.9 wt %, 1.75 wt %, and 90.3 wt % of 2-hydroxyethyl (2-ethylhexyl) terephthalate, di(2-ethylhexyl) isophthalate, and di(2-ethylhexyl) terephthalate (DEHTP), respectively, was obtained in the same manner as in Example 1. The remaining components of the composition, excluding these three components, comprised byproducts generated during the reaction process, and these byproducts included dimer compounds in the amounts shown in Table 1 below.

[0112] [Example] [4]

[0113] By controlling the input amount of 2-ethylhexanol and the reaction time, a composition containing 0.06 wt %, 1.9 wt %, and 95.8 wt % of 2-hydroxyethyl (2-ethylhexyl) terephthalate, di(2-ethylhexyl) isophthalate, and di(2-ethylhexyl) terephthalate (DEHTP), respectively, was obtained in the same manner as in Example 1. Components other than these three components in the composition included byproducts generated during the reaction process, and these byproducts contained dimer compounds in the amounts shown in Table 1 below.

[0114] [Example] [5]

[0115] By controlling the input amount of 2-ethylhexanol and the reaction time, a composition containing 19.1 wt %, 2 wt %, and 58.9 wt % of 2-hydroxyethyl (2-ethylhexyl) terephthalate, di(2-ethylhexyl) isophthalate, and di(2-ethylhexyl) terephthalate (DEHTP), respectively, was obtained in the same manner as in Example 1. The remaining components of the composition, excluding these three components, comprised byproducts generated during the reaction process, and these byproducts contained dimer compounds at the levels shown in Table 1 below.

[0116] [Comparative Example] [1]

[0117] Di(2-ethylhexyl) phthalate (DEHP, a product of LG Chem) was used as the plasticizer composition.

[0118] [Comparative Example] [2]

[0119] In the same manner as in Example 1, except that 1400 g of 2-ethylhexanol was added to remove all 2-hydroxyethyl (2-ethylhexyl) terephthalate in the composition, a composition containing 99.9 wt % of di(2-ethylhexyl) terephthalate (DEHTP) was obtained.

[0120] [Comparative Example] [3]

[0121] By controlling the input amount of 2-ethylhexanol and the reaction time, a composition was obtained in the same manner as in Example 1. A composition containing 2.1 wt% of di(2-ethylhexyl)isophthalate and 96.7 wt% of di(2-ethylhexyl)terephthalate (DEHTP) was obtained, excluding 2-hydroxyethyl(2-ethylhexyl)terephthalate. The remaining components of the composition, excluding these two components, included byproducts generated during the reaction process, and these byproducts contained dimer compounds at the levels shown in Table 1 below.

[0122] [Comparative Example] [4]

[0123] By controlling the input amount of 2-ethylhexanol and the reaction time, a composition containing 21.5 wt%, 1.5 wt%, and 55.2 wt% of 2-hydroxyethyl (2-ethylhexyl) terephthalate, di(2-ethylhexyl) isophthalate, and di(2-ethylhexyl) terephthalate (DEHTP), respectively, was obtained in the same manner as in Example 1. The remaining components of the composition, excluding these three components, comprised byproducts generated during the reaction process, and these byproducts included dimer compounds in the amounts shown in Table 1 below.

[0124]

[0125] Experimental Example 1: Evaluation of Sheet Performance

[0126] Using the plasticizers from the Examples and Comparative Examples, specimens were manufactured using the following formulations and manufacturing conditions according to ASTM D638.

[0127] [(1)] Prescription 100 parts by weight of straight vinyl chloride polymer (LS100), 50 parts by weight of plasticizer, and 3 parts by weight of stabilizer (BZ-153T)

[0128] [(2)] Blending [:] Mix at 98°C at 700 rpm

[0129] [(3)] Producing specimen [:] Roll mill at 160°C for 4 minutes and press at 180°C for 2.5 minutes (low pressure) and 2 minutes (high pressure) to produce 1T to 3T sheets

[0130] [(4)] Evaluation item

[0131] 1) Tensile Strength: 1T specimens were pulled using the ASTM D638 method using a UTM tester (Instron, Model 4466) at a crosshead speed of 200 mm / min. The point at which the specimens broke was measured. Tensile strength was calculated as follows.

[0132] Tensile strength (kgf / cm2) = load value (kgf) / thickness (cm) × width (cm)

[0133] 2) Elongation rate measurement: Using the ASTM D638 method, a 1T specimen was stretched using a UTM at a crosshead speed of 200 mm / min and the point at which the 1T specimen broke was measured. The elongation was calculated as follows:

[0134] Elongation (%) = length after elongation / initial length × 100

[0135] 3) Measurement of tension and elongation residual: The measurement of tension and elongation residual is used to measure the tensile strength and elongation remaining in the specimen after applying heat to 100°C for 168 hours, and the measurement method is the same as the tensile strength and elongation measurement method.

[0136] 4) Migration loss measurement: This measurement was performed in accordance with KSM-3156. Specifically, a test piece with a thickness of 1 mm was prepared, and absorbent sheets were attached to both sides of the test piece, capable of moving to absorb organic material discharged onto the test piece's surface. A plate covering the entire test piece was then attached to the test piece, applying a load of 1 kgf / cm². The test piece was placed in a hot air circulating oven (80°C) for 72 hours, then removed from the oven and cooled at room temperature for 4 hours. The plate and absorbent sheets attached to both sides of the test piece were then removed. The weight of the sample before and after exposure to the oven was measured to calculate the migration loss using the following equation 3.

[0137] Migration loss (%) = {(initial weight of the sample at room temperature - weight of the sample after standing in the oven) / initial weight of the sample at room temperature} × 100

[0138] 5) Volatile loss measurement: After treating the manufactured sample at 80°C for 72 hours, measure the weight of the sample.

[0139] Volatile loss (wt%) = initial sample weight - (80℃, sample weight after 72 hours of treatment) / initial sample weight × 100

[0140] 6) Stress Test (Stress Resistance): Bend a 2 mm thick specimen and allow it to rest at 23°C for 168 hours. Observe the degree of migration (leakage) on the first, third, and seventh days, and report the results numerically. The closer the value is to 0, the better the stress resistance.

[0141] 7) Carbonization Properties Evaluation: 0.25 mm thick specimens were prepared into 40 cm × 1 cm pieces and subjected to a carbonization test in a Mathis oven at 230°C at a rate of 5 mm / 10 sec. The onset of black carbonization was measured. Excellent carbonization properties indicate a relatively late onset of carbonization, while poor carbonization properties indicate a relatively early onset of carbonization. The evaluation was based on a scale of 1 to 5, with 5 being excellent and 1 being inferior.

[0142] 8) Absorption rate measurement: Processability was evaluated by measuring the time it took for the resin and plasticizer to be mixed with each other using a planetary mixer (Brabender, P600) at 73°C and 60 rpm until the mixer torque stabilized.

[0143] [(5)] [Evaluation Results]

[0144] The evaluation results of the projects are shown in Tables 2 and 3 below.

[0145]

[0146]

[0147] As shown in Tables 2 and 3 above, Examples 1 to 5 demonstrate superior results in terms of volatile loss, mechanical properties, stress resistance, and carbonization properties compared to Comparative Example 1, a typical phthalate-based plasticizer product. This means that the plasticizer composition of the present invention, utilizing both bis(2-ethylhexyl) phthalate and 2-ethylhexyl (2-hydroxyethyl) phthalate, exhibits improvements in volatile loss, stress resistance, and mechanical properties without degrading typical physical properties. Typically, when two-component compositions are mixed, the effects of the mixed composition tend to decrease the effectiveness of each component. However, in contrast, the present invention achieves improvements in stress resistance and mechanical properties while maintaining physical properties comparable to conventional methods. This confirms that the present invention achieves effects not anticipated by conventional methods.

[0148] Comparative Example 2 was prepared from polyethylene terephthalate in a similar manner to the examples of the present invention, except that a larger amount of 2-ethylhexanol was used, and the 2-ethylhexyl (2-hydroxyethyl) terephthalate in the final composition was completely removed through an additional separation process. While the manufacturing process cost was higher than that of Examples 1 to 5, the resulting plasticizer composition had similar physical properties to those of Examples 1 to 5. In particular, the results for migration resistance, stress resistance, and mechanical properties were inferior to those of the examples. Furthermore, the absorption rate was inferior to that of the examples. The foregoing demonstrates that the plasticizer composition of the present invention has a lower production cost than typical plasticizer compositions containing di(2-ethylhexyl) terephthalate recovered from polyethylene terephthalate, and that the plasticizer itself exhibits excellent functionality.

[0149] Furthermore, Comparative Examples 3 and 4 were prepared from polyethylene terephthalate in a manner similar to the examples of the present invention. By controlling the input amount of 2-ethylhexanol, reaction time, and purification process, the plasticizer compositions contained 2-ethylhexyl (2-hydroxyethyl) terephthalate and / or dimer compounds exceeding the content of the present invention. However, the mechanical properties, migration loss, volatilization loss, and stress resistance of the plasticizer compositions were inferior to those of the above examples. This confirms that the plasticizer compositions of the present invention, in which the content of each compound is limited to maximize improvements in various physical properties such as mechanical properties, heat resistance, and migration resistance, exhibit superior plasticizer functionality compared to the plasticizers of Comparative Examples 2 and 3, in which the content of 2-ethylhexyl (2-hydroxyethyl) terephthalate and / or dimer compounds is excessive.

Claims

1. A plasticizer composition comprising 2-ethylhexyl(2-hydroxyethyl) terephthalate, di(2-ethylhexyl) isophthalate, and di(2-ethylhexyl) terephthalate, wherein, The content of 2-ethylhexyl (2-hydroxyethyl) phthalate is 0.01 wt% to 20 wt% based on the total plasticizer composition.

2. The plasticizer composition as claimed in claim 1, wherein, The content of 2-ethylhexyl(2-hydroxyethyl) phthalate is from 0.01 wt% to 15 wt%.

3. The plasticizer composition as claimed in claim 1, wherein, The weight ratio between 2-ethylhexyl (2-hydroxyethyl) p-phthaloate and di(2-ethylhexyl) p-phthaloate is 1:3 to 10000.

4. The plasticizer composition as claimed in claim 3, wherein, The weight ratio between 2-ethylhexyl (2-hydroxyethyl) p-phthaloate and di(2-ethylhexyl) p-phthaloate is 1:5 to 1000.

5. The plasticizer composition as claimed in claim 1, wherein, The content of di(2-ethylhexyl) isophthalate is 5.0 wt% or less based on the total composition.

6. The plasticizer composition of claim 1 further comprises one or more of the dimer compounds represented by the following formulas 1 to 3: [Formula 1] [Formula 2] [Formula 3].

7. The plasticizer composition as claimed in claim 6, wherein, The total content of the dimer compound in the composition is from 2.0 wt% to 20.0 wt%.

8. The plasticizer composition as claimed in claim 6, wherein, The content of the dimer compound represented by Formula 1 in the composition is from 0.01 wt% to 1 wt%.

9. The plasticizer composition as claimed in claim 6, wherein, The content of the dimer compound represented by Formula 3 in the composition is from 0.3 wt% to 2.5 wt%.

10. The plasticizer composition as claimed in claim 6, wherein, The weight ratio of the dimer compound to 2-ethylhexyl (2-hydroxyethyl) phthalate in the composition is from 1:0.001 to 5.

11. The plasticizer composition as claimed in claim 6, wherein, The weight ratio of the dimer compound to di(2-ethylhexyl) phthalate in the composition is from 1:2.0 to 99.

0.

12. A method for preparing a plasticizer composition, the method comprising the step of mixing polyethylene terephthalate and 2-ethylhexanol in the presence of a catalyst to carry out an esterification reaction, wherein, The products of the esterification reaction include 2-ethylhexyl (2-hydroxyethyl) p-phthaloate, di(2-ethylhexyl) isophthaloate, and di(2-ethylhexyl) p-phthaloate.

13. As in request item 12, wherein, Poly(p-phthalic acid) is mixed in an amount of 80 wt% or less relative to the total content of polyethylene terephthalate and 2-ethylhexanol.

14. As in request item 12, wherein, Poly(p-phthalate) includes both discarded and recycled polyethylene terephthalate.

15. A resin composition comprising: 100 parts by weight of a resin; and 5 to 150 parts by weight of a plasticizer composition as claimed in claim 1, wherein, The resin is selected from one or more of the following groups: straight vinyl chloride polymer, paste vinyl chloride polymer, ethylene-vinyl acetate copolymer, ethylene polymer, propylene polymer, polyketone, polystyrene, polyurethane, polylactic acid, natural rubber, and synthetic rubber.